Gigabyte G945GCMX-S2 ? Bad caps or bad board ?

[SuperDuty]

Hi guys,

Last year I picked up this motherboard in the dump, unfortunately it doesn't boot. It will power up, the CPU (and GPU if plugged in) fan will run at full speed, the CPU gets hot. Screen stays black, no beep, the usual symptom of a dead motherboard.

It seems like the board stood in a humid environement, because some connectors have rust spots on them, but I don't see any sign of oxydation on the components.

The main caps around the CPU are three Rubycon MBZ 16V 1500mF, and five poly caps 4V 560mF (with 723 SEPC on top, written in purple).
Most of the smaller caps around the slots are TK 6.3V 1000mF; with a couple of Sanyo WG and Panasonic CFJZ.
No bulged or leaking caps.

Could it be a capacitor problem ? Or a dead chipset or whatever else it could be.

Thanks !

[Th3_uN1Qu3]

Start by checking voltages. I've had a bad RAM regulator cause this issue. If Vcore, chipset voltage and Vdimm all check out okay, then it could be a bad BIOS.

[SuperDuty]

Well actually I've checked again, the CPU remains cold (must have been confused with the gasillion dead board I have with similar symptoms).
I get no voltage on the poly caps and voltage regulators around the CPU, but the three Nichicon MBZ near the additional 4pin PSU connector get around 12.85V.

[Th3_uN1Qu3]

Either bad BIOS or CPU not recognized - try an older processor like a Pentium D.

[SuperDuty]

I've tried it with a Pentium 4 630, a Pentium D 820, a D 945, a Celeron D 336 and a 347, a Core 2 Duo E6300, same thing.

Since the bios is soldered to the board, I guess I don't have much chance to save it...unless someone has another idea.
I do get about 3.80V on the BIOS chip, just to make sure it isn't burnt.

[buyerninety]

[edit; just remembered, this boardname apparently only HAD a ver 6.6]
I've got a GA-945GCMX-S2 Ver 6.6 (ver printed in corner closest to PCI
connectors), 3 caps close CPU socket are Sanyo 16V 1500uF N.E. 73 WG,
FOUR poly caps 4V 560mF (with 724 SEPC on top, written in purple), and
ONE poly cap same except 723 (not 724) located at tiny printed marked
position DEC4 (between two of the 724's).
Medium caps along RAM & PCI slots are Nichion C0728 PET 6.3V 1000uF
except for KZG 16V 470uF 7171 5L at EC172 EC23 (closest to LAN chip)
and KZG 16V 470uF 7171 5K at DEC8 DEC13 (closest medium in line to
PS/2 connector).
(After all that, prob not a cap problem.) Popular board for Hackintosh.

Bios chip appears to be located under PCI2, board printed marking MBIOS,
8 legged chip soldered, device printed writing contrast so poor can't
make out anything except- MK??, MX??.
If you have a jewellers lope or similar, could you see IF YOU CAN READ
ALL THE MARKINGS ON THAT CHIP.

http://www.gigabyte.com/products/pro...px?pid=2521#sp
states "Award Bios", "4 Mbit flash ROM". (Downloaded a bios for that
motherboard... in .exe form... extracted it... yes it's 512 KB in size.)

Mmmm...no 'Dual Bios' on this board, too bad. Can't see anything
explicitly about 'Virtual Bios' for this board in the downloadable utilities.
Don't clear the CMOS or remove the mobo battery!!.

In meantime... does the board upon powering on, make ANY beeps at all?
(Note; assuming you have a speaker connected - have to download the
motherboard manual from Gigabyte & refer to speaker pinouts on page 25)
Download the manual from Gigabyte website nearest you...looking for;
motherboard_manual_ga-945gcmx-s2_6.6_e.pdf

(Note; from manual, this motherboards default setting for initial graphics
display is a PCI slot video card, not the onboard VGA connector and not
the PCI-E slot.)

[SuperDuty]

Originally Posted by buyerninety

Bios chip appears to be located under PCI2, board printed marking MBIOS,
8 legged chip soldered, device printed writing contrast so poor can't
make out anything except- MK??, MX??.
If you have a jewellers lope or similar, could you see IF YOU CAN READ
ALL THE MARKINGS ON THAT CHIP.

http://www.gigabyte.com/products/pro...px?pid=2521#sp
states "Award Bios", "4 Mbit flash ROM". (Downloaded a bios for that
motherboard... in .exe form... extracted it... yes it's 512 KB in size.)

