Expert: Gregory Donner - 11/2/2008

Question
QUESTION: Yo tengo una A4000,al encenderlo (power up) la pantalla  cambia a un color blanco y el equipo no arranca, que puedo hacer

ANSWER: Hi Jorge,

I'm not sure why your Amiga is not getting past the white screen during bootup, as it is the final step before loading Workbench (here's a description of what the Amiga does on bootup):

Amiga system test is a complicated set of routines which it must go
through before you can do any work on it. During the system test the Amiga is attempting to let you know if the system is well. Here is a list of the start-up activities:

1. Clear all chips of old data
2. Disable DMA and interrupts during the test.
3. Clear the screen.
4. Check the hardware ....checks to see if 68000 is functioning.
5. Change screen color.
6. Do a checksum test on all ROMS.
7. Change screen color.
8. Beginning of system startup.
9. Check RAM at $C0000,and move SYSBASE there
10. Test All CHIP RAM.
11. Change screen color.
12. Check that software is coming in ok.
13. Change screen color.
14. Setup CHIP RAM to receive data.
15. Link the libraries
16. Check for additional memory and link it
17. Turn the DMA and interrupts back on.
18. Start a default task.
19. Check for 68010,68020, and or 68881.
20. Check to see if thee is an exception ...processor error
21. If so do a system reset.

During this system test the Amiga is sending vital information to the screen with colors. If the system checks out ok, you will see the following sequence that you have seen so many times:

DARK GRAY: The initial hardware tested OK. The 68000 is running and the registers are readable.

LIGHT GRAY: The software is coming in and seems OK.

WHITE: The initialization test have passed.

Have you tried booting from a Workbench diskette? If so, do you still get the white screen?

Greg

---------- FOLLOW-UP ----------

QUESTION: Si, He tratado de hacer el boot con el  disco workbench incluso desconectando el disco duro,no se consigue cambio,
la pantalla es blanca y no lee el diskette.
Para referencia esta falla aparecio cuando la maquina estaba trabajando normalmente, se colgo y no arranco mas.
Gracias por toda la ayuda que puedan darme

Answer
Jorge,

Knowing the nature of the problem you're encountering, I would recommend finding a qualified technician to look at your system. It will take some specialized equipment and expertise to resolve it. Software Hut (www.softhut.com) in the U.S. and/or AmigaKit (www.amigakit.com) in Europe might be able to help.

I hope this helps!

Greg