Samsung 23"
I knew it was dead when I saw it. The fellow wasn't sure if it was his computer or the monitor. It was cycling on and off. I knew it was the monitor. Removed the video cable and turned it on and still it cycled on and off. We ordered him a new one.
I took it home and opened the tool-less case ( you need spudgers for this... a butter knife works, iFixit has them for $4.95 http://www.ifixit.com/Tools/Metal-Spudger-Set/IF145-017 ).
3 capacitors had bulged and were heating up and shorting out causing it's power supply to cycle. Good thing most regulators today have short circuit protection or it would have fried the whole power supply board!
The power supply board is usually always separate from the video driver board and those are typically the only 2 boards in a monitor. I suspect the same for big screen LCD TVs but I haven't had the pleasure yet.
The power supply board has 2 portions. The low voltage supply that drives the video controller and the high voltage back-light supply that produces 700 - 1200 volts ac for the cold cathode fluorescent back lights. The problem is usually in the low voltage side from power surges, unless the symptom is the monitor goes very dim (lost the back-lights) then its the high voltage side and the board will just have to be replaced.
$1.45 and an hour or so later (takes time to find replacements from Digi-key) I had it fixed. It works on my desktop wonderfully. Samsung's have a nice picture.
I don't feel bad about fixing it and keeping it. 1) I might not have been able to fix it. 2) My time is money, diagnosing and fixing at circuit board component level is not the norm. 3) The capacitors were a gamble. it could have been other components as well as the capacitors.
So why throw it away when it can be fixed? Don't be afraid. Most power supply boards in LCDs can be replaced for about $25 to $35. $31 for my Viewsonic power supply board last time I bought one.
