Gigabyte GA-Z270P-D3 Boot Loop

[pelolu]

Bought this second hand motherboard.
Seller told me was working fine.

Boot loop happens

24 pin + 8 pin power connectors without any processor, ram, mouse, keyboard installed. Loops inmediately, lasts half a second

Power with only CPU installed, the loop lasts 2-3 seconds.

No post, no beeps.
Motherboard looks fine, nothing rusty or burnt.

I´ve flashed official Gigabyte BIOS with CH341a usb programmer, both main & backup BIOS chip. Procedure finishes correctly.

PCH gets warm even loop is very short. CPU keeps cold.

Digital multimeter measurements:

Inductors near PCH show 12v & 1v

Inductors near cpu socket shows 1,02v & 0,86v

Inductor near RAM socket shows 1,2v

In continuity mode all solid capacitor seem good, even smd caps tested.

There are other many smd chips i haven´t tested, dont know how.

Bios chip is a Macronix 25L6473F, 8 pin is missing voltage.

Two PSU´s & processors tested with the motherboard.

Sorry for my horrible explanation, i am not a native english speaker.

Thanks

[taxxin]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Check out some of the discussions on here by DICKY69 I only read briefly about how there is bios and also the TPU firmware which is like a pre-bios bios thing, Im not exactly sure if this applies to your board but a z270 is for sure a high end board.

Sorry i cant be of much help

[dicky96]

Re: Gigabyte GA-Z270P-D3 Boot Loop

@taxxin
Actually it is SMDFlea that knows about the TPU firmware, I'm a beginner on that same as you. Apparently it does apply to all Zx70 motherboards

Unfortunately so far we couldn't identify the TPU ROM on my board but I'll get back to it and have a good look tomorrow

[pelolu]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Check out some of the discussions on here by DICKY69 I only read briefly about how there is bios and also the TPU firmware which is like a pre-bios bios thing, Im not exactly sure if this applies to your board but a z270 is for sure a high end board.

Sorry i cant be of much help

Thanks for the answer.

As far as i know my motherboard does not have the tpu module, or either i can´t find it.
Thought it was a feature implemented in Asus motherboards.

[dicky96]

Re: Gigabyte GA-Z270P-D3 Boot Loop

I think I located the TPU ROM on my board
https://www.badcaps.net/forum/showthread.php?t=83211

[pelolu]

Re: Gigabyte GA-Z270P-D3 Boot Loop

What about buying a new BIOS chip, and replace it with the M_BIOS one?.

Is it possible that the main BIOS chip is defective somehow?

[pelolu]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Main Bios

[dicky96]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Just reprogram the BIOS_M and BIOS_B with a known good file

[pelolu]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Just reprogram the BIOS_M and BIOS_B with a known good file

It´s useless, tried with Asprogrammer, Neoprogrammer, Colibri & a bunch of BIOS files downloaded from Gigabyte official web site and also the original dump file that came with the motherboard.

Must be a motherboard power issue, as the loop happens with no cpu installed.

[pelolu]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Tested the 12 Vcore mosfets with DMM.
4C010N (N channel 30v, 46A) Diode mode, drain-source voltage 0,496v
4C06N (N channel 30v, 69A) Diode mode, drain-source voltage 0,116v

High mosfets are low from specification 0,4-0,9v

[SMDFlea]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Tested the 12 Vcore mosfets with DMM.
4C010N (N channel 30v, 46A) Diode mode, drain-source voltage 0,496v
4C06N (N channel 30v, 69A) Diode mode, drain-source voltage 0,116v

High mosfets are low from specification 0,4-0,9v

Test in ohms mode, 2k on the meter if you have that. one way should be 250-500 the other OL/1

[pelolu]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Test in ohms mode, 2k on the meter if you have that. one way should be 250-500 the other OL/1

Made further measurements in diode mode

4C010N reversing probes 0L
4C06N reversing probes 0.116v. Same as positive source & negative drain

4C06N resistance mode 100 ohms (caps after inductors have the same value)
4C010N resistance mode 9,26 kohms

Are all in circuit measurements.
I can´t activate the mosfets by putting positive probe in Gate & negative in Source.

[SMDFlea]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Made further measurements in diode mode

4C010N reversing probes 0L
4C06N reversing probes 0.116v. Same as positive source & negative drain

4C06N resistance mode 100 ohms (caps after inductors have the same value)
4C010N resistance mode 9,26 kohms

Are all in circuit measurements.
I can´t activate the mosfets by putting positive probe in Gate & negative in Source.

Test in ohms mode

[pelolu]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Test in ohms mode

I call it resistance mode, I think we are talking about the same, right?

[SMDFlea]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Yes. The 600 setting is ok.

[pelolu]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Yes. The 600 setting is ok.

100 ohms mosfet OFF drain to source
The other way is mosfet ON?, can´t activate

[pelolu]

Re: Gigabyte GA-Z270P-D3 Boot Loop

Tested all solid capacitors with ESR meter, all below the worst reference value.