Samsung 32" curved ,garbled image only at cold start.

[jonsig]

Good day, fellow EET´s  and repair affectinatos !

I have strange problem with 32" inch curved samsung monitor i got for free. (LC32HG70QQUXEN) and displays are not my stongest field.

Symptoms:
After the monitor is plugged in, the following is displayed.



1.Garbled image,
2.Those wide vertical segment appear one at a time with consistant interval, one after another.

Then after ~3 minuets the display appears fine, and stays like that even if it´s turned off and only in standby. I need to unplug the screen for a while so the problem appears again.

Work carried out:
Took random test of electrolyte caps with my peak ESR+ meter , every cap tested is in "OK" range. No ESR problem just slight degradation less than 10%.
Overall solder quality was good.
Flex cables re-seated and dont look damaged.

Im not sure what kind of failure mode i´m dealing with. Possibly BGA problem ?
tips woulld be appreciated.

[RoGeorge]

When something a couple of years old suddenly doesn't work only when cold, first thing, replace all the electrolytic capacitors with brand new ones.  Don't waste time measuring the caps, just replace them.

[wraper]

When something a couple of years old suddenly doesn't work only when cold, first thing, replace all the electrolytic capacitors with brand new ones.  Don't waste time measuring the caps, just replace them.

Except the chance this having anything to do with bad capacitors is close to zero. Not to say this monitor was made much later than the time when bad capacitors were a widespread issue.

Don't waste time measuring the caps, just replace them.

Don't waste your time needlessly replacing capacitors when you can easily measure ESR within circuit. The only case when you should replace caps with good ESR is when you know that particular series have problems or when other caps are bad.

[20Ola02]

Not much of any help, but I had the same problem on a 24" curved MSI monitor. At the beginning it only took 30 sec to clear the screen of the artifacts, but after 2 years of this happening when it was cold it took anywhere from 3-5 minutes to clear the screen. Trying to find a solution on a forum I came across a thread where they said it was a common thing and had something to to with a chip, cant remember the forum

[Rasz]

This dos look like a bonding failure on one of the ribbons