I have a 22" monitor GNR TS2200WA on a repair or discard basis. It
consumes 2W when powered; presumably on standby. But does not move off
standby to full operation. I can also not get the back fully off, just
some daylight along the bottom edge. Has anyone any guidance on either
mechanical or electronic aspects? Please?

Mike.

In article ,
says...

I have a 22" monitor GNR TS2200WA on a repair or discard basis. It
consumes 2W when powered; presumably on standby. But does not move off
standby to full operation. I can also not get the back fully off, just
some daylight along the bottom edge. Has anyone any guidance on either
mechanical or electronic aspects? Please?

Mike.

I've prized the case off and got sight of the two boards; one power and
one logic. Both well provided with component annotations, even for the
jumpers, but of course I don't have a schematic. Boards are connected by
a cable that, it says, supplies +5V and has one sense "ADJ" line and one
"On/Off" line. Quite like a PC or no doubt lots of other appliances
which have a low-power standby state. The power supply is marked that it
supplies +5V, and "optionally" +24V, +12V and -8V.
Measuring, the +5V started at ~3V and worked up to a rather wobbly 5V.
Must stick a 'scope on the wobbles to see if I can spot a pattern. The
"ADJ" line also varied ~2V / ~3V. But clicking the power switch made no
difference to the +0.1V on the "On/Off" line.

Mike.

Do you have an ESR meter? Whether or not, I would automatically suspect one or more bad electrolytic capacitors. If any have swollen cases, they are surely bad. Even if there is nothing visible, I would replace all of the electrolytics in the power supply.

In article ,
says...

I've prized the case off and got sight of the two boards; one power and
one logic. Both well provided with component annotations, even for the
jumpers, but of course I don't have a schematic. Boards are connected by
a cable that, it says, supplies +5V and has one sense "ADJ" line and one
"On/Off" line. Quite like a PC or no doubt lots of other appliances
which have a low-power standby state. The power supply is marked that it
supplies +5V, and "optionally" +24V, +12V and -8V.
Measuring, the +5V started at ~3V and worked up to a rather wobbly 5V.
Must stick a 'scope on the wobbles to see if I can spot a pattern. The
"ADJ" line also varied ~2V / ~3V. But clicking the power switch made no
difference to the +0.1V on the "On/Off" line.



Did you see this youtube about the monitor ?

I think I would start out just replacing the electrolytic capacitors on
the power board.

Many switching supplies seem to have blown capacitors. I have repaired
several items around my house by replacing capacitors.

One give away for me is to take the heat gun of my hot air rework
station and playing it around one or two capacitors at a time. If the
set starts working or manking a big change I replace them.

On Monday, April 9, 2018 at 5:07:02 PM UTC-4, Mike Coon wrote:
In article ,
says...

I have a 22" monitor GNR TS2200WA on a repair or discard basis. It
consumes 2W when powered; presumably on standby. But does not move off
standby to full operation. I can also not get the back fully off, just
some daylight along the bottom edge. Has anyone any guidance on either
mechanical or electronic aspects? Please?

Mike.

I've prized the case off and got sight of the two boards; one power and
one logic. Both well provided with component annotations, even for the
jumpers, but of course I don't have a schematic. Boards are connected by
a cable that, it says, supplies +5V and has one sense "ADJ" line and one
"On/Off" line. Quite like a PC or no doubt lots of other appliances
which have a low-power standby state. The power supply is marked that it
supplies +5V, and "optionally" +24V, +12V and -8V.
Measuring, the +5V started at ~3V and worked up to a rather wobbly 5V.
Must stick a 'scope on the wobbles to see if I can spot a pattern. The
"ADJ" line also varied ~2V / ~3V. But clicking the power switch made no
difference to the +0.1V on the "On/Off" line.

Mike.



Stuff a heat gun into the power supply and get it nice and toasty. If it powers up, recap the electros.

In article t,
says...

In article ,
says...

