Xiaomi Mi Gaming XMG1902 ( datmadmbac0 rev:c) element nominals

[jnovikov2008]

Hi!
I need to repair Xiaomi Mi Gaming XMG1902, motherboard datmadmbac0 rev:c. Some elements have fallen off (marked with a red circle in the picture) and I need their nominals.
Thank you all for your help.

[mon2]

Start with identifying the pin # of the missing parts.

From the internet, found a YT video (Hindi) that shows the same series. See attached. From this screen grab, we now know the part is 128 pin TQFP package.

It appears the first missing (resistor - black body) is linked to pin # 33. Confirm it with a meter.

Repeat for the other parts. The small brown device is most likely a 0.1uf X5R or X7R ceramic capacitor at 6v3 or higher rating for the voltage since this part operates at 3v3 or lower.

After the trace confirmation, review the information and compare to other schematics that use this part to determine the missing parts.

Here is another board schematic with this part that can be used to hunt for the missing parts. Start with pin # 33.

[jnovikov2008]

From pin 33 of the chip, the signal is fed to 2 resistors.
The left resistor is connected to ground. The contact from the right resistor goes to the PCB and cannot be traced.
The connection is different on other PCBs.

[mon2]

Pin 33 on other logic board = MAINON on the ITE8987E.

The resistor to ground is probably a parking resistor and acts like a pull-down. Apply a 10k ohm resistor here.

The other resistor is the true series resistor for this signal with an active high state for true condition. Apply a 0 ohm (if nothing is available) or 10-100 ohm otherwise.

[piernov]

No reason for the GPIOs to be mapped the same on a different board with different firmware.

[mon2]

Good point. Measure the voltage to ground of each pad for these missing parts. Perhaps a resistor based voltage divider. Wait till we review it again.

[jnovikov2008]

Thanks for the advice. I will measure and post.