Rubik Pi 3 board failure after connecting USB-C hub and USB mouse

Technical Sharing
1

Hello,

We need your help diagnosing a Rubik Pi 3 board failure.

The issue occurred after we connected a USB hub to the USB-C port and a mouse to a USB-A port. The board no longer appears to boot, and the debug/RGB LED does not light. The USB-C hub and mouse also no longer work.

During inspection, we found U1100, U1101, and U1102 (SY6288F1ABC USB power switches) shorted. We removed the three ICs, after which VCC_5V0 became available again. We have not bypassed the switches.

Our current measurements are:

Test point Measured voltage
TP602 12 V
TP603 5 V
TP604 (SOM_VBATT ) 4 V
TP605 3.3 V
TP800 (1V8) 0 V

Despite the main rails being present, the board still shows no apparent boot activity. Could you advise:

  1. What could cause all three USB power switches to fail during this connection?
  2. What should we check next to determine why the SoM’s 1.8 V rail is absent?

Best regards,
Huy

2

Hi qhuyduong

  1. It is speculated that EOS (electrical overstress) may have caused the device to fail.
  2. Are there any relevant fault logs currently available?
  3. May I ask if you have checked the waveform of Vreg_L18B?

BRs.