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 Fuse size in IBM ThinkPad T22 wallwart power supply

The power supply that goes to the IBM ThinkPad T22 got wet!

arcing sounds, zsst! does not work now. Internally found a blown
pigtail fuse. plus, [and this does NOT bode well] blackened PCB areas
around AC mains traces.

The pigtail fuse does not appear to be simple physical caps going over
the 8AG type but solidly attached to the metal end caps. Plus, and
this ALWAYS happens, the value is UNDER the fuse body and is not
accessible. I'd like to simply put asimilarly rated fuse in parallel
to check if the problem is only the fuse, but don't know the amperage.

Anybody know the rating? The main unit is in the range of 16V 3.36A
so the fuse could be 1 to 2A, but the wire laying down inside looks
heavier. Maybe the fuse is in series with the output ? and is more
like 5 to 10A ??

Anybody have a manual, or URL to find out?

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Default Fuse size in IBM ThinkPad T22 wallwart power supply



"Robert Macy" wrote in message
...
The power supply that goes to the IBM ThinkPad T22 got wet!

arcing sounds, zsst! does not work now. Internally found a blown
pigtail fuse. plus, [and this does NOT bode well] blackened PCB areas
around AC mains traces.

The pigtail fuse does not appear to be simple physical caps going over
the 8AG type but solidly attached to the metal end caps. Plus, and
this ALWAYS happens, the value is UNDER the fuse body and is not
accessible. I'd like to simply put asimilarly rated fuse in parallel
to check if the problem is only the fuse, but don't know the amperage.

Anybody know the rating? The main unit is in the range of 16V 3.36A
so the fuse could be 1 to 2A, but the wire laying down inside looks
heavier. Maybe the fuse is in series with the output ? and is more
like 5 to 10A ??

Anybody have a manual, or URL to find out?


It'll be a switcher. If it got wet, and the input fuse is blown, and the
board is blackened, it can probably be pretty much considered to be beyond
resurrection ...

I'd feel inclined to clean up the blackened bit as best you can, and then
hang a 1 amp fuse across the original. If that immediately blows, it's not
going to be worth wasting more time on.

Arfa

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Default Fuse size in IBM ThinkPad T22 wallwart power supply

Robert Macy wrote:

The power supply that goes to the IBM ThinkPad T22 got wet!

arcing sounds, zsst! does not work now. Internally found a blown
pigtail fuse. plus, [and this does NOT bode well] blackened PCB areas
around AC mains traces.

The pigtail fuse does not appear to be simple physical caps going over
the 8AG type but solidly attached to the metal end caps. Plus, and
this ALWAYS happens, the value is UNDER the fuse body and is not
accessible. I'd like to simply put asimilarly rated fuse in parallel
to check if the problem is only the fuse, but don't know the amperage.

Anybody know the rating? The main unit is in the range of 16V 3.36A
so the fuse could be 1 to 2A, but the wire laying down inside looks
heavier. Maybe the fuse is in series with the output ? and is more
like 5 to 10A ??

Anybody have a manual, or URL to find out?

Attach a 55 watt incandescent lamp across the open fuse and use that as
the test fuse.

And if you don't understand how that would work for you, you shouldn't
be doing none of this, at all.


Jamie



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Default Fuse size in IBM ThinkPad T22 wallwart power supply


Robert Macy wrote:

The power supply that goes to the IBM ThinkPad T22 got wet!

arcing sounds, zsst! does not work now. Internally found a blown
pigtail fuse. plus, [and this does NOT bode well] blackened PCB areas
around AC mains traces.

The pigtail fuse does not appear to be simple physical caps going over
the 8AG type but solidly attached to the metal end caps. Plus, and
this ALWAYS happens, the value is UNDER the fuse body and is not
accessible. I'd like to simply put asimilarly rated fuse in parallel
to check if the problem is only the fuse, but don't know the amperage.

