Re: HP 1755 Benq Inverter Board

Hi Toasty! I have tried your advice. I replaced all electrolytic capacitors on the board. It was running fine for a few days straight (I was doing an extended burn-in test on it) It worked without problems, I thought I had it fixed. BUT, I changed the brightness of the backlight as it was only set to 60% When I changed it to up around 90% or so, the C5707 transistors blew again! So, it seems that the same problem still exists.

Should I now look into replacing the plastic "box" capacitors and blue capacitors? I don't know what...

Re: HP 1755 Benq Inverter Board

Hi Toasty, thanks for the reply! I will try to take some pics of the board and post them up soon. It seems that all caps look fine physically (no leaks or buldges) But as I have read from you guys in the forum, this doesn't mean that all are functioning! I have a multimeter with a "Capacitence Check" function. It measures low capacitence levels ( < 1 micro farad I believe) I ran this on the plastic "box" capacitors in between the C5707 transistors as well as the blue disc capacitors downstream from the secondary transformers...

Re: HP 1755 Benq Inverter Board

Thanks for the reply! I took your advice and replaced the transformer with a known working one. Unfortunatley, this still did not resolve the issue! The monitor is now flashing on for a second, and then flashing off repeatedly. So, it seems to be cycling on and off. There is also a few audible clicks coming from an unknown component on the power board.

After a few minutes of this "on and off" with audible clicks, the C5707 transistors popped and fried once again! What else would you suggest at this point? I do not know what...

Re: HP 1755 Benq Inverter Board

Hello Krankshaft. Thanks for your many posts on the BENQ 48.L1A02.A00 boards. You seem to have lots of experience with them! I myself am trying to repair the same power board from my broken HP 1955 LCD monitor. I am experiencing the same problem as in this post. I have replaced all 4 of the C5707 transistors (2 tested bad) on the board. I hooked the monitor back up. It worked fine for about 2 hours, and then smoke appeared, and it stopped working. I took the monitor back apart and found that 2 of the C5705 transistors are blown once again. I Replaced...