[Coco] An interesting computer repair story

Robert Gault robert.gault at att.net
Wed May 2 18:18:50 EDT 2012


This is slightly off topic, but I do much of my Coco programming on a PC these days.

My Samsung SyncMaster 204B LCD monitor recently started flickering at turn-on 
and did not get up to selected brightness for about a minute. Things got worse 
with it taking 1-2 minutes to turn-on and 3-4 minutes to reach full brightness.

After proving to myself that the monitor was at fault rather than the video card 
or PC power supply, I took the monitor apart and examined anything I could see 
inside.
The back-light was not exposed, but two circuit boards were visible. Examination 
of the power supply board showed two electrolytic caps with swollen tops; 820uF 
25v. My local parts store did not have any 820uF but did have 1000uF caps. It 
did not seem to be a tuned circuit so +20% seemed close enough.

I put in two new 1000 uF caps, reassembled the monitor, and turned it on with 
fingers crossed. Eureka, it worked like new!!

After doing this on my own, I then thought to do a Google search on the 204B and 
found many hits in connection with capacitors. Hmmm, seems that this failure was 
well documented and known for 4-5 years. Samsung switched cap suppliers and 
settled for a cheaper version with poor quality control. There are even U-Tube 
movies showing how to open the monitor and replace the caps.




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