Anybody know the rating? The main unit is in the range of 16V 3.36A
so the fuse could be 1 to 2A, but the wire laying down inside looks
heavier. Maybe the fuse is in series with the output ? and is more
like 5 to 10A ??

Anybody have a manual, or URL to find out?



You can get new power supply on Ebay for $8.

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p5197.m570.l1313&_nkw=IBM +ThinkPad+T22+power+supply&_sacat=See-All-Categories


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Default Fuse size in IBM ThinkPad T22 wallwart power supply

On Mon, 31 Oct 2011 17:34:12 -0700 (PDT), Robert Macy
wrote:

The power supply that goes to the IBM ThinkPad T22 got wet!


I don't think there's a fuse inside. Dry it out as best you can. Give
it about a week or two in a warm area. Then, try it again. Otherwise,
just buy another power supply on eBay.
http://www.ebay.com/sch/i.html?_nkw=thinkpad+t22+power+supply
--
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# 831-336-2558
# http://802.11junk.com
#
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Default Fuse size in IBM ThinkPad T22 wallwart power supply

On Oct 31, 6:41*pm, Jamie
t wrote:
Robert Macy wrote:
The power supply that goes to the IBM ThinkPad T22 got wet!


arcing sounds, zsst! does not work now. Internally found a blown
pigtail fuse. *plus, [and this does NOT bode well] blackened PCB areas
around AC mains traces.


The pigtail fuse does not appear to be simple physical caps going over
the 8AG type but solidly attached to the metal end caps. *Plus, and
this ALWAYS happens, the value is UNDER the fuse body and is not
accessible. *I'd like to simply put asimilarly rated fuse in parallel
to check if the problem is only the fuse, but don't know the amperage.


Anybody know the rating? * *The main unit is in the range of 16V 3.36A
so the fuse could be 1 to 2A, but the wire laying down inside looks
heavier. *Maybe the fuse is in series with the output ? and is more
like 5 to 10A ??


Anybody have a manual, or URL to find out?


Attach a 55 watt incandescent lamp across the open fuse and use that as
the test fuse.

* *And if you don't understand how that would work for you, you shouldn't
be doing none of this, at all.

* Jamie


Forgot about using a lamp as a fuse replacement to limit the current.
Or heater for higher current

Didn't know they made 55W bulbs, found 60W and 40W and one that
switches 50-100-150, but no 55W

Hmmm....that's about 260 ohm HOT, when cold more like 26 ohms. so the
current will go somewhere between 5A down to 0.5A

still safer than putting in a 'penny'
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Default Fuse size in IBM ThinkPad T22 wallwart power supply

On Oct 31, 7:28*pm, "Michael A. Terrell"
wrote:
Robert Macy wrote:

The power supply that goes to the IBM ThinkPad T22 got wet!


arcing sounds, zsst! does not work now. Internally found a blown
pigtail fuse. *plus, [and this does NOT bode well] blackened PCB areas
around AC mains traces.


The pigtail fuse does not appear to be simple physical caps going over
the 8AG type but solidly attached to the metal end caps. *Plus, and
this ALWAYS happens, the value is UNDER the fuse body and is not
accessible. *I'd like to simply put asimilarly rated fuse in parallel
to check if the problem is only the fuse, but don't know the amperage.


Anybody know the rating? * *The main unit is in the range of 16V 3.36A
so the fuse could be 1 to 2A, but the wire laying down inside looks
heavier. *Maybe the fuse is in series with the output ? and is more
like 5 to 10A ??


Anybody have a manual, or URL to find out?


* *You can get new power supply on Ebay for $8.

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p5197.m570.l1313&_nk...

--
You can't have a sense of humor, if you have no sense.


thank you for the URL. Any experience with any of these suppliers?
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Default Fuse size in IBM ThinkPad T22 wallwart power supply

On Oct 31, 8:19*pm, Jeff Liebermann wrote:
On Mon, 31 Oct 2011 17:34:12 -0700 (PDT), Robert Macy

wrote:
The power supply that goes to the IBM ThinkPad T22 got wet!


