Mag lt782s power board problems

Hey. I have a lt782s (700p) that has the symptom they when the monitor is powered on, the light flashes on the front. After disassemble I find no blown caps, but what I do find is two "burn" spots on the component side of the board. This indicates that the components on the back have heated up. Flipping the board over I find chips at location U101, U105, and U102, (all 8 pin surface mount) and The solder joints look terrible. I do not know what type of chips they are as the top etch is unreadable. Any one have a schematic on this board? Or any advice. I am fairly proficient at this so please no jibs about leaving it to the pros....

Is it a really fast blink on the power light? If so, you might be looking at the wrong item. The fast blink means that the mainboard has an issue.

Like I've said sever other times on this board, there's an NPN transistor that is usually the culprit. Just yank it and replace it with a Radio Shack NPN and you should be in business (maybe bump it up a touch so that you don't have the same problem again).

Posted on

More: