Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default How to fix my 5V, 2.5amp adapter.

How to fix my 5V, 2.5amp adapter.

I had 4 short power failures today, and everything on the PC started
up fine after the first 3. The fourth was longer so I went grocery
shopping.

When I restarted, none of the lights on the wireless router went on,
and an ohmmeter showed infinite resistance between the two prongs that
plug into the wall. I had a surge, didn't I?

Do you think I'll be able to fix this? An exact replacement is only
$7.50 but that's not the point. I want to fix what's broken.

I chiselled the case open and it has maybe 6 electrolytic capacitors.
None show the bursting top that I"ve heard about. It has a big
transistor and a little one, 2 big diodes, 2 little diodes, what might
be a transformer and another double winding, 2 or 3 resistors and a
couple little ceramic capacitors.

Right next to an AC prong, it has what looks like a fuse with
pigtails, silver ends, and a grey body (not glass) but it shows
continuity, 0.3 ohms. Right next to that is a yellow thing,
rectangular on all sides, labeled Carli. Might be a Metallized film
capacitor.

What should I look at first?


If I can't fix it, my router is b, g, seems fast enough for the
printer and the rare laptop use. (The computers themselves use cables
for connecting) But should I apply the 7.50 to an L router, or is
something better than that coming?


Thanks a lot.


P. S. This is what's broken:
http://www.ebay.com/itm/5V-2-5A-D-Li...3 01720248001

(Right now I'm using a universal digital camera AC adapter, that I
bought 20 years ago. I almost didn't buy it because I did't have a
digital camera and didn't expect to get one. Didn't get one for
another 10 years (and even it doesn't use an adapter like this.))


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Default How to fix my 5V, 2.5amp adapter.

On Friday, November 20, 2015 at 3:43:21 AM UTC-5, Micky wrote:
How to fix my 5V, 2.5amp adapter.

I had 4 short power failures today, and everything on the PC started
up fine after the first 3. The fourth was longer so I went grocery
shopping.

When I restarted, none of the lights on the wireless router went on,
and an ohmmeter showed infinite resistance between the two prongs that
plug into the wall. I had a surge, didn't I?

Do you think I'll be able to fix this? An exact replacement is only
$7.50 but that's not the point. I want to fix what's broken.


There is very likely a fusible link somewhere inside the wall-wart that might look something like this: http://www.ttiinc.com/props/IO/38458...-use-fuses.jpg or this: http://i00.i.aliimg.com/photo/v0/952...sible_link.jpg

Use your ohm meter to check and see if one is there and if it is open.

Good luck with it.

Peter Wieck
Melrose Park, PA
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Default How to fix my 5V, 2.5amp adapter.

On Fri, 20 Nov 2015 03:43:10 -0500, Micky
wrote:

How to fix my 5V, 2.5amp adapter.

I had 4 short power failures today, and everything on the PC started
up fine after the first 3. The fourth was longer so I went grocery
shopping.

When I restarted, none of the lights on the wireless router went on,
and an ohmmeter showed infinite resistance between the two prongs that
plug into the wall. I had a surge, didn't I?

Do you think I'll be able to fix this? An exact replacement is only
$7.50 but that's not the point. I want to fix what's broken.

I chiselled the case open and it has maybe 6 electrolytic capacitors.
None show the bursting top that I"ve heard about. It has a big
transistor and a little one, 2 big diodes, 2 little diodes, what might
be a transformer and another double winding, 2 or 3 resistors and a
couple little ceramic capacitors.

Right next to an AC prong, it has what looks like a fuse with
pigtails, silver ends, and a grey body (not glass) but it shows
continuity, 0.3 ohms. Right next to that is a yellow thing,
rectangular on all sides, labeled Carli. Might be a Metallized film
capacitor.

What should I look at first?


If I can't fix it, my router is b, g, seems fast enough for the
printer and the rare laptop use. (The computers themselves use cables
for connecting) But should I apply the 7.50 to an L router, or is
something better than that coming?


Thanks a lot.


P. S. This is what's broken:
http://www.ebay.com/itm/5V-2-5A-D-Li...3 01720248001

(Right now I'm using a universal digital camera AC adapter, that I
bought 20 years ago. I almost didn't buy it because I did't have a
digital camera and didn't expect to get one. Didn't get one for
another 10 years (and even it doesn't use an adapter like this.))

One of the capacitors that goes high esr and causes a power supply to
die if it cools off doesn't show any physical deterioration. Usually
47uf 50V.

