Help! Had Power Failure, now A400 won't boot...yellow screen

[marcfrick2112]

@moto: Yeah, I checked the voltages coming from the PSU with a multimeter, everything was fine [shrug]

Regarding ther reapir guy in KS, his name is Ed Jeffries, runs  a place called Video Lab, seems very good (Ibought an A1200 desktop from him couple of years back..) Number is 913-403-0045

[motorollin]

:-( Keep us up to date!

--
moto

[alexh]

http://it.aminet.net/hard/misc/errormessages.txt

Yellow on boot is noted as a strange error (12 on this list) but I used to get it all the time on my A600 if the Trap Door Chip RAM expansion had come loose.

Do you have any spare 30-pin simms?

Swap out the 30-pin simm that is the chip RAM one.

----------------------------------------------------

If you get yellow on power up, I believe that 90% of the Amiga is working.

The Amiga uses the 68k CPU to run POST. This means your CPU is working.

It uses the kickstart ROM to load the test routine that runs. It also CRC's it and this means your kickstart ROM is intact. (Or you would have a RED screen)

It uses registers in the Lisa chip to change the screen yellow etc.

Check your onboard battery, acid corrosion of the tracks near the SIMM sockets I imagine that can be responsible for yellow screens.

[marcfrick2112]

alexh: well, I don't have a spare 30-pin SIMM to try (that I can find)...I have 72-pins coming out of my ears...

Checked the battery, looks fine, and there is no corrosion that I can see....

Well, I haven't sent it off for repair yet, so I'll scrounge for a 30-pin SIMM...does it have to be 2MB to work?
 
Am grateful for all the ideas.
OK, my dad (also big-time Amiga fan) wants to get a spare 4000
The above-mentioned Ed Jeffries has a 4000 with a 40Mhz '040 WarpEngine, SCSI, 2GB HD, and CD-rom for $500.00, supposedly completley refurbished, you guys think I should go for it?

[bertambala]

marcfrick2112:  Thanks much!

[alexh]

£280 for that specification A4000 isnt too bad.

If it has KS3.1 and some extra Fast RAM on the accelerator and a BUSTER revision 11 then go for it.

Shame it doesnt have a graphics card or a network card but you could always get those later.

[Ilwrath]

alexh: well, I don't have a spare 30-pin SIMM to try (that I can find)...I have 72-pins coming out of my ears...

The Chip RAM is a 72 pin SIMM.  And, yes, it does need to be a 2MB, single sided.

And, as far as I know, the A4000 has no fuses at all, and not much to reseat other than processor card and RAM.  Possibly also SuperBuster, if you've had yours upgraded.  Pretty much everything else is surface mounted, for maximum pain in the arse when things go bad.  :-(

[alexh]

My mistake. They are 72-pin. Might be worth trying any you have lying around.

[pedro7]

Ilwrath wrote:
The Chip RAM is a 72 pin SIMM.  And, yes, it does need to be a 2MB, single sided.

It doesn't need to be single sided, the one in my a4000 is double sided.

[marcfrick2112]

Hi Everyone, well, I dont have a 2MB SIMM lying around, I may just
have to send it in to be repaired, thanks for everyone's help.

@alexh: The 4000 I am buying is a KS3.1/OS3.1 machine with
a total of 64MB RAM, and comes with Scala InfoChannel, so
I am going for it!