AmigaOne: Causes and Solutions for the Dreaded Blank Screen

Copyright (c) 2000-2008 by, and the serial port advice comes from IntuitionBase

Possible causes of blank screen (no uboot prompt at bootup)

  1. CPU needs replaced (NutsAboutAmiga post #3 in "Amigaone RIP")
  2. CPU needs reseated ()
  3. Battery cr2032 needs replaced (nzv58l post #1 in "A1 boots with disk activity, but no screen. (This thing takes batteries)")
  4. Incompatibility with a card (MichaelMerkel post #1 and #11 in "radeon 9250 (HIS) - not working at all")
  5. RAM is incompatible ()
  6. UBoot flashed wrong ()
  7. Power supply could be faulty/not firmly connected (Wizzard_o post #2 in "A1 not booting")
  8. Faulty PATA/IDE cables
  9. Faulty PATA/IDE drives


  1. SOLUTION (mlehto post #4 in "Dying AmigaOne")
    1. Switch off PSU.
    2. Disconnect everything (AGP &PCI cards, SDRAM, battery, cables) except PSU cable from motherboard.
    3. Disconnect PSU from motherboard.
    4. Unplug power cable from PSU.
    5. Wait 5 minutes.
    6. Connect AGP/PCI graphics card, SDRAM, and a fresh battery.
    7. Connect PSU cable to motherboard.
    8. Boot AmigaOne w/o drives connected. If UBoot appears, the problem could be faulty ATA cables or drives. If UBoot does not appear, the problem could be a faulty PSU.
  2. SOLUTION (NeolFuller post #14 in "Dying AmigaOne")
    1. Remove CMOS battery.
    2. Install CMOS battery upside down.
    3. Reinstall CMOS battery right-side up.
    4. Boot AmigaOne. If UBoot appears, great. If not, try reseating the graphics card.
  3. SOLUTION (Tomas post #17 in "Dying AmigaOne")
    1. Remove CMOS battery.
    2. Unplug motherboard from PSU.
    3. Wait for a full day.
    4. Reconnect PSU to motherboard.
    5. Reinstall battery.
    6. Boot Amigaone.
  4. SOLUTION - Disconnect any serial cables connected to the AmigaOne.
  5. SOLUTION - Send the motherboard to kgrach.
  6. SOLUTION - Send the CPU module to ACube (you'll get a faster processor).
  7. SOLUTION (kgrach post #8 in "A1 died today")
    1. Pull power cord
    2. Pull battery
    3. Pull all cards
    4. Pull all cables
    5. Pull keyboard mouse and anything and everything from all ports.
    6. Disconnect everything from PSU if you haven't already
    7. Pull and re-seat memory. If you have more then one only put back one.
    8. Gently push on the back of the cpu module to make sure it is well seated don't push on heat sink
    9. Insert video card.
    10. Attach monitor to video card
    11. Attach PSU to motherboard
    12. Replace battery
    13. Attach power cord to PSU
    15. Hit the power button does it work?
If that doesn't work still leave everything disconnected and switch to 100 FSB.
If that doesn't work still leave everything disconnected and pull video card.


With the debug version of the OS4 kernel you can send detailed debug text to the serial port. Use a null modem cable to connect another computer to your AmigaOne serial port. Run a terminal program on the other computer so that you can catch the output. You have to set your terminal program to use 8 bits, no parity, 1 stop bit. The transfer speed must match the one you set in U-boot in the "baudrate" environment variable. Doing this will allow you to understand why a program crashes, and you will be able to help the coders by sending very detailed information about the experienced crash.

U-boot can also output text to the serial port. As an example when booting your A1, a text like the following is sent through the serial line:

U-Boot 1.1.1 (Oct 4 2004 - 16:42:03), Build: 10/04/04

CPU: MPC7455 v2.1 @ 933.333 MHz
Board: AmigaOne
DRAM: 256 MB
VGA: OK ..
In: serial
Out: serial
Err: serial
In fact, you can send any text to the serial port that is normally displayed in the console. You can do so like this:
] setenv stdout serial
] ide info
] setenv stdout vga

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