---
This email has been checked for viruses by Avast antivirus software.
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Default How to fix my 5V, 2.5amp adapter.

On 11/20/2015 12:43 AM, Micky wrote:
How to fix my 5V, 2.5amp adapter.

I had 4 short power failures today, and everything on the PC started
up fine after the first 3. The fourth was longer so I went grocery
shopping.

When I restarted, none of the lights on the wireless router went on,
and an ohmmeter showed infinite resistance between the two prongs that
plug into the wall. I had a surge, didn't I?

Do you think I'll be able to fix this? An exact replacement is only
$7.50 but that's not the point. I want to fix what's broken.

I chiselled the case open and it has maybe 6 electrolytic capacitors.
None show the bursting top that I"ve heard about. It has a big
transistor and a little one, 2 big diodes, 2 little diodes, what might
be a transformer and another double winding, 2 or 3 resistors and a
couple little ceramic capacitors.

Right next to an AC prong, it has what looks like a fuse with
pigtails, silver ends, and a grey body (not glass) but it shows
continuity, 0.3 ohms. Right next to that is a yellow thing,
rectangular on all sides, labeled Carli. Might be a Metallized film
capacitor.

What should I look at first?


If I can't fix it, my router is b, g, seems fast enough for the
printer and the rare laptop use. (The computers themselves use cables
for connecting) But should I apply the 7.50 to an L router, or is
something better than that coming?


Thanks a lot.


P. S. This is what's broken:
http://www.ebay.com/itm/5V-2-5A-D-Li...3 01720248001

(Right now I'm using a universal digital camera AC adapter, that I
bought 20 years ago. I almost didn't buy it because I did't have a
digital camera and didn't expect to get one. Didn't get one for
another 10 years (and even it doesn't use an adapter like this.))


Bottom line...buy the new supply.
Problem with that one is the plug on the end is different from
most other router power supplies. Get the right one and be done with it.

I fix wall warts all the time for my own use. I'd never sell a gizmo
with a power supply that I repaired. Too much liability involved.

Most fail with shorted input diodes, but
that also blows the fuse.
I've been fixing stuff for almost half a century, but working on
line-connected
stuff still scares the hell out of me...and I've got a completely isolated
scope probe system.
Even if you do find out what's broke, where are you gonna get the
replacement part?
Putting it back together is problematic. What happens if you
try to unplug it and the glue breaks...you end up with AC in your
hands...not fun.

Look at the risk/reward ratio.
Best that can possibly happen is you save $7.50.
Worst is electrocution? burning down your house?
For stuff connected directly to the line,
if you don't know what you're doing, keep it that way.
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Default How to fix my 5V, 2.5amp adapter.

On Fri, 20 Nov 2015 03:43:10 -0500, Micky
wrote:

What should I look at first?


Ummm... perhaps Google for "JTA0302 repair"?
http://hardware-today.com/articles/networking_hardware/how_to_repair_power_supply_adapter_d_link_5v_2a_jt a0302d_e

Drivel: Here's my collection:
http://802.11junk.com/jeffl/pics/repair/
with a few wall wart repairs.
--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


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Default How to fix my 5V, 2.5amp adapter.

On Fri, 20 Nov 2015 11:47:59 -0600, Chuck wrote:

On Fri, 20 Nov 2015 03:43:10 -0500, Micky
wrote:

How to fix my 5V, 2.5amp adapter.

I had 4 short power failures today, and everything on the PC started
up fine after the first 3. The fourth was longer so I went grocery
shopping.

When I restarted, none of the lights on the wireless router went on,
and an ohmmeter showed infinite resistance between the two prongs that
plug into the wall. I had a surge, didn't I?

Do you think I'll be able to fix this? An exact replacement is only
$7.50 but that's not the point. I want to fix what's broken.

I chiselled the case open and it has maybe 6 electrolytic capacitors.
None show the bursting top that I"ve heard about. It has a big
transistor and a little one, 2 big diodes, 2 little diodes, what might
be a transformer and another double winding, 2 or 3 resistors and a
couple little ceramic capacitors.

Right next to an AC prong, it has what looks like a fuse with
pigtails, silver ends, and a grey body (not glass) but it shows
continuity, 0.3 ohms. Right next to that is a yellow thing,
rectangular on all sides, labeled Carli. Might be a Metallized film
capacitor.

What should I look at first?


If I can't fix it, my router is b, g, seems fast enough for the
printer and the rare laptop use. (The computers themselves use cables
for connecting) But should I apply the 7.50 to an L router, or is
something better than that coming?


