CQ61 turn on and off ..not finding culprit here , help !

[highpulse]

Hey guys ,

Well got this one in the bench , and its giving me a bit of headhack ..
symptom : turn on then off after 1 sec . it happen to turn on once or twice with no problem , but still always doing the same now , on and off.
Cheked all coils to GNG - OK
Cheked S3 and S5 to KBC - OK (even like this replaced ENE D2,the same )
Flashed bios - OK
Cheked main starter signal , RSMRST - OK
PLTRST - not beeing feeded by Southbridge as it should .. this could be a problem , but not sure south bridge fault .
Cheked main lines once S0 is deploy , all voltages goes ok on coils.

weird thing is not having PLTRST and im getting all voltages during this second the machine is ON .

Battery does charge normally .

[highpulse]

Re: CQ61 turn on and off ..not finding culprit here , help !

maybe something on discharge i dont know , if she stay a bit of time without power , once i press on , she will turn on and stay on ,, after few attemps goes to same symptom , on and off .. kind weird

[highpulse]

Re: CQ61 turn on and off ..not finding culprit here , help !

weird thing also , everytime machine do that if i give a bit of heat on the clock gen ic , it wil turn on no problem , gives image etc all good
so relaced clock gen and crystal ... but does the same ... only giving a bit of heat it will work

[ala_borbe]

Re: CQ61 turn on and off ..not finding culprit here , help !

it must be cold joint... same symptoms i had with famous nvidia 6150 or so if i remember correctly...
after reflow, it worked fine
i understand its other platform, but by the symptoms problems sound like cold joint

[polytek]

Re: CQ61 turn on and off ..not finding culprit here , help !

agree to ala_borbe

[PlusCom]

Re: CQ61 turn on and off ..not finding culprit here , help !

Number of your southbridge?

[highpulse]

Re: CQ61 turn on and off ..not finding culprit here , help !

IBM . but alltough the clock gen is far far away from SB , and when i mean saying giving a bit of heat ,its just a bit of heat , like 1 or 2 second , can be a could joint , but if it is its around the small smd components around the clock gen .

[ala_borbe]

Re: CQ61 turn on and off ..not finding culprit here , help !

put some flux all around, reflow whole area around and test again