Technical Support Aorus X470 Ultra Gaming 5VSB fluctuates

[AMDBoards]

Hello,

I have Aorus X470 Ultra Gaming board. Board does not start and show no sign of live.
Checking for shorts on the ATX connector - no shorts.
Checking the power button - there is no constant 3V on it.
I started from the 5VSB coming from the ATX connector to see what is happening. The 5VSB fluctuates non stop. It goes from 4V to 0V and back.
I checked all the points on which 5VSB goes to start eliminating one by one and see if the 5VSB will stop fluctuate.
When removing OQ2 (it generates 3VDUAL_IO) the 5VSB becomes stable on all 5VSB points.
From the schematic OQ2 generates 3VDUAL_IO and sends it to 4 points.
1. via 0omh resistor to the SIO Chip legs 33, 64 and 06.
2. via two resistors to the DUAL BIOS config.
3. via SIO CAP to the OBC8 capacitor.
4. via SIO STRAP to 4 more SIO chip pins.

More or less all goes to the SIO chip.

My question is - can the SIO chip be causing this constant fluctuation in the 5VSB? Or I should search one by one on everything connected after it? The SIO chip has a lot connected to it.

Or should I try to inject a constant 3V/1A on the board and try to see what gets hot on it?

Schematic of the board is attached.

 

[Ahmad Safari]

Hello Sio most likely has a problem.
This voltage also enters the audio IC and usually the audio IC is more damaged.
You can supply 5 volts to the board and remove the hot part.

 

[AMDBoards]

Hello Sio most likely has a problem.
This voltage also enters the audio IC and usually the audio IC is more damaged.
You can supply 5 volts to the board and remove the hot part.

5v 1A as a start should be ok?

 

[AMDBoards]

Hello Sio most likely has a problem.
This voltage also enters the audio IC and usually the audio IC is more damaged.
You can supply 5 volts to the board and remove the hot part.

Ok, I applied 5V to the 5VDUAL mosfet and the Audio chip started to get hot.
The Audio chip (ALC1220) was changed from another board. The donor ALC1220 was never tested, so I don't know if it works.
After the change of the Audio chip, the fluctuations of the 5VSB become more relaxed but were still present.
I continued with the same approach and the next chip that got hot was the Asmedia chip for the USB 3 and USB3.1.
Again that chip was changed from the same spare board.
Now the 5VSB became constant, but another IC started to get hot. This time it was the IC for delivering power to the USB3.1 TypeC.
That chip was changed too.

Now the board starts, goes in to BIOS, goes in to Windows, Device manager shows all devices are working properly.
All USB devices work as expected.
All memory slots and PCIE slots work as expected.

Problem number 1.
LAN does not detect a cable when plugged.

Problem number 2.
No audio comes out of the Board.

Question 1> The LAN is Intel I211-AT. I can't seem to find how it does cable detection. Should I change the Chip from the spare board as well? Or the cable detection happens be using outside of the chip elements? The LAN Chip does not get hot.
Question 2 > Audio is still missing. I am not sure of the chip from the spare board is a working one. Should I order a new chip, or try to see if all component around the Audio chip work as well before that?

 

[Ahmad Safari]

Your power supply may have a problem with the standby section. Be sure to try another switch after replacement.
The audio IC can be replaced on other boards as well, it is enough just to have the same datasheet pins.For example, I replace these two ICs many times:ALC888 =>ALC662

Measure the input voltages of the ICs from its datasheet. If the voltages are normal, the IC may be faulty.


Reinstall the software drivers.

 

[AMDBoards]

I just changes to the Audio chip to a new ALC1220 (chip was only 3 euros) - Audio is perfect now.
The only problem remains the LAN.

The chip WGI211AT for the LAN is no longer available anywhere. I can find it only on ebay for around 20 Euro, but the board repair will get too expansive. Any idea if I can change this chip to a different model? Or from Intel to a Realtech one?
I know that if the pads are the same and the chip sends the same signals to the same pads it will work, the question is - how to find a suitable replacement option for that chip?

 

[Ahmad Safari]

You can also replace the LAN on almost identical motherboards. You just have to check the pins before they are similar.