Thanks a lot.


P. S. This is what's broken:
http://www.ebay.com/itm/5V-2-5A-D-Li...3 01720248001

One of the capacitors that goes high esr and causes a power supply to
die if it cools off doesn't show any physical deterioration. Usually
47uf 50V.


So you're suggesting there was no surge, but the lack of power let the
PS cool off and the capacitor fail! I never would have thought of
that. Also, you name the same cap that the url Jeff gave found was
bad (along with the zener diode).

And you're right, it looks fine.
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Default How to fix my 5V, 2.5amp adapter.

On Fri, 20 Nov 2015 13:03:27 -0800, Jeff Liebermann
wrote:

On Fri, 20 Nov 2015 03:43:10 -0500, Micky
wrote:

What should I look at first?


Ummm... perhaps


I recognize the sarcasm. ;-)

Google for "JTA0302 repair"?


It never occurred to me to do that. Wow, the perfect page.

http://hardware-today.com/articles/networking_hardware/how_to_repair_power_supply_adapter_d_link_5v_2a_jt a0302d_e


That's it all right. A slightly different arrangment, but all the
same parts.

And a schematic too! I have to spend a bunch of time looking at that.
Drivel: Here's my collection:
http://802.11junk.com/jeffl/pics/repair/
with a few wall wart repairs.


No kidding!

Thanks, and thanks all.
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On Fri, 20 Nov 2015 17:50:23 -0500, Micky
wrote:

On Fri, 20 Nov 2015 13:03:27 -0800, Jeff Liebermann
wrote:


I recognize the sarcasm. ;-)


I was on the phone with a very polite but useless support personality
possibly in India. I hope you don't mind me taking out my
frustrations on you.

It never occurred to me to do that. Wow, the perfect page.
http://hardware-today.com/articles/networking_hardware/how_to_repair_power_supply_adapter_d_link_5v_2a_jt a0302d_e


Yep. I usually don't get that lucky. I recently tried to repair one
of those by replacing 3 of the caps mentioned. It didn't work. Of
course, I didn't bother searching for info until after I had given up
and recycled the power supply. Do like I say, not like I do.

That's it all right. A slightly different arrangment, but all the
same parts.


There are A through E variations. I've only seen B and C which look
like the same board layout, but built by different contractors. I
don't know if there are any component value changes or schematic
variations.

And a schematic too! I have to spend a bunch of time looking at that.


You should be able to get some theory of operation in the data sheets
and app notes for the UC3843B chip:
https://www.google.com/search?q=uc3843b
http://www.st.com/st-web-ui/static/active/en/resource/technical/document/application_note/CD00003930.pdf

Drivel: Here's my collection:
http://802.11junk.com/jeffl/pics/repair/
with a few wall wart repairs.


No kidding!


I don't know why I bother trying to fix those. It's certainly not
making me any money. Worse, I've accumulated a fairly large
collection of wall warts that really need to be recycled instead of
occupying space.

"One day, son, all of these perfectly good A.C. adapters, which have
long outlived the products they were originally designed for, will be
yours."
http://www.newyorker.com/wp-content/uploads/2012/01/120116_a16285_g2048-600.jpg

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default How to fix my 5V, 2.5amp adapter.

In article , NONONOmisc07
@bigfoot.com says...

On Fri, 20 Nov 2015 13:03:27 -0800, Jeff Liebermann
wrote:

On Fri, 20 Nov 2015 03:43:10 -0500, Micky
wrote:

What should I look at first?


Ummm... perhaps


I recognize the sarcasm. ;-)

Google for "JTA0302 repair"?


It never occurred to me to do that. Wow, the perfect page.

http://hardware-today.com/articles/networking_hardware/how_to_repair_power_supply_adapter_d_link_5v_2a_jt a0302d_e


That's it all right. A slightly different arrangment, but all the
same parts.

And a schematic too! I have to spend a bunch of time looking at that.
Drivel: Here's my collection:
http://802.11junk.com/jeffl/pics/repair/
with a few wall wart repairs.


No kidding!

Thanks, and thanks all.


Its amazing how you guys can find schematics to these things.

I would check the primary side of the transformer, make sure
it didn't get opened from a latch on.

Also check that little blue thingy that is attached to the
line fuse feeding the common choke. You may need to do that under
power via a volt meter.

Have fun.

Jamie

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Default How to fix my 5V, 2.5amp adapter.

On Fri, 20 Nov 2015 18:26:39 -0500, M Philbrook
wrote:

Its amazing how you guys can find schematics to these things.


