Re: Dell Precision 470
Beg you pardon asking this due your problem was 2 years ago and I´m having now the same problem.
I want to ask you, if you can recall, did you pulled the ceramic cap at the top side of the electros you had mentioned? what happened? was it short circuited?
I´m measuring 5 ohms on the ceramic C264 (at top side of electros if watching from systemboard backside), not sure if the coils close to it have some effect.
After a blackout, symptoms are as describer on this threats, B led amber; power led blinking amber. I had to replace lytics C242 and C254 due to brownish dielectric/electrolytic on them, but same ambers leds, no boot.
Installed an spare but used PS, pulled everything (memories; video card; etc), power led blinking green and beeping while reinstalling the pulled components. Assuming it was OK after replacing everything, I put the 470 back in place connecting external cables (video; lan; etc, etc) and B led back!!! Murphy law.
The MOSFET Q23 T70N03 shows signs of heat, hard to identify or see the ID code on it, maybe the caps drained to much current front it but not short circuited.
Also I'm measuring now close to 360 ohm at the 3.3v line in the power 24 pins connector without PS connected and red tester´s lead on 3.3v pin, if I swap tester´s leads I read 196 ohm!!! is my tester bad? Fluke 73 series II.
Appreciate in advance your help.
to check the ceramic. Or it could be anything else 
I want to ask you, if you can recall, did you pulled the ceramic cap at the top side of the electros you had mentioned? what happened? was it short circuited?
I´m measuring 5 ohms on the ceramic C264 (at top side of electros if watching from systemboard backside), not sure if the coils close to it have some effect.
After a blackout, symptoms are as describer on this threats, B led amber; power led blinking amber. I had to replace lytics C242 and C254 due to brownish dielectric/electrolytic on them, but same ambers leds, no boot.
Installed an spare but used PS, pulled everything (memories; video card; etc), power led blinking green and beeping while reinstalling the pulled components. Assuming it was OK after replacing everything, I put the 470 back in place connecting external cables (video; lan; etc, etc) and B led back!!! Murphy law.
The MOSFET Q23 T70N03 shows signs of heat, hard to identify or see the ID code on it, maybe the caps drained to much current front it but not short circuited.
Also I'm measuring now close to 360 ohm at the 3.3v line in the power 24 pins connector without PS connected and red tester´s lead on 3.3v pin, if I swap tester´s leads I read 196 ohm!!! is my tester bad? Fluke 73 series II.
Appreciate in advance your help.
Comment