Mmmm...no 'Dual Bios' on this board, too bad. Can't see anything
explicitly about 'Virtual Bios' for this board in the downloadable utilities.
Don't clear the CMOS or remove the mobo battery!!.

In meantime... does the board upon powering on, make ANY beeps at all?
(Note; assuming you have a speaker connected - have to download the
motherboard manual from Gigabyte & refer to speaker pinouts on page 25)
Download the manual from Gigabyte website nearest you...looking for;
motherboard_manual_ga-945gcmx-s2_6.6_e.pdf

(Note; from manual, this motherboards default setting for initial graphics
display is a PCI slot video card, not the onboard VGA connector and not
the PCI-E slot.)

The BIOS is an MX -12G 25L4005AM2C 2U277600

And no beeps at all-

[buyerninety]

The PDF is here;
http://www.digchip.com/datasheets/pa...lbPMemiQt0-g9Q
I'll have a look at it & get back here later today...

[buyerninety]

OK, manual from Gigabyte for this board says
"Supports Xpress BIOS Rescue", although towards the end of
the manual it doesn't show the operation of that feature.
& from here;
http://forum.giga-byte.co.uk/index.p...2&topic=163.15
it appears that 'Xpress BIOS Rescue' may be the same as 'Virtual Dual Bios'.
"On every boot up of the MB, it checks the hard disk if there is any bios
image inside it.
If there is no bios image into the hard disk, the current main bios version
will be saved into hard disk (inside the special hidden area, not available
to standard OS).
That means the hard disk has the same bios version like the main bios.
If the main bios is damaged, the bios contents will auto rescue from hard disk.
If there is no hard disk, then it will recover from backup bios.
If you upgrade the hardware main bios chip, then at next boot the copy of
bios in HDD is also updated automatically."
"To have a copy of BIOS on your HDD you need to enable the following option in the BIOS:
^Backup BIOS Image to HDD^, which can be found under Advanced BIOS Features".
_
BUT in the manual for the GA-945GCMX-S2, where it displays explanation of
Bios screens ->no such option shown, so unclear if 'Xpress BIOS Rescue' is
applicable to this board.


Maybe put cpu fan connector on cpu fan board connection, put only one RAM in DDRii1 position, and with PATA and SATA HD connected,
check if there is any
attempt to access the HD by measuring at the F_panel pin block, pins 1 & 3,
(for HD drive access LED), or by placing actual LED on those pins.
If HD access occuring, try place uncompressed copy of bios on formatted,
empty HD. (and try placing also a compressed copy, who knows).
(Obviously won't be able to put in any HPA [Host Protected Area], but maybe Gigabyte fallback action is to simply check all of the drive?)

[buyerninety]

[Or perhaps you would like to peruse these first?]
If that avenue of testing is unfruitful, then these webpages describe some
testing actions on this motherboard; (Warning->it's all in Russlish)
http://translate.google.com/translat...e%2F945GCMX-S2

(If the word 'cartoon' is mentioned, I think that's a reference to the SuperIO - in this case an IT8718F Super IO.)

Assuming it's not hardware related like Russki website discusses, then
if you have other motherboards with the exact same flash chip, maybe
be prepared to do some hotflashing by unsoldering & lifting certain legs
of the flash chips on the nonworking and the good motherboard?

[SuperDuty]

Great information, I'll try that out and let you know. I've got gazillions of hard drives on hand for this. I'll put a clean BIOS file on one of them and see what it does.

I've already tried reflowing the Northbridge and the Southbridge chips, but with no change.

[buyerninety]

Probably not even going to need same chip... just came across
some apparent equivalencies on this webpage;
http://bios-repair.co.uk/Products/EE...Reference.html
so if the 8Mb parts can be swapped, checking should reveal a similar
level of equivalency for the 4Mb's, surely?
Cheers

[SuperDuty]

Ok I've just tried and there is no activity on the HDD. The led just stays on. I've also noticed the CPU and chipset did not even heat up actually :/

[buyerninety]

Th3_Un1Qu3 may have the more correct direction then, ...maybe
to download some of the various chips (on this motherboard)
documentation to see if their outputs are within expected ranges...
that russki website mentioned e.g. "Departed PWM power supply"
as seen problem on thesel boards, another post there gave e.g.
measured voltages for most of the mosfets if i remember correctly...