It's actually quite easy. Instead of searching the web, I do an image
search. Photos, schematics, disassembly instructions, and such are
much easier to find using images than text. You can text search for
"xxxxx schematic" but schematics are rarely titles with the word
"schematic" on the page.

If the photo is not quite what I want, such as Google image search
find a thumbnail instead of a full size image, I use one of several
reverse image searches to find the original:
https://support.google.com/websearch/answer/1325808?hl=en
https://www.tineye.com
etc...


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


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Default How to fix my 5V, 2.5amp adapter.

On Sat, 21 Nov 2015 13:19:22 -0500, M Philbrook
wrote:

In article ,
says...

On Fri, 20 Nov 2015 18:26:39 -0500, M Philbrook
wrote:

Its amazing how you guys can find schematics to these things.


It's actually quite easy. Instead of searching the web, I do an image
search. Photos, schematics, disassembly instructions, and such are
much easier to find using images than text. You can text search for
"xxxxx schematic" but schematics are rarely titles with the word
"schematic" on the page.

If the photo is not quite what I want, such as Google image search
find a thumbnail instead of a full size image, I use one of several
reverse image searches to find the original:
https://support.google.com/websearch/answer/1325808?hl=en
https://www.tineye.com
etc...


I'll keep that in mind, Thanks

Jamie


Me too. Thanks.

One more question.

If I couldnt' find a power supply for the router, until I bought a new
one, could I have just unplugged the wire from the DSL modem to the
router and plugged it into the computer? The only thing I'm doing
wirelessly now is print, and I don't print very often.

This idea kept popping in my head and then disappearing.
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On Sat, 21 Nov 2015 13:42:11 -0500, Micky
wrote:

One more question.


Sigh.

If I couldnt' find a power supply for the router, until I bought a new
one, could I have just unplugged the wire from the DSL modem to the
router and plugged it into the computer? The only thing I'm doing
wirelessly now is print, and I don't print very often.


Yes. 5V from the computer is the same as 5v from the Dlink wall wart.
I have a cable with a Molex connector to adapt from the disk drive
power connectors to some power plugs and cables that I hacked off some
dead wall warts. This kludge makes a handy adapter cable for exactly
what you're doing. I've used it when a customers wall wart dies, and
I need something temporary until I can either fix or replace the
original wall wart. If you can find the right size power plug, it
should work.

This idea kept popping in my head and then disappearing.


You probably have a black hole in your head. Black holes will suck
both good and bad ideas equally so don't use the prevalence or
disappearance of the idea as a figure of merit.


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default How to fix my 5V, 2.5amp adapter.

On Sat, 21 Nov 2015 11:28:39 -0800, Jeff Liebermann
wrote:

On Sat, 21 Nov 2015 13:42:11 -0500, Micky
wrote:

One more question.


Sigh.


This is the price you pay for your earlier sarcasm.

If I couldnt' find a power supply for the router, until I bought a new
one, could I have just unplugged the wire from the DSL modem to the
router and plugged it into the computer? The only thing I'm doing
wirelessly now is print, and I don't print very often.


Yes. 5V from the computer is the same as 5v from the Dlink wall wart.


No, no 5v at all. I mean eliminating the router and going straight
from the DSL modem to the network card in the computer. That's the
default, isn't it? It's only been 8 years but I can't remember.

I have a cable with a Molex connector to adapt from the disk drive
power connectors to some power plugs and cables that I hacked off some
dead wall warts. This kludge makes a handy adapter cable for exactly
what you're doing. I've used it when a customers wall wart dies, and
I need something temporary until I can either fix or replace the
original wall wart. If you can find the right size power plug, it
should work.

This idea kept popping in my head and then disappearing.


You probably have a black hole in your head.


Maybe I can get some Gorilla Tape. It's black too so it won't show
that much.

Black holes will suck
both good and bad ideas equally so don't use the prevalence or
disappearance of the idea as a figure of merit.



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On Fri, 20 Nov 2015 09:50:15 -0800, mike wrote:

On 11/20/2015 12:43 AM, Micky wrote:
How to fix my 5V, 2.5amp adapter.

I had 4 short power failures today, and everything on the PC started
up fine after the first 3. The fourth was longer so I went grocery
shopping.

When I restarted, none of the lights on the wireless router went on,
and an ohmmeter showed infinite resistance between the two prongs that
plug into the wall. I had a surge, didn't I?


Apparently it just cooled off!


