Re: Fix for Benq FP737s 17" (Q7T3)




X Davmax:
1. Make sure that all the inverter transformer connections are resoldered
these connections seem fine to naked eye. I don't have a professional solder neither excellent soldering skills, i suppose i could worse the problem
2. Use a fast 3A fuse
Ok, I'll try to find it in a repair shop
3. Check the MOSFET in each circuit Q751 & Q743 (FU9024N) they should not read a short circuit.
I have ST D10PF06, I suppose they are equivalent. Could you provide a link...

Re: Fix for Benq FP737s 17" (Q7T3)

Thank you guys for the suggestions. I'll check them out and let you know.

If I understood the schematics correctly (btw i'm just a hobbyist), the 3A fuse provide current to power the inverter section, so blown fuse = no light, not even for half a second. am I right?


Please notice that I never rebooted the pc in these four days before failing, just stand-by (yellow led) since i read the Davmax investigation about the BLT_ON issue, unfortunately the workaround is too complicated for my electronic skills...

Re: Fix for Benq FP737s 17" (Q7T3)

I forgot to say there is no bulging capacitors, and solder joints seem fine at my inexperienced eyes. How can I test the capacitors?

Re: Fix for Benq FP737s 17" (Q7T3)

Krankshaft thank you for the reply!

I'm sorry if I haven't posted yet but the guys i bought the 2SC5705 shipped me the SMD version, so I had to wait they restock through hole version and sent me again.
Well I replaced all the 5705's to be sure and the 3A fuse. The monitor worked for four days, I was so excited, then it faulted again.

This time the CCFLs stay on only for half a second then they turn off. In this half second you can see the BenQ logo fading.
Then the power led is still green but you...

Re: Fix for Benq FP737s 17" (Q7T3)

Hi everybody!

I have a faulty Q7T3 too and found this very interesting topic. Unfortunately I have little or no knowledge in electronic repair

I checked the board and found the small 3A fuse open (didn't desoldered it). Then I desoldered all the four 2SC5707 in order to test them with a digital multimeter, as suggested here [url]http://www.kpsec.freeuk.com/components/tran.htm[/url]
It appears they perform correctly (base-emitter and base-collector like diodes, collector-emitter no conduction), though...