I don't think there's a fuse inside. *Dry it out as best you can. Give
it about a week or two in a warm area. *Then, try it again. Otherwise,
just buy another power supply on eBay.
http://www.ebay.com/sch/i.html?_nkw=thinkpad+t22+power+supply
--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
#http://802.11junk.com* * * * * * *
#http://www.LearnByDestroying.com* * * * * * * AE6KS


thank you for the URL, I'm not familiar with using eBay, especially
since I avoid eBay like the plague.

but this time, ....any experiences with any of these suppliers?

Yes, there is a pigtail fuse inside. just can't read the value on the
UNDERSIDE!

Don't even want to start taking it apart if the rest is dead.

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Default Fuse size in IBM ThinkPad T22 wallwart power supply


Robert Macy wrote:

On Oct 31, 7:28 pm, "Michael A. Terrell"
wrote:
Robert Macy wrote:

The power supply that goes to the IBM ThinkPad T22 got wet!


arcing sounds, zsst! does not work now. Internally found a blown
pigtail fuse. plus, [and this does NOT bode well] blackened PCB areas
around AC mains traces.


The pigtail fuse does not appear to be simple physical caps going over
the 8AG type but solidly attached to the metal end caps. Plus, and
this ALWAYS happens, the value is UNDER the fuse body and is not
accessible. I'd like to simply put asimilarly rated fuse in parallel
to check if the problem is only the fuse, but don't know the amperage.


Anybody know the rating? The main unit is in the range of 16V 3.36A
so the fuse could be 1 to 2A, but the wire laying down inside looks
heavier. Maybe the fuse is in series with the output ? and is more
like 5 to 10A ??


Anybody have a manual, or URL to find out?


You can get new power supply on Ebay for $8.

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p5197.m570.l1313&_nk...


thank you for the URL. Any experience with any of these suppliers?



I've bought about a dozen laptop power supplies on Ebay, but can't
remember the vendors names. They work well on the computers I bought
them for.


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Default Fuse size in IBM ThinkPad T22 wallwart power supply

On Oct 31, 7:28*pm, "Michael A. Terrell"
wrote:
Robert Macy wrote:

The power supply that goes to the IBM ThinkPad T22 got wet!


arcing sounds, zsst! does not work now. Internally found a blown
pigtail fuse. *plus, [and this does NOT bode well] blackened PCB areas
around AC mains traces.


The pigtail fuse does not appear to be simple physical caps going over
the 8AG type but solidly attached to the metal end caps. *Plus, and
this ALWAYS happens, the value is UNDER the fuse body and is not
accessible. *I'd like to simply put asimilarly rated fuse in parallel
to check if the problem is only the fuse, but don't know the amperage.


Anybody know the rating? * *The main unit is in the range of 16V 3.36A
so the fuse could be 1 to 2A, but the wire laying down inside looks
heavier. *Maybe the fuse is in series with the output ? and is more
like 5 to 10A ??


Anybody have a manual, or URL to find out?


* *You can get new power supply on Ebay for $8.

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p5197.m570.l1313&_nk...

--
You can't have a sense of humor, if you have no sense.


Thank you, that's the FIRST time I've bought on eBay.

Cost 8.95 total cost, very prompt arrival with their expenditure for
shipping 3.28 !! labeled made in China, does NOT have the AC plugged
in LED, but at these prices, I can live without it.

Seems to work, the laptop display is still defunct.


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Default Fuse size in IBM ThinkPad T22 wallwart power supply



"Robert Macy" wrote in message
...
On Oct 31, 7:28 pm, "Michael A. Terrell"
wrote:
Robert Macy wrote:

The power supply that goes to the IBM ThinkPad T22 got wet!


arcing sounds, zsst! does not work now. Internally found a blown
pigtail fuse. plus, [and this does NOT bode well] blackened PCB areas
around AC mains traces.