P. S. This is what's broken:
http://www.ebay.com/itm/5V-2-5A-D-Li...3 01720248001
....

Bottom line...buy the new supply.


I did that. Should be here on Friday.

In the same way that planning for a vacation is almost as much fun as
the vacation, it seems yesterday planning to repair the PS was 1/3rd
the fun of actually doing it, plus I don't have a zener diode and even
the parts I do have become a little hard to find.

Problem with that one is the plug on the end is different from
most other router power supplies. Get the right one and be done with it.


They have the exact one, with the green plug showing in the photo.

I fix wall warts all the time for my own use. I'd never sell a gizmo
with a power supply that I repaired. Too much liability involved.

Most fail with shorted input diodes, but
that also blows the fuse.
I've been fixing stuff for almost half a century, but working on
line-connected
stuff still scares the hell out of me...and I've got a completely isolated
scope probe system.
Even if you do find out what's broke, where are you gonna get the
replacement part?
Putting it back together is problematic. What happens if you
try to unplug it and the glue breaks...you end up with AC in your
hands...not fun.

Look at the risk/reward ratio.
Best that can possibly happen is you save $7.50.
Worst is electrocution? burning down your house?
For stuff connected directly to the line,
if you don't know what you're doing, keep it that way.


If I did it, I'd do it right. I know what I'm doing. Not knowing which
part to replace doesn't mean I don't know what I'm doing.
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Default How to fix my 5V, 2.5amp adapter.

In article , NONONOmisc07
@bigfoot.com says...

On Sat, 21 Nov 2015 13:19:22 -0500, M Philbrook
wrote:

In article ,
says...

On Fri, 20 Nov 2015 18:26:39 -0500, M Philbrook
wrote:

Its amazing how you guys can find schematics to these things.

It's actually quite easy. Instead of searching the web, I do an image
search. Photos, schematics, disassembly instructions, and such are
much easier to find using images than text. You can text search for
"xxxxx schematic" but schematics are rarely titles with the word
"schematic" on the page.

If the photo is not quite what I want, such as Google image search
find a thumbnail instead of a full size image, I use one of several
reverse image searches to find the original:
https://support.google.com/websearch/answer/1325808?hl=en
https://www.tineye.com
etc...


I'll keep that in mind, Thanks

Jamie


Me too. Thanks.

One more question.

If I couldnt' find a power supply for the router, until I bought a new
one, could I have just unplugged the wire from the DSL modem to the
router and plugged it into the computer? The only thing I'm doing
wirelessly now is print, and I don't print very often.

This idea kept popping in my head and then disappearing.


No, you do not want to power off the USB port of the computer.

that supply is over 2 amps and most likely for good reason.

My router requires 1 amp minimum while the USB ports on most
PC's are 500mA (1/2 amp)

You can have a USB port that has charging options, and also they
do come with higher current but that is not the norm.

USB 3.x for the most part I understand have more powwer.

You are better off not chancing it.

Jamie.

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"Micky" wrote in message
...

If I couldnt' find a power supply for the router, until I bought a new
one, could I have just unplugged the wire from the DSL modem to the
router and plugged it into the computer? The only thing I'm doing
wirelessly now is print, and I don't print very often.

This idea kept popping in my head and then disappearing.


If you are talking about using the data cable and removing the router from
the system, you should be able to do it with out any problems. I do it from
time to time just to check the download and upload speeds.


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It's a very common failure on supplies that run 24/7 to fail to restart after a cool down period.

Get any old hair dryer and give it a nice sauna for a few minutes, then plug it back in. If it starts, it's a high ESR cap in about 95% of the time.


On Saturday, November 21, 2015 at 3:26:29 PM UTC-5, Micky wrote:
On Fri, 20 Nov 2015 09:50:15 -0800, mike wrote:

On 11/20/2015 12:43 AM, Micky wrote:
How to fix my 5V, 2.5amp adapter.

I had 4 short power failures today, and everything on the PC started
up fine after the first 3. The fourth was longer so I went grocery
shopping.

When I restarted, none of the lights on the wireless router went on,
and an ohmmeter showed infinite resistance between the two prongs that
plug into the wall. I had a surge, didn't I?


Apparently it just cooled off!


P. S. This is what's broken:
http://www.ebay.com/itm/5V-2-5A-D-Li...3 01720248001
....

Bottom line...buy the new supply.


I did that. Should be here on Friday.

