820-00850 short on PPBUS

arnonabuurs

New member
Hi guys, this 820-00850 has no liquid spil and 0V and shorted on PPBUS. I put 1v in PPBUS line but nothing heats up. Before ramping up the voltage, how you usually look for shorts on these? I believe if I put to much power in I can short the CPU?

Edit see attached image found this, looks like a tiny bit of corrosion, that might be rip CPU I guess.....
 

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2informaticos

Moderator
Staff member
Probably dead CPU, after saw the picture.
But you've just injected AGAIN voltage on PPBUS w/o checking for shorted high-side MOSFET.
WHY???

Compare exact ohm value on PPBUS_G3H with the value on CPU coils.
If you get 0 ohm, then remove power chips from CPU; starting with the one in picture.
Check when PPBUS_G3H short goes off.
 

arnonabuurs

New member
I injected 1v, cpu gets 0.9-1.5v, how can it blow up from 1V? I replaced the bad chip now I have no more short and 12.29 on PPBUS

I have not seen any video from Louis on how to repair these boards so sorry if I dont follow the correct procedure, been reading up a=on the forum on how to find shorts for these boards and canot find any clear instruction, how am I supposed to figure it out...
 
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