Amiga.org

Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: the_woz on August 25, 2006, 05:59:06 AM

Title: Broken A500 CIA
Post by: the_woz on August 25, 2006, 05:59:06 AM
Hi!
Sorry if this has already been asked, I tried the search function but didn't find anything usefull.

Three years ago, my A500 died while transfering a disk image to a C=1541 drive.
At first I thought the tranfer program just froze, as the machine didn't respond to either mouse or keyboard input (the picture on the screen were perfect, non corrupted).
But when I reset, all that I get was a grey screen, no drive click or anything.
When I open the machine it was very obvious that the CIA that drives the parallel port has died (it runs very hot).
The cause of the problem was a faulty 7406 on the C=1541, wich acts as a protection for the VIA6522, unfortunatelly there is not such a protection on the A500.

I had no problem fixing the drive,as the faulty chip is standart, but I had to put the A500 on storage as here in Argentina is almost imposible to get spares.

Now I have the posibility to get a replacement CIA, so I'm asking you:

Do you think that a new CIA will fix the problem? Or something else is broken?

Thanks in advance. (And excuse my bad english)
Title: Re: Broken A500 CIA
Post by: A1200Power on August 25, 2006, 08:10:22 AM
Hi Woz,

I think you should consider a Complex Interface Adapter swap ( long for CIA :-D ) This way you might be able to get your amiga back up but not for 100%. Simpel just take it out of the socket and change it with the other one. And power it up

I once blew up my cia due to a printercable. I tested it then by swapping the CIA, it worked but still needed a new one.

Hope this helps

Greetzzz Henk
Title: Re: Broken A500 CIA
Post by: the_woz on August 25, 2006, 05:47:26 PM
I already did that, but the only difference was that the drive 'click' once.
Title: Re: Broken A500 CIA
Post by: motorollin on August 25, 2006, 05:52:25 PM
I think you just answered your own question :-) If you have already swapped out the CIA and it still wouldn't boot, then there's clearly more to it than just the CIA. Paula controls the floppy drive. Maybe she is dead :-(

--
moto
Title: Re: Broken A500 CIA
Post by: the_woz on August 26, 2006, 12:57:45 AM
I read your post earlier this afternoon, Motorollin, and I get very depressed.
Well, just arrived from work and open the A500 to test again the CIA swaping, it did somewhat the same that I described earlier, but it was no drive click, just the motor spin.
Then I remove the bad CIA (which was now in the EVEN CIA place), I turn the machine on, and after some flashing screens (can't tell the colors as I'm using the monochrome out); nothing. Then I insert a disk on the drive, and, although the drive didn't spin nor click, the bootscreen prompting for a workbench disk appeared.
Please, tell me this is good news!  :cry:

Title: Re: Broken A500 CIA
Post by: LoadWB on August 26, 2006, 02:21:57 AM
A number of years ago I had an A500 with four 8250's stacked on top of each other to make a single work (old 6526 trick.)  Luckily, the only problem with each chip were different data lines which (again, luckily) tri-state when blown rather than ground out.  heheheh
Title: Re: Broken A500 CIA
Post by: melange on August 26, 2006, 08:42:57 AM
I reckon with one or maybe even two good working CIA's you'd be in with a good chance of getting it back in working order.

The fact that you got a Kickstart screen is a good sign.  In my opinion  :-)