820 3330 dead

EJS

New member
820-3330 board, customer states the were using the machine, heard a popping noise and smelled a burning odor. Board is not liquid damaged, and dont see any physical damage. PPBUS_G3H is dead short, when I inject votage the board heats up right around the corner of the CPU, but it really seems like the heat is coming from inside the board. I dont really have high hopes for this one, but thought I would ask. I have used IPA and freeze spray as well, and the heat dissipates in the same fassion as it looks on
 

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2informaticos

Administrator
Staff member
Too much hurry to inject tension.
You MUST first which power rail is first.
In your case seems like an high-side MOSFET is shorted.
Find it, remove and see if PPBUS_G3H is OK.
A low value from PCH/CPU can look at short on PPBUS_G3H...
 

EJS

New member
2informaticos, I have littarly just checked every single rail, non are short, all VCORE look good. The only rail short is PPBUS.
 

EJS

New member
2informaticos, I dont know what you mean by 200 ohms scale? Are you asking for ohms readings on l7030 and l7530?
 

2informaticos

Administrator
Staff member
If you really have 0.09ohm=90miliohm, CPU is fried.
CPU should have aprox 1-1.5ohm, if is i7.
I think you don't post correct the values...

Left one side of L7510/20/30 and see if PPBUS_G3H goes high.
 

EJS

New member
2informaticos, I appreciate your help unfortunately I had to return the machine to the customer. Those are the correct values 100%. Someone else suggested that the machine was probably dropped forcing the heat sink pillar into the board shorting out the trace. Thats exactly what it looked like to me. I didnt consider that pillar at first, but it makes perfect sense. Thanks for taking the time to help.
 
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