I've prized the case off and got sight of the two boards; one power and
one logic. Both well provided with component annotations, even for the
jumpers, but of course I don't have a schematic. Boards are connected by
a cable that, it says, supplies +5V and has one sense "ADJ" line and one
"On/Off" line. Quite like a PC or no doubt lots of other appliances
which have a low-power standby state. The power supply is marked that it
supplies +5V, and "optionally" +24V, +12V and -8V.
Measuring, the +5V started at ~3V and worked up to a rather wobbly 5V.
Must stick a 'scope on the wobbles to see if I can spot a pattern. The
"ADJ" line also varied ~2V / ~3V. But clicking the power switch made no
difference to the +0.1V on the "On/Off" line.



Did you see this youtube about the monitor ?

I think I would start out just replacing the electrolytic capacitors on
the power board.

Many switching supplies seem to have blown capacitors. I have repaired
several items around my house by replacing capacitors.

One give away for me is to take the heat gun of my hot air rework
station and playing it around one or two capacitors at a time. If the
set starts working or manking a big change I replace them.

The heat gun I have is a paint stripper. I use it a lot to shrink heat-
shrink tubing but am reluctant to play it on electronics. And I cannot
find the non-contact thermometer I was sure I had.

Viewing the youtube video I think was meant, I see the same capacitors
have bulges in my power supply. So though I cannot pop down to my local
Maplin (like the youtuber) because they have since gone out of business,
I have ordered replacements, fitted three, and the monitor is now
working!

It is sad that a board clearly marked 2007 already has multiple duff
components (assuming they are duff). I notice that the bulgy capacitors
have cross-scores on the flat end, almost like a hot-cross bun. The
scores recall a burst diaphragm, so I wonder if they are a safety
feature for components which are considered quite likely to fail
explosively! The words written on the items include "VENT", which makes
me think that I might be right...

As well as three bulging capacitors there are three flat-ended ones
which are also scored, so I hope those are "good".

I do not have an ESR meter but have noticed many discussions of such in
this NG over the years...

Thanks to all respondents.

Mike.

On Friday, 13 April 2018 17:56:05 UTC+1, Mike Coon wrote:

The heat gun I have is a paint stripper. I use it a lot to shrink heat-
shrink tubing but am reluctant to play it on electronics. And I cannot
find the non-contact thermometer I was sure I had.

Viewing the youtube video I think was meant, I see the same capacitors
have bulges in my power supply. So though I cannot pop down to my local
Maplin (like the youtuber) because they have since gone out of business,
I have ordered replacements, fitted three, and the monitor is now
working!

It is sad that a board clearly marked 2007 already has multiple duff
components (assuming they are duff). I notice that the bulgy capacitors
have cross-scores on the flat end, almost like a hot-cross bun. The
scores recall a burst diaphragm, so I wonder if they are a safety
feature for components which are considered quite likely to fail
explosively! The words written on the items include "VENT", which makes
me think that I might be right...

As well as three bulging capacitors there are three flat-ended ones
which are also scored, so I hope those are "good".

I do not have an ESR meter but have noticed many discussions of such in
this NG over the years...

Thanks to all respondents.

Mike.

Lytics can explode if no such precautions are taken during mfr


NT

In article ,
says...

The heat gun I have is a paint stripper. I use it a lot to shrink heat-
shrink tubing but am reluctant to play it on electronics. And I cannot
find the non-contact thermometer I was sure I had.

Viewing the youtube video I think was meant, I see the same capacitors
have bulges in my power supply. So though I cannot pop down to my local
Maplin (like the youtuber) because they have since gone out of business,
I have ordered replacements, fitted three, and the monitor is now
working!

It is sad that a board clearly marked 2007 already has multiple duff
components (assuming they are duff). I notice that the bulgy capacitors
have cross-scores on the flat end, almost like a hot-cross bun. The
scores recall a burst diaphragm, so I wonder if they are a safety
feature for components which are considered quite likely to fail
explosively! The words written on the items include "VENT", which makes
me think that I might be right...




Glad you got the monitor going. Seems that many of the simple repairs
are just replacing the capacitors around a switching power supply. For
some reason the switchers seem very hard on capcitors. They build up
heat and will vent the steam. Most electrolytic capacitors are not
really dry inside, but slightly moist. When the heat builds up and th
epressure is too much, they burst. That could be the reason for the
scores on the capacitors, not sure. They will have a way of bursting
and venting the steam with a large explosion for the most part.