The pigtail fuse does not appear to be simple physical caps going over
the 8AG type but solidly attached to the metal end caps. Plus, and
this ALWAYS happens, the value is UNDER the fuse body and is not
accessible. I'd like to simply put asimilarly rated fuse in parallel
to check if the problem is only the fuse, but don't know the amperage.


Anybody know the rating? The main unit is in the range of 16V 3.36A
so the fuse could be 1 to 2A, but the wire laying down inside looks
heavier. Maybe the fuse is in series with the output ? and is more
like 5 to 10A ??


Anybody have a manual, or URL to find out?


You can get new power supply on Ebay for $8.

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p5197.m570.l1313&_nk...

--
You can't have a sense of humor, if you have no sense.


Thank you, that's the FIRST time I've bought on eBay.

Cost 8.95 total cost, very prompt arrival with their expenditure for
shipping 3.28 !! labeled made in China, does NOT have the AC plugged
in LED, but at these prices, I can live without it.

Seems to work, the laptop display is still defunct.


I buy from eBay all the time. I often find that components that I can't
source from my regular mainstream suppliers, are readily available from eBay
shops. Sometimes, you wait a few days when the 'shop' is in China or
Singapore or wherever, but it's worth living with that to be able to get the
bits. I can honestly say that I've never had a problem with any item that
I've bought. A couple of weeks back, my HP printer was showing that the
yellow ink had run out - again - and was refusing to print in colour as a
result. The cartridges are about 7 UKP a pop, and there are six of the
buggers. The 'high capacity' black, which still contains pitifully little
ink, is even more expensive. A few months back, I needed a couple of
colours, and the local store had run out of them both, so I did what I have
never dared do before, and bought a couple of no-brand compatibles from a
printer ink shop in the town. They weren't actually very much cheaper than
the real thing, but I have to say that they did work ok.

So when the yellow ran out again last week, I decided to have a look on
eBay. I found a UK shop located up in the northeast, selling a kit of 12 -
yes that's twelve! - cartridges, for 7.99 UKP total (!!) with free postage
!! I had to read it several times. Not only is this two complete sets, the
colour ones are 18 ml content, and the black is a 45 ml. The blurb says that
they are guaranteed for 12 months, and are fitted with the 'high capacity'
identifier chip.

I ordered them at 2am. By 8am, they were showing as 'shipped', and they
arrived in the post first thing the next morning. Each cartridge is
individually vacuum wrapped. For sure, there is a lot of Chinese writing on
the packets, so I guess that's where they come from, but hey, who cares ?
Not me, that's for sure. Anyway, I put the yellow in, and the machine
accepted it without question, and has indeed registered it correctly as a
high capacity cartridge. So far, it has performed faultlessly. The dark
magenta started to issue warnings that it was getting low today, so I guess
that will be the next one to go in.

I think that as long as you are sensible with eBay dealings, and take note
of the feedback that's been given to a seller by his customers, there's no
need to fear using it, at all.

Arfa

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Default Fuse size in IBM ThinkPad T22 wallwart power supply

On Thu, 17 Nov 2011 13:45:42 -0800 (PST), Robert Macy
wrote:

The laptop boots up, beeps because the date is set to 1981 [can't see
the screen, backlight is OUT, just know the significance of the beep]
Conclusion SMPS works, laptop basically works. just no screen!


Plug in an external monitor into the "VGA" connector.

So following the T22 manual dissassembled down to the LCD screen,
could not see anything that looked like liquid and dried salts, so
don't know what's still wrong. Flushed with distilled water anywy and
will let dry. Will see later if that brings it back.


Sigh. When the laptop recovers from the baptism, turn it on, and
shine a flashlight on the screen. Can you see the image of whatever
it's booting? You may need to move the flashlight around to see the
image. If it's visible, it's probably the inverter. However, if it
comes on with an orange glow, it's the CCFL lamps in the LCD panel.

Is the 'inverter card' the ps for the backlight?


