A3640 rev. instabillity

[yogisumo]

I've had all 3 revs.  My original 3.0 would gradually slow down as system got warmer ( only with cards in machine ) and then lock up completely.  I now have a 3.1 and a 3.2.  I had Joe Archibald at www.archtech.ca change the backwards caps on my 3.1.  My 3.2 came out of an A4000T.

The cut and jumper part of the upgrade is not that difficult I think but I'm not sure about the pal upgrade.  You could try to contact Archtech or www.mrhardwarecomputers.com.  Unfortunately for you, they're in USA and Canada.

[yogisumo]

JohnFante wrote:
I see what you meen about the rev 3.0 :-(

When the system is cold everything works fine. But when it gets warm the instabillity comes.

Will it help to put and a fan inside?

What I did is open the case and put a fan blowing in over top of the case for testing.  At least one of the problems with the 3.0 revision is the sampling of the STerm signal on the bus.  As the system gets warmer, electrical resistance goes up which causes the bus problems.  The 040 is not overheating, but the heat exposes a marginal signal.  It's probably easier to find an accelerator or another a3640 than to try to fix that one.  At least, all you would need is the board and not the cpu....

[yogisumo]

Bunch of info on the A3640 here....

http://www.thule.no/haynie/