Re: Dell E172fpb

folks,
have been busy with work and couldn't take time off to look at my monitor. well comin to the point i managed to force supply the IC751 by passing the Q761 and my ccfl backlights started to glow(i think this is the "full herbs" scenario that dockarl was talking about). But once i connect my AD board and my control panel pins dont work plus the led glows at a solid greenish yellow and i dont get to see the monitor self test on the display. looked like the ad/logic board got cooked. this is gonna be a lot more trickier than the inverter fix....

Re: Dell E172fpb

folks,
i observed that in Q761 both E/B are at 24V and the C which feeds to the IC751 supply pin9 stays at 0V. as far a q757 goes its e/b are at 0v and its c is at 24v(c drives the b of q761). does this mean both 761 and 757 are blown?
this is the case with both my boards (old n new alike). norris part's website is still down
regards
enkay

Re: Dell E172fpb

Transcend
thanks for ur tip. in my case Q761 is cooked. can you pls let me know which transistor model should i use to replace that?
btw folks i had one new inverter board shipped from norris parts, and guess what that board also failed to work. i dont know what is happenin. maybe norris parts just took me for a ride and their website is not working.
thanks n regards
enkay

Re: Dell E172fpb

folks,
i did verify the orientation of my newly installed MJE3055. They look OK. for all practical purposes the board doesn't seem to turn On at all. i am waiting for a replacement board to arrive in a couple of days.
in the mean time can someone suggest how to approach this problem systematically, that way we can isolate the issue to the specific component.
thanks and regards
enkay78

Re: Dell E172fpb

Folks,
first of all thanks to Dockarl for his tips on using the "MJE3055 NPN " transistor as replacement. it did the replacement and the monitor worked for a while. When i was putting everything back in place the system stopped working all together. not even the breakdown flicker. i checked the 2 amp fuse and it looks ok. but ccfl backlight outputs are also reading only 1~2 v only and not the expected 90V or so. i inspected to verify if there is any damage but there is no damage on the board.
any guesses on what may the issue???
...

Re: Dell E172fpb

Hi,
Does some one know what the Blue Cap values are if there is a need to replace some. C771 looks like it cooked and the meter showed that as a short. Moreover transistors Q750 and Q749 are cooked also.
Will changing the Interver board itself be the the best solution since work arounds dont seem to be that effective
regards