820-2879 - woes

imoree

New member
Hello, have an 820-2879 no liquid damage - does not chime and does not start .
voltage @ q7085 fluctuates from 16.9 v down to 3.3volts and then back up again. as such, computer wont boot. power isnt stable @ u7200.
Replaced ISL6295 but no change, Checked Current limiting circuit and resistors/ caps , all check out fine. would love to see if this board is bootable or in the junk heap.
thanks
 

imoree

New member
again, fluctuates here as well . 12.58 v down to .03 volts then back up again.
on both sides of fuse

**EDIT**;
 
Last edited:

imoree

New member
WOW>. put alcohol on some suspect chips, u7500 fried. Changed and now voltage present and no more fluctuations. Now starts but no screen. no backlight no chime...
 

imoree

New member
but i have pp vcore, smc core , proper khz reading from RTC crystals? am i missing something here? i will replace this if you think that is what it is .
 
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