Iiyama E481s LCD monitor

[bigsky]

Dave's recent video on the Samsung LCD TV reminded me to ask about this.

I have two iiyama E481s 19" LCD monitors with similar faults - the screen intermittently goes blank and then comes back a second later. I've replaced the elec caps on both - some were bulging - but the problem hasn't gone away.

The SMPSU is based around an SG6841S IC and produces 12v DC which supplies the backlight inverters and two further regulators to give 5v and 3v3. All rails are normally good, but when the screen blanks the 12v rail drops to a few volts, so it's either cutting out or something is pulling it down. Lots of freezer spray hasn't revealed any possibilities, and I've looked at the boards with a magnifying glass and haven't spotted any dry joints. It's strange that both have the same problem. Perhaps someone has come across it before.

They're not worth much but I'd hate to scrap them as otherwise they are fine.

Any ideas?

[ElektroQuark]

Try to see the image with a lantern when the it goes blank. If you show images on the LCD then the problem is with the backlight.

[Rasz]

lamps might be going bad

is it repeatable? can you reproduce it quickly at will? if you can then experiment with different lamps connected