Benq fp931 q9t3

[mig.paiva]

Hello,

I have a Benq 19" that does not start neither the Led lights.
I checked the Power Board, and not seen swollen capacitors. Apparently voltages are OK. I have 5V (4.9 V) and 3.3 V (3.28 V) to enter the video card.
I measured the PW_SW signal entering the pin 2 of IC Flash MTV312MV64 which is 3.3 V and when I press the power switch it goes to 0v. I also measured the reset signal that is 0v, it's correct? The LCD shows no sign of life and not try to start....

I do not have much experience in repairing LCD however it seems to me that this IC MTV312MV64 works as bios/rom lcd ...
can someone give a hint where to start measuring and what should I measure?

I have the service manual with schematics for those who need it. How can I upload?

Thanks

[Rtech]

Re: Benq fp931 q9t3

measure the BL _On signal from the video board as you switch on,it should go to approx 3v..it may be called on/off.What you could also do..is WITHOUT the video board plugged in,just apply mains voltage to the Power board, plug in the backlights,and apply 3v from a battery between the on/off and a Gnd pin, and see if the lamps light.If you have not got a battery then a 1kΩ resistor from the 5v to the on/off will suffice.

[selldoor]

Re: Benq fp931 q9t3

I have the service manual with schematics for those who need it. How can I upload?

Thanks

If the file is not too big use the manage attachments button, which is found by clicking "go advanced" under quick reply.

[mig.paiva]

Re: Benq fp931 q9t3

The service manual of BENQ FP931 - Q9T3

[meyerf34]

Re: Benq fp931 q9t3

Thanks for the service manual!

My FP931's buttons don't work properly anymore. But it's not a dry joint on the the switch-board (that I checked out by resoldering all of the buttons), but obviously something from the controller board. (Alas, I could not make out any dry joints or busted components there.)

If you power the monitor up (insert a power cable) it will turn on (LED goes green) and work properly, but not react to any button (menu etc.). But strangely, once it enters energy saving mode (turns off, led goes yellow) you can turn it on and off with the ENTER-button (not ON/OFF-button though).

So it's not really a big issue, but a bit of a problem if you have to calibrate it etc.

[selldoor]

Re: Benq fp931 q9t3

hi meyerf are your boards the same as the q9t4 in this post
https://www.badcaps.net/forum/showthread.php?t=27988

[meyerf34]

Re: Benq fp931 q9t3

hi meyerf are your boards the same as the q9t4 in this post
https://www.badcaps.net/forum/showthread.php?t=27988

Hm. It's not the same problem.

And the Q9T4 (another 19" TFT) seems to be the successor of the FP931, so it's most likely it doesn't have the same circuit-boards.

But thanks for the link!

[robrock1]

Re: Benq fp931 q9t3

The Problem is from the IC myson mtv312mv64, it needs to be reprogrammed! I Have the same problem, i need the firmware and guide how to flash with isp. I am using willem eprom programmer!