Asrock G41M-VS3 R2.0 - repair journey

[N²x²N]

Hello again!

I got this board but no power on. Tested the usual.
https://asrock.com/mb/intel/g41m-vs3%20r2.0/

Shorts on +5VSB/+5V/+3V at ATX. 0.7 ohm, not 0. Something is shorting all 3.

Checked all the components after plugging PSU and found that the SB was very hot but bearable. Another smd, LM1117, responsible for the +3VSB to SB was instead ubearably hot (stick a finger and instantly feel the pain, warming everything in a 1/2 inch radius). I swapped it with another known working LM but still the same.
Legs have the following readings: +5VSB ok, +3VSB 1.8V - not ok, third leg not ok either. Something was pulling V from the +3VSB.
https://www.alldatasheet.com/datashe...MI/LM1117.html

Desoldered LM1117 and the SB would just get warm, there's my short.

My question: is the tiny ICH7 easy to desolder with just a heatgun? I'd like to experiment desoldering and maybe resoldering one from another dead board, and confirm it is the culprit.

Thanks for any help!


Btw, I have the schematics if anyone needs them. Or just look up for Asrock schematic diagrams.

[N²x²N]

Re: Asrock G41M-VS3 R2.0 - repair journey

No repair for this one.
I desoldered the southbridge and the shorts went away. A heatgun with preheat from bottom worked. It took like 5 minutes though, sounding like chip killer having to go up to 350°C to actually remove it.
A few pads came off but they were NC or GND. like 6/7 in all. Not bad for a first time.

It's not economical to replace it, let alone doing the job on the no-room placement of the chip.
Now it's a donor board for what's on it.

Really interested in knowing how it could have happened.