HP L1740 (BenQ close to q7t3) shuts down after some minutes

[ronszon]

Hi,
Same stuff I guess, but... I have a HP L1740 which is inside a BenQ, though the exact model I am unable to figure out... It has SMD inverter transistors and the inverter generally looks simpler than q7t3 (of which I have another, exactly the same outside, HP L1740 which I fixed thanks to this forum!)

I resoldered the connections to the high-voltage transformers after it started dying and it was fine for some months. Now, however, it keeps on behaving like follows: it starts up properly, display is nice and shiny, but after a few minutes (sometimes hours) it just shuts off. Not only the backlight, but the complete screen - the green power led goes completely off. If I push the power button the screen wakes up again with no trouble.
Any idea what can be wrong? It looks like the mainboard switches off or sth, but thats unlikely, isn't it? Should I just try resoldering the trafos again?

Thanks for any suggestions!

[selldoor]

Re: HP L1740 (BenQ close to q7t3) shuts down after some minutes

Pictures might help but yes reflow all the transformers main and inverters and also the 5707s and Fu***s if it has them and also any box capacitors and big resistors and diodes.
Some members reflow all big joints as a matter of course. Reflow = remove all the old solder and resolder with new leaded solder.
If you post pics

Welcome to the forum-
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed

https://www.badcaps.net/forum/attach...7&d=1280167246

https://www.badcaps.net/forum/attach...6&d=1280167246

https://www.badcaps.net/forum/attach...4&d=1280167246