Beep Symptoms - Lenovo ThinkPad X1 Carbon Gen 12 Hardware Maintenance Manual

Blinking patterns Error codes
0288: Computer display error
0281: General embedded controller error
No-beep symptoms
Table 3. No-beep symptoms
Symptom or error
No beep, power-on indicator on, LCD blank, and no
POST.
No beep, power-on indicator on, and LCD blank during
POST.
The power-on password prompt appears.
No beep, power-on indicator on, LCD blank, and LED
indicators on Esc, F1 and F4 blink sequentially during
POST.
Solutions
1. Reconnect the display cable on both the
system board side and the computer
display side (service provider only) and
check the LCD panel.
2. If step 1 does not work, connect an
external display to your computer and
check the status (customer or service
provider).
• If the external display works, replace
the LCD panel (service provider only).
• If the external display does not work,
replace the system board (service
provider only).
Replace the system board (service provider
only).
FRU or action, in sequence
1. Run LCD Self Test.
2. Ensure that every connector is connected tightly and
correctly.
3. Reseat memory module.
4. Replace the system board.
1. Run LCD Self Test.
2. Reseat memory module.
3. Replace the system board.
A power-on password or a supervisor password is set.
Type the password and press Enter.
UEFI BIOS is performing memory retraining. The memory
retraining might occur if any of the following situations is
detected:
• Memory module replacement
• Total Memory Encryption setting change in UEFI BIOS
• Memory Reference Code [MRC] change when UEFI
BIOS updates
Do not press the power button to interrupt this process.
Wait a few minutes until the logo screen is displayed.
Chapter 4
.
Related service information
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