Yep. Google for "Thinkpad T22 LCD Inverter".
www.ebay.com/sch/i.html?_nkw=thinkpad+t22+lcd+inverter
About $6.00

is it touchy and blows easily?


Yep. If you short it out with salt water and it can blow up. High
voltage does funny things to sensitive electronics.

If I can find a way to remove the cap covers over the screws without
destroying the cap covers,


The screw covers are made from sheet plastic and held in with rubber
cement. Pound a very small flat screwdriver between the screw cover
and the plastic frame, and pry upward.

I'll take out the invreter board and look
at it to see if any obvious damage. Or ohm out the terminals on the
main switching transistor to see if it got toasted. Any ideas?


Find an AC voltmeter and measure the output voltage. For laptops, my
guess(tm) is about 500-800 VAC. Please remember that you have but one
life to give for your laptop.

Incidentally, the fan is often a problem on such Thinkpad laptops.


--
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 Fuse size in IBM ThinkPad T22 wallwart power supply

On Nov 17, 10:55*pm, Jeff Liebermann wrote:
On Thu, 17 Nov 2011 13:45:42 -0800 (PST), Robert Macy

wrote:
The laptop boots up, beeps because the date is set to 1981 [can't see
the screen, backlight is OUT, just know the significance of the beep]
Conclusion SMPS works, laptop basically works. just no screen!


Plug in an external monitor into the "VGA" connector.

So following the T22 manual dissassembled down to the LCD screen,
could not see anything that looked like liquid and dried salts, so
don't know what's still wrong. *Flushed with distilled water anywy and
will let dry. Will see later if that brings it back.


Sigh. *When the laptop recovers from the baptism, turn it on, and
shine a flashlight on the screen. *Can you see the image of whatever
it's booting? *You may need to move the flashlight around to see the
image. *If it's visible, it's probably the inverter. *However, if it
comes on with an orange glow, it's the CCFL lamps in the LCD panel.

Is the 'inverter card' the ps for the backlight?


Yep. *Google for "Thinkpad T22 LCD Inverter".
www.ebay.com/sch/i.html?_nkw=thinkpad+t22+lcd+inverter
About $6.00

is it touchy and blows easily?


Yep. *If you short it out with salt water and it can blow up. *High
voltage does funny things to sensitive electronics.

If I can find a way to remove the cap covers over the screws without
destroying the cap covers,


The screw covers are made from sheet plastic and held in with rubber
cement. *Pound a very small flat screwdriver between the screw cover
and the plastic frame, and pry upward.

I'll take out the invreter board and look
at it to see if any obvious damage. *Or ohm out the terminals on the
main switching transistor to see if it got toasted. *Any ideas?


Find an AC voltmeter and measure the output voltage. *For laptops, my
guess(tm) is about 500-800 VAC. *Please remember that you have but one
life to give for your laptop.

Incidentally, the fan is often a problem on such Thinkpad laptops.

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


Jeff,

Thank you for the URL to eBay. The inverter PCB was identically
labeled to the one I removed and only cost $5, however, upon re-
assembly the screen is still dark.


Where it stands now:

The Laptop when connected to an external monitor, a C500 Multisync,
came right up recognized the new monitor put in drivers and was
displaying normally. Conclusion, the HD, the CPU works! so all is not
lost.

The USB port did NOT work for a very long time but multiple insertions
seem to have awakened that port. Hmmmm, wonder if it is still
'corroded' connectors to the buillt in display.

Anyway, I tried a flashlight near the LCD screen and could see
nothing, no changings, like I expected something to be viewable.
Maybe stronger light?. not sure the screen is being updated at all.


Culmination, so far is my first two experiences with eBay have been
excellent. Prompt shipment, with tracking numbers, sadly, USPS
screwed up badly and I did not receive the $5 Inverter PCB for almost
a month! Plus, the shipping company had to resend at their expense!
just not right.