In the same way that planning for a vacation is almost as much fun as
the vacation, it seems yesterday planning to repair the PS was 1/3rd
the fun of actually doing it, plus I don't have a zener diode and even
the parts I do have become a little hard to find.

Problem with that one is the plug on the end is different from
most other router power supplies. Get the right one and be done with it..


They have the exact one, with the green plug showing in the photo.

I fix wall warts all the time for my own use. I'd never sell a gizmo
with a power supply that I repaired. Too much liability involved.

Most fail with shorted input diodes, but
that also blows the fuse.
I've been fixing stuff for almost half a century, but working on
line-connected
stuff still scares the hell out of me...and I've got a completely isolated
scope probe system.
Even if you do find out what's broke, where are you gonna get the
replacement part?
Putting it back together is problematic. What happens if you
try to unplug it and the glue breaks...you end up with AC in your
hands...not fun.

Look at the risk/reward ratio.
Best that can possibly happen is you save $7.50.
Worst is electrocution? burning down your house?
For stuff connected directly to the line,
if you don't know what you're doing, keep it that way.


If I did it, I'd do it right. I know what I'm doing. Not knowing which
part to replace doesn't mean I don't know what I'm doing.


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Default How to fix my 5V, 2.5amp adapter.

On Sat, 21 Nov 2015 15:19:59 -0500, Micky
wrote:

If I couldnt' find a power supply for the router, until I bought a new
one, could I have just unplugged the wire from the DSL modem to the
router and plugged it into the computer? The only thing I'm doing
wirelessly now is print, and I don't print very often.


Yes. 5V from the computer is the same as 5v from the Dlink wall wart.


No, no 5v at all. I mean eliminating the router and going straight
from the DSL modem to the network card in the computer. That's the
default, isn't it? It's only been 8 years but I can't remember.


That will work if:
1. If you're using PPPoE or PPPoA that require a login and password,
it will work if those are saved in the DSL modem or in the computah.
However, if you saved them in the router, you'll have to temporarily
move them.
2. If you trust your unspecified operating system to be secure
without the hardware firewall in the router. The DSL modem passes all
ports, even if it has internal DHCP, so your computah's firewall does
all the work.
3. If your DSL modem is independent of your router and doesn't
require a hack saw to seperate them.

Can't you find a 5V power source and a power jack and do it correctly?
This is a repair newsgroup, not a substitution newsgroup. A 5v 2A
cell phone or tablet charger should work. Worst case is borrow the 5V
from the PC. Do something, even if it's wrong.


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


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Default How to fix my 5V, 2.5amp adapter.

On Sat, 21 Nov 2015 20:12:59 -0000, MJC
wrote:

In article ,
says...

It's actually quite easy. Instead of searching the web, I do an image
search. Photos, schematics, disassembly instructions, and such are
much easier to find using images than text.


Sorry, I still don't follow: what are you using as your search
criterion? I see how you might get disassembly instructions (or lots of
sales pitches!) using a photo of the outside of the device, but
schematics?

Mike.


Ok, I'll walk you through it. First, I do a web search by product
name and buzzword:
https://www.google.com/#q=d+link+JTA0302+repair
The first hit is the page I posted, which is more luck than finesse.
However, we're looking for a schematic, so I click on the "Images"
button for:
https://www.google.com/search?q=d+link+JTA0302+repair&tbm=isch
(Edited and shortened for clarity). Notice that several schematics
magically appear in the results.

Let's pretend that you don't see the schematic that you're looking
for. Click on ANY schematic. The search results will display the
image with "Visit Page" and "View Image" button. However, we're gonna
do something different. In the lower right are a series of thumbnails
one of which is labeled "View More". Click that and you have pages
and pages of similar schematics to sift through.
https://www.google.com/search?q=d+link+JTA0302+repair&biw=1397&bih=821&so urce=lnms&tbm=isch&sa=X&ved=0ahUKEwinr4_vy6LJAhUP8 GMKHdV9COMQ_AUICSgE#tbm=isch&tbs=rimg%3ACZFH9IV11d HBIjg-oc7iGryprYGhMbJL3yU7s4yBEMwNeVqVguPgWuTPn2TyHae7nb kM1unm89X-59h8DZFv_1RHtmyoSCT6hzuIavKmtEVcoqqCFxshoKhIJgaExs kvfJTsRfsuryv7U1zsqEgmzjIEQzA15WhH4nOkQgb56QyoSCZW C4-Ba5M-fET10TFIWWvIdKhIJZPIdp7uduQwR1e6tkiviKPIqEgnW6ebz1 f7n2BETj_1Q1PRiNPCoSCXwNkW_19Ee2bEXI-6EAgeQ1c&q=d%20link%20JTA0302%20repair
Here's one in Russian that looks interesting:
http://masterpaiki.ru/goryachaya-shtuchka-d-link-ili-chinim-bp-jta0303e-e.html
Use Google Translate to convert it to English.
https://support.google.com/chrome/answer/173424?hl=en

