Abit IC7 no POST 2nd battle

[N3Star]

Hello,
previously I gave up on this MoBo, but here we are again. For starters I'll give a link to previous thread: https://www.badcaps.net/forum/showthread.php?t=95433
What has changed:
- I still don't have a PCI GPU, but I have a PCI dignostic board
- I measured the temperature and drain resistances of these hot MOSFETs:
(right) 3.3V line: 100Ohms, gets up to ~80C,
(left) 1.5V line: 430Ohms, gets up to ~65C
What PC diagnostic says:
-without GPU: goes through all post codes, keyboard is responsive, after hitting F1 key post codes go all the way to FF
-with known good AGP GPU: goes to post code "25", according to http://abit.ws/faq/code.html it's:

"DESCRIPTION:Early PCI Initialization:-Enumerate PCI bus number.-Assign memory & I/O resource-Search for a valid VGA device & VGA BIOS, and put it into C000:0
SYMPTOM: 00->C1->C3-> Stop at 25
CAUSE: BGA error
ACTION: Change graphic cards or unplug card and plug card back in again"

Ok, now what do they mean by "BGA error"? Dead MCH? Broken solder joints due to board bending? No communication with GPU core/VBIOS (I personally would go with this one because of these hot MOSFETS)? Maybe the caps I replaced were bad - I don't remember what capacity original ones were, but now I have there 2x 820uF+1x100uF(other caps are either 100ufF or 1000uF)?

[mon2]

Re: Abit IC7 no POST 2nd battle

The resistance to ground of the voltage rails in your post looks to be low.

What are the topside markings of the mosfets that are heating up ?

You can check if the mosfets are defective or not with a meter.

Remove all power -> Meter in resistance mode.

Assuming the mosfets are the typical 8 pin package,

source (1-2-3) & drain (5-6-7-8) ; what is the resistance reading ?
source (1-2-3) & gate(4)
gate(4) & drain (5-6-7-8)


Checking for a low resistance reading which for a mosfet means it is defective.

Reference:
http://electronicsbeliever.com/how-t...0good%20MOSFET.

see the resistance table in the above webpage

[N3Star]

Re: Abit IC7 no POST 2nd battle

Oh, we're going too much into new stuff, these are old TO-252 package, 60T03GH.
S-->D: right: 0.36V left:0.35V (reverse both 1V), which seems fine.
There is another change though - drains both look fine in terms of resistance (right - 1.3k, left D is connected to S of right one, has 2k Ohm), but source of left one is 69Ohms. That's the 1.5V line, going to AGP slot, but voltage seems fine with and without GPU.