Any suggestions for the next step?
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Default Fuse size in IBM ThinkPad T22 wallwart power supply

Robert Macy wrote:

(...)

Any suggestions for the next step?


How far did you get with:
*Also see p. 54 for LCD troubleshooting tips.*
http://download.lenovo.com/ibmdl/pub...df/62p9631.pdf

?

--Winston
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Default Fuse size in IBM ThinkPad T22 wallwart power supply

On Thu, 15 Dec 2011 17:28:06 -0800 (PST), Robert Macy
wrote:

On Nov 17, 10:55*pm, Jeff Liebermann wrote:


Find an AC voltmeter and measure the output voltage. *For laptops, my
guess(tm) is about 500-800 VAC. *Please remember that you have but one
life to give for your laptop.


Thank you for the URL to eBay. The inverter PCB was identically
labeled to the one I removed and only cost $5, however, upon re-
assembly the screen is still dark.


Measure the inverter output voltage as above.

Make sure you don't have the keyboard video switch set for
external monitor only. On the T22 it's Fn-F7. Hold down
the Fn button, and tap the F7 button *ONCE*. Anything on
the screen? If not, tap the F7 button again.

Check the CMOS setup and make sure that the default display
is the internal LCD display, and not the external.

I've received blown LCD inverters in the past. That's why I
always buy two inverters. That's the risks of buying used
parts extracted from allegedly working units.

Remove the keyboard and look for the video connector. It's
a big fat cable coming from the left hinge and ending up on
the motherboard. Make sure the connector is properly seated.

Check the backlighting display settings in the Thinkpad
hardware manager application (I forgot what it's called).
On some versions, it's possible to set the display brightness
(also known as backlighting) to zero.

I have spare displays, but I don't think that's an option for
you to try.

Anyway, I tried a flashlight near the LCD screen and could see
nothing, no changings, like I expected something to be viewable.
Maybe stronger light?. not sure the screen is being updated at all.


It's difficult to see. Humor me and start over. Shut off the
laptop. Remove the AC power supply. Unplug the battery. Go away
for about 15 minutes to make sure everything is reset. Do *NOT*
attach the external monitor. Put everything back and turn on the
machine. Do NOT play with Fn-F7. Now, try the flashlight trick.

Culmination, so far is my first two experiences with eBay have been
excellent. Prompt shipment, with tracking numbers, sadly, USPS
screwed up badly and I did not receive the $5 Inverter PCB for almost
a month! Plus, the shipping company had to resend at their expense!
just not right.


I've had plenty of problems with USPS over the years. The other
carriers are usually much better. Be sure to complain to the USPS and
mention that they only have online delivery notification, not
tracking, making it difficult to find lost packages.

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


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On Thu, 15 Dec 2011 20:02:59 -0800, Jeff Liebermann
wrote:

Remove the keyboard and look for the video connector. It's
a big fat cable coming from the left hinge and ending up on
the motherboard. Make sure the connector is properly seated.


Oops. Wrong description. It's a flat ribbon cable with the connector
located about 1" from the rear center of the laptop on the
motherboard.



--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com
#
http://www.LearnByDestroying.com AE6KS
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Default Fuse size in IBM ThinkPad T22 wallwart power supply

On Dec 15, 9:12*pm, Jeff Liebermann wrote:
On Thu, 15 Dec 2011 20:02:59 -0800, Jeff Liebermann
wrote:

Remove the keyboard and look for the video connector. *It's
a big fat cable coming from the left hinge and ending up on
the motherboard. *Make sure the connector is properly seated.


Oops. *Wrong description. *It's a flat ribbon cable with the connector
located about 1" from the rear center of the laptop on the
motherboard.

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


FINALLY!! I verified that the LCD screen is validly changing pixels,
all I need is the backlight.

Measure voltage. If the tube is OFF, is that the firing voltage?
trying to get the tube to arc? sounds about right. 400 to 600 Vac
firing voltage then goes down to the 20V 1A range.