In case you haven't noticed, it really doesn't matter exactly what you
use for a search. At a minimum, the model number. Notice that I
chopped off the version suffix letter from the model number. Instead
of "repair", you could use inside, schematic, disassemble, tear apart,
bulging capacitor, etc. Whatever works to bring up images that are
close. Your eyes do the rest.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default How to fix my 5V, 2.5amp adapter.

On Sat, 21 Nov 2015 14:43:57 -0800, Jeff Liebermann
wrote:

On Sat, 21 Nov 2015 15:19:59 -0500, Micky
wrote:

If I couldnt' find a power supply for the router, until I bought a new
one, could I have just unplugged the wire from the DSL modem to the
router and plugged it into the computer? The only thing I'm doing
wirelessly now is print, and I don't print very often.

Yes. 5V from the computer is the same as 5v from the Dlink wall wart.


No, no 5v at all. I mean eliminating the router and going straight
from the DSL modem to the network card in the computer. That's the
default, isn't it? It's only been 8 years but I can't remember.


That will work if:
1. If you're using PPPoE or PPPoA that require a login and password,
it will work if those are saved in the DSL modem or in the computah.
However, if you saved them in the router, you'll have to temporarily
move them.
2. If you trust your unspecified operating system to be secure
without the hardware firewall in the router. The DSL modem passes all
ports, even if it has internal DHCP, so your computah's firewall does
all the work.
3. If your DSL modem is independent of your router and doesn't
require a hack saw to seperate them.

Can't you find a 5V power source and a power jack and do it correctly?


I did already. It was just a question.

This is a repair newsgroup, not a substitution newsgroup. A 5v 2A
cell phone or tablet charger should work. Worst case is borrow the 5V
from the PC.


You mean USB, or something on the mobo? I'd have to fix up a cable
to do that.

Do something, even if it's wrong.

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Default How to fix my 5V, 2.5amp adapter.

On Sat, 21 Nov 2015 17:04:20 -0500, "Ralph Mowery"
wrote:


"Micky" wrote in message
.. .

If I couldnt' find a power supply for the router, until I bought a new
one, could I have just unplugged the wire from the DSL modem to the
router and plugged it into the computer? The only thing I'm doing
wirelessly now is print, and I don't print very often.

This idea kept popping in my head and then disappearing.


If you are talking about using the data cable and removing the router from
the system, you should be able to do it with out any problems. I do it from
time to time just to check the download and upload speeds.


Good. It looks like "wire" was too vague a term. Two people
thought I meant the power wire (because that's what we'd been talking
about) and even you asked if really meant the data cable. Sorry.

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Default How to fix my 5V, 2.5amp adapter.

On Sat, 21 Nov 2015 14:18:35 -0800 (PST), John-Del
wrote:

It's a very common failure on supplies that run 24/7 to fail to restart after a cool down period.

Get any old hair dryer and give it a nice sauna for a few minutes, then plug it back in. If it starts, it's a high ESR cap in about 95% of the time.


Aha. I saved a hair dryer I got somewhere just for testing
electronics, but I had in mind testing for things that do NOT work
when they're hot. I'll remember to test for those that work when they
ARE hot. I could test this very PSU...oh, that's what you meant. (I
thought you were giving general advice.)

I'll dig out the hair dryer and do that.

In ESR cap, what does ESR mean?

On Saturday, November 21, 2015 at 3:26:29 PM UTC-5, Micky wrote:
On Fri, 20 Nov 2015 09:50:15 -0800, mike wrote:

On 11/20/2015 12:43 AM, Micky wrote:
How to fix my 5V, 2.5amp adapter.

I had 4 short power failures today, and everything on the PC started
up fine after the first 3. The fourth was longer so I went grocery
shopping.

When I restarted, none of the lights on the wireless router went on,
and an ohmmeter showed infinite resistance between the two prongs that
plug into the wall. I had a surge, didn't I?


Apparently it just cooled off!


P. S. This is what's broken:
http://www.ebay.com/itm/5V-2-5A-D-Li...3 01720248001
....

Bottom line...buy the new supply.


I did that. Should be here on Friday.