If possiable you should look at the temperature ratings of the
capacitors. Some are around 80 deg C and some are around 100 or more.
Always get the highest temperature ratings you can.

On Friday, April 13, 2018 at 1:14:58 PM UTC-4, wrote:

Lytics can explode if no such precautions are taken during mfr


NT

Years ago I accidentally put line voltage on a board instead of the +5 it wanted.

They not only explode they stink up the whole room.

On Monday, 16 April 2018 20:11:07 UTC+1, Tim R wrote:
On Friday, April 13, 2018 at 1:14:58 PM UTC-4, tabb wrote:

Lytics can explode if no such precautions are taken during mfr

Years ago I accidentally put line voltage on a board instead of the +5 it wanted.

They not only explode they stink up the whole room.

ouch

NT

In article ,
says...

On Friday, April 13, 2018 at 1:14:58 PM UTC-4, wrote:

Lytics can explode if no such precautions are taken during mfr


NT

Years ago I accidentally put line voltage on a board instead of the +5 it wanted.

They not only explode they stink up the whole room.

The best stinky component I remember (from decades ago) was the selenium
rectifier!

I found that wikipedia has lots about capacitors. But not scratch-and-
sniff...

Mike.

On Friday, April 13, 2018 at 9:56:05 AM UTC-7, Mike Coon wrote:
As well as three bulging capacitors there are three flat-ended ones
which are also scored, so I hope those are "good".

Mike.
If the unit is still open, I would also replace those capacitors. Here in Silicon Valley, they are pretty cheap, probably less than the value of your time even at hobbyist rates.

On 4/16/2018 3:36 PM, wrote:
On Friday, April 13, 2018 at 9:56:05 AM UTC-7, Mike Coon wrote:
As well as three bulging capacitors there are three flat-ended ones
which are also scored, so I hope those are "good".

Mike.
If the unit is still open, I would also replace those capacitors. Here in Silicon Valley, they are pretty cheap, probably less than the value of your time even at hobbyist rates.

Agreed, I would replace them. I just got a Samsung 22" monitor (free
from CL), the owner said she screen flickered badly until it 'warmed
up', taking about 30 min's, replacing these 3 caps fixed it.

https://imgur.com/19DOhw0

https://imgur.com/gbciD1H

On 04/16/18 17:10, Mike Coon wrote:
In article ,
says...

On Friday, April 13, 2018 at 1:14:58 PM UTC-4, wrote:

Lytics can explode if no such precautions are taken during mfr


NT

Years ago I accidentally put line voltage on a board instead of the +5 it wanted.

They not only explode they stink up the whole room.

The best stinky component I remember (from decades ago) was the selenium
rectifier!

Yup. That horrible smell is also horribly toxic.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Friday, April 13, 2018 at 1:14:58 PM UTC-4, wrote:

Lytics can explode if no such precautions are taken during mfr
NT


Now I have remembered that in 1961 between school and college I had a
holiday job with Radford's in Bristol, UK, who made PA amps for
supermarkets. (Quite a new idea, then, perhaps.) Their snooty designer,
fully suited, came to review the first of his new design off the
production line, and I was one of the erks in attendance. As he bent
over it to inspect our workmanship a large electrolytic exploded and
decorated him with confetti. There were a lot of badly bitten lips and
choked-off splutters...

So I am familiar with the danger, after all!

Mike.

On Sunday, April 22, 2018 at 4:06:05 AM UTC-4, Mike Coon wrote:
.. (Quite a new idea, then, perhaps.) Their snooty designer,
fully suited, came to review the first of his new design off the
production line, and I was one of the erks in attendance. As he bent
over it to inspect our workmanship a large electrolytic exploded and
decorated him with confetti. There were a lot of badly bitten lips and
choked-off splutters...

So I am familiar with the danger, after all!

Mike.

When I worked in a plant, one of the corporate engineers came to visit. She dressed very stylishly - heels, nylons, jewelry - but incautiously leaned against a rail in the starch room, where we made glue. With lots of caustic soda. The nylons actually melted off, quite embarrassing. I had to feel a little sorry for her, but then again somebody would have warned her if she'd been a little easier to work with.