Would you verify that there is NO polarity to the fluorescent tubes
supply?
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Default Fuse size in IBM ThinkPad T22 wallwart power supply

On Fri, 16 Dec 2011 09:54:55 -0800 (PST), Robert Macy
wrote:

FINALLY!! I verified that the LCD screen is validly changing pixels,
all I need is the backlight.


Ok. The panel is good. That leaves the LCD inverter and/or the CCFL
backlighting tubes.

Measure voltage. If the tube is OFF, is that the firing voltage?
trying to get the tube to arc? sounds about right. 400 to 600 Vac
firing voltage then goes down to the 20V 1A range.


Could you please re-write that in English? It's not clear if you
measured anything, what you measured, how you measured it, and what
numbers were seen.

Would you verify that there is NO polarity to the fluorescent tubes
supply?


The CCFL lamp wires are not polarized.

However, the connector from the CCFL tubes is sometimes polarized. It
is possible to plug in backwards. It will sorta fit, but not be
seated correctly, resulting in no connection. My guess(tm) is is what
you've done. Unplug the cable from the CCFL lamps and LOOK AT THEM
carefully. Match it with the socket on the inverter. Hopefully, that
will fix it.

--
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# 831-336-2558
# http://802.11junk.com
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Default Fuse size in IBM ThinkPad T22 wallwart power supply

On Dec 16, 3:46*pm, Jeff Liebermann wrote:
On Fri, 16 Dec 2011 09:54:55 -0800 (PST), Robert Macy

wrote:
FINALLY!! *I verified that the LCD screen is validly changing pixels,
all I need is the backlight.


Ok. *The panel is good. *That leaves the LCD inverter and/or the CCFL
backlighting tubes.

Measure voltage. *If the tube is OFF, is that the firing voltage?
trying to get the tube to arc? sounds about right. *400 to 600 Vac
firing voltage then goes down to the 20V 1A range.


Could you please re-write that in English? *It's not clear if you
measured anything, what you measured, how you measured it, and what
numbers were seen.

Would you verify that there is NO polarity to the fluorescent tubes
supply?


The CCFL lamp wires are not polarized.

However, the connector from the CCFL tubes is sometimes polarized. *It
is possible to plug in backwards. *It will sorta fit, but not be
seated correctly, resulting in no connection. *My guess(tm) is is what
you've done. *Unplug the cable from the CCFL lamps and LOOK AT THEM
carefully. *Match it with the socket on the inverter. *Hopefully, that
will fix it.

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


Is there any possibility that the Lamp would work, the inverter would
work, but some 'controller' is toast?

Looking at the corrosion pattern on the inverter PCB, it looked like
the high voltage could have gained access back to the multi-pin
connector, which [to me] translates to "any IC driver wired to that
connector is likely to have been fired." Yet those same drivers are
probably on the system board. which may, or may not, affect the system
operation.

Measure voltage. *If the tube is OFF, is that the firing voltage?
trying to get the tube to arc? sounds about right. *400 to 600 Vac
firing voltage then goes down to the 20V 1A range.


Could you please re-write that in English? *It's not clear if you
measured anything, what you measured, how you measured it, and what
numbers were seen.


Oops, English is my native language, just doesn't often show.

Years ago, one of my clients made OCR electronics, my first design for
them was to design reliable fluorescent tube power source *and* make
certain the light pattern across a sheet of paper was uniform. To
'fire' the tube took any where from 400 to 600 Vac and once fired [the
tube is now filled with conducting plasma] the operating voltage drops
to 20-30 Vac at 1/2A, or so.

My [confusing] words were more of memories, than statements. I did
not, have not, no real way to do so yet, measure any voltages around
the Laptop.

Is the 'seating' of the connectors really that critical on the
Laptop? I mean those connectors are cheap, low insertion force,
miniaturized molex thingies that I find hard to believe provide
reliable connection at all. But, are they really likely to be the
problem, more than the likelihood of a non-operating component?

Regards,
Robert
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