In the same way that planning for a vacation is almost as much fun as
the vacation, it seems yesterday planning to repair the PS was 1/3rd
the fun of actually doing it, plus I don't have a zener diode and even
the parts I do have become a little hard to find.

Problem with that one is the plug on the end is different from
most other router power supplies. Get the right one and be done with it.


They have the exact one, with the green plug showing in the photo.

I fix wall warts all the time for my own use. I'd never sell a gizmo
with a power supply that I repaired. Too much liability involved.

Most fail with shorted input diodes, but
that also blows the fuse.
I've been fixing stuff for almost half a century, but working on
line-connected
stuff still scares the hell out of me...and I've got a completely isolated
scope probe system.
Even if you do find out what's broke, where are you gonna get the
replacement part?
Putting it back together is problematic. What happens if you
try to unplug it and the glue breaks...you end up with AC in your
hands...not fun.

Look at the risk/reward ratio.
Best that can possibly happen is you save $7.50.
Worst is electrocution? burning down your house?
For stuff connected directly to the line,
if you don't know what you're doing, keep it that way.


If I did it, I'd do it right. I know what I'm doing. Not knowing which
part to replace doesn't mean I don't know what I'm doing.

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Default How to fix my 5V, 2.5amp adapter.


"Micky" wrote in message
...

In ESR cap, what does ESR mean?

Look up equivilent series resistance. In short it is a number that tells of
the quality of the capacitor especially when used in switching and high
frequency circuits.

Most any old capacitor will be ok for filtering out 60 hz in the old power
supplies. When the switchers came out , the capacitors begain to fail .
Checking on a simple capacitor meter will show the value ok, but they fail
under the high speed/frequency high current usage.




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Default How to fix my 5V, 2.5amp adapter.

Ralph Mowery wrote:

In ESR cap, what does ESR mean?

Look up equivilent series resistance. In short it is a number that tells of
the quality of the capacitor especially when used in switching and high
frequency circuits.

Most any old capacitor will be ok for filtering out 60 hz in the old power
supplies. When the switchers came out , the capacitors begain to fail .
Checking on a simple capacitor meter will show the value ok, but they fail
under the high speed/frequency high current usage.


** The ESR of an electro cap is mostly due to the conductivity of the liquid electrolyte used inside.

Modern, water based electrolytes have much better conductivity and hence lower ESR values compared to the same size caps made in the past and so can handle higher operating currents without excessive self heating.

Heat is the main killer of electros, whether from the local ambient temp or current flow in the cap or both. Luckily, the conductance of electrolytes improves with increasing temp which helps extend their life in SMPS.


.... Phil
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Default How to fix my 5V, 2.5amp adapter.

On Sat, 21 Nov 2015 21:20:02 -0800 (PST), Phil Allison
wrote:

Ralph Mowery wrote:

In ESR cap, what does ESR mean?

Look up equivilent series resistance. In short it is a number that tells of
the quality of the capacitor especially when used in switching and high
frequency circuits.

Most any old capacitor will be ok for filtering out 60 hz in the old power
supplies. When the switchers came out , the capacitors begain to fail .
Checking on a simple capacitor meter will show the value ok, but they fail
under the high speed/frequency high current usage.

.
** The ESR of an electro cap is mostly due to the conductivity of the liquid electrolyte used inside.

Modern, water based electrolytes have much better conductivity and hence lower ESR values compared to the same size caps made in the past and so can handle higher operating currents without excessive self heating.

Heat is the main killer of electros, whether from the local ambient temp or current flow in the cap or both. Luckily, the conductance of electrolytes improves with increasing temp which helps extend their life in SMPS.


Thank you both.

... Phil

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If you have a dead open at the AC input,
It could also be an open srge current limiter,
thats the device in series w the fuse.
It's supposed to be a high resistance when
cold and change gradually to a low resistance
As it heats.
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Phil Allison wrote:

** The ESR of an electro cap is mostly due to the conductivity of the
liquid electrolyte used inside.

Modern, water based electrolytes have much better conductivity and
hence lower ESR values compared to the same size caps made in the
past and so can handle higher operating currents without excessive
self heating.


What time frame do you mean by "modern" as opposed to "past?"

When motherboard caps fail long after the "plague" was over, is it
mainly due to the voltage being under-rated?


Heat is the main killer of electros, whether from the local ambient
temp or current flow in the cap or both. Luckily, the conductance of
electrolytes improves with increasing temp which helps extend their
life in SMPS.


... Phil


--


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