Amiga 4000: Fastlane Z3 and A3640 Problem

[salocinx]

Hi

I have an A4000D with a A3640 rev. 3.2 and a Fastlane Z3. The amiga works fine without the Fastlane, but when plugged-in the Amiga doesn't start anymore (just black screen).

I have read in the Fastlane Z3 manual that there's a need to replace an IC below the CPU card, because there's a signal inverted by the A3640 that shouldn't... Here's what is written in the Fastlane Z3 manual for Amiga 4000:

- A3640 rev 3.0 (U209 with rev. -01) use 74FCT240
- A3640 rev 3.1 (U209 with rev. -02) use 74FCT244
- A3640 rev 3.2 (U209 with rev. -03) => not described in the manual

Since my A3640 is rev 3.2 (U209 with rev. -03), what kind of IC do I need ?

Any other ideas why the Fastlane might hang my system? The Fastlane works fine in my other A4000 with Cybervision and in my A3000 too...

Any help highly appreciated - thank you!

[hooverphonique]

is it maybe something to do with super buster being rev. 9 in one machine, and rev. 11 in the other?

what happens if you take the a3640 to your other a4000?

[salocinx]

Hi hooverphonique, thanks for your response. Both A4000 have Super Buster rev 11. The second A4000 is quite overloaded with Cybervision and SCSI module etc, so it would be a lot of work to test the A3640 in this Amiga. But you're absolutely right about systematically testing this configuration... hm... I will consider doing this as a last test. Maybe some other ideas?

[SpeedGeek]

What is the PCB rev. of your A3640? Rev. 3.0 PCB's have a /STERM sampling bug. It's possible someone upgraded U209 and forgot the cut and jumper mod.

You could check your A3640 electrolytic cap polarity and condition also.

The other obvious thing is to check is the +5 volt rail. When you add the Fastlane Z3 it's possible your aging PSU can't maintain the +5 Volt supply.

Finally, you should test the Fastlane Z3 in another system if possible.

Good luck...

[salocinx]

Thank you very much for your hints!

Originally Posted by SpeedGeek

What is the PCB rev. of your A3640? Rev. 3.0 PCB's have a /STERM sampling bug. It's possible someone upgraded U209 and forgot the cut and jumper mod.

Yes originally it was a rev 3.0. The /STERM fix has been applied. The PAL/GAL were all replaced/updated to rev 3.2 standard. The reset generator fix is also properly applied.

You could check your A3640 electrolytic cap polarity and condition also.

This was done by myself. I replaced all electrolytic caps with new ones and fixed the polarity where needed.

The other obvious thing is to check is the +5 volt rail. When you add the Fastlane Z3 it's possible your aging PSU can't maintain the +5 Volt supply.

Indeed, my PSU had only 4.70 V on the +5V line. Luckily I had another PSU to test. With this one I get 4.90 V - I guess that should be sufficient ... ?

Finally, you should test the Fastlane Z3 in another system if possible.

Already done, it works fine in my other A4000 and A3000.

Now the system starts with the Fastlane Z3 plugged-in and in early boot-menu there are two new entries both with state "working" (RAM-circuit and SCSI-circuit) - but the 16mb RAM installed on the Fastlane are not recognized by the Workbench. Jumpers are set all correctly according to the manual.

It must have to do with the A3640 and possibly DMA capability of the Fastlane Z3... Any further ideas ?