Switching Paula chip on A2000: side effects?

[jman]

Hello,

in order to understand how a kickstart switcher worked (thanks Jope!) I did some very slight and unobtrusive soldering on a v6.2 motherboard, around Gary and Paula chip.

Once finished these tests, I've unfortunately discovered that neither DF0: nor DF1: were able to boot anymore (before that, everything was ok). Booting from HD worked and any floppy inserted was saddenly tagged as NDOS:

After googling a bit, I've tried swithing the Paula chip: everything seems to working again, both DFx: drives boot.

So here's my doubts:
1) the spare Paula chip comes from a v4.4 motherboard: are they 100% compatible?
2) What in the world could have gone wrong with this original Paula chip? I attach some pics, for it looks good to me! Is there a way to perform any test on this very chip?

Thanks

[8bitbubsy]

There's only two revisions of Paula as far as I know, the 8364R4 found only (?) in A1000 boards and the 8364R7 which is in like 95% of all Amigas. Not too sure if R4 is pin compatible with R7, but I'm fairly positive that it is. Also, both of your Paulas are R7, so it's safe to swap 'em.

[Fingerlickin_B]

Just a quick question, but did you try re-seating the chip before replacing it?

You may find that's it's still okay & simply developed a bad connection due to twisting of the motherboard when removed for modification.

PZ.

[jman]

Originally Posted by Fingerlickin_B

Just a quick question, but did you try re-seating the chip before replacing it?

I had not to remove the chip itself when I tested the switcher, so in theory the chip placement didn't change, but yes, I tried pushing it down to be sure it was still in place.

[Jope]

So.. What exactly did you solder there and did you restore