L2 - R4.6 Touchscreen Malfunction

Modified on Tue, 27 May at 7:45 PM

According to the problem analysis result done by CCA, you can directly begin the subsequent troubleshooting process from the corresponding potential root cause.

1. System not Activated

STEP 1 - Check if the indicator lights on the Tinker Board and the power LED on the mini PC are lit.

Result 1 - The control board and the mini PC are lit.
Start "Touchscreen & Cables" chapter.
Result 2 - The indicator lights on the control board are not lit.
Start STEP 2.
Result 3 - The power LED on the mini PC is not lit.
Start STEP 4.

STEP 2 - Measure the voltage at the control board connector for the Tinker Board. The expected reading should be 24V.

Result 1 - The reading is 24V.
Start STEP 4.
Result 2 - The reading is not 24V.
Start STEP 3.

STEP 3 - Replace the power supply (see SOP here) and verify successful machine startup and touchscreen functionality.

Result 1 - The touchscreen works fine.
Issue close.
Root cause: The power supply fails.
Result 2 - The touchscreen is still blank.
Start STEP 4.

STEP 4 - Measure the voltage at the control board connector for Tinker Board. The expected reading should be 12V.

Result 1 - The reading is 12V.
Start STEP 6.
Result 2 - The reading is not 12V.
Start STEP 5.

STEP 5 - Replace the control board (see SOP here) and verify successful machine startup and touchscreen functionality.

Result 1 - The touchscreen works fine.
Issue close.
Root cause: The control board fails.
Result 2 - The touchscreen is still blank.
Start STEP 6.

STEP 6 - Replace the Tinker Board (see SOP here) and verify successful machine startup and touchscreen functionality.

Result 1 - The touchscreen works fine.
Issue close.
Root cause: The Tinker Board fails.
Result 2 - The touchscreen is still blank.
Start "Touchscreen & Cables" chapter.

2. Touchscreen & Cables

STEP 1 - Confirm that the HDMI cable, power cable, and touch (USB) cable of the touchscreen are properly connected at both the screen end and the Tinker Board end.

Result 1 - All cables are correctly connected.
Start STEP 3.
Result 2 - The cable(s) is loose or disconnected.
Start STEP 2.

STEP 2 - Reconnect the cables properly. Then, verify touchscreen functionality.

Result 1 - The touchscreen works fine.
Issue close.
Root cause: Cable(s) is disconnected.
Result 2 - The touchscreen is still blank.
Start STEP 3.

STEP 3 - Connect the cables to a new touchscreen and verify touchscreen functionality.

Result 1 - The touchscreen works fine.
Issue close. Replace the touchscreen.
Root cause: The touchscreen fails.
Result 2 - The touchscreen is still blank.
Start "Power Supply for the Touchscreen" chapter.

3. Power Supply for the Touchscreen

STEP 1 - Measure the voltage at the control board connector for the touchscreen. The expected reading should be 12V.

Result 1 - The reading is 12V.
Start STEP 3.
Result 2 - The reading is not 12V.
Start STEP 2. (If you've done the control board replacement in the previous step, escalate to PSE directly)

STEP 2 - Replace the control board (see SOP here) and verify touchscreen functionality.

Result 1 - The touchscreen works fine.
Issue close.
Root cause: The control board fails.
Result 2 - The touchscreen is still blank.
Start STEP 3.

STEP 3 - Replace the original HDMI cable with a new/functional one, and verify touchscreen functionality.

Result 1 - The touchscreen works fine.
Issue close.
Root cause: The HDMI cable fails.
Result 2 - The touchscreen is still blank.
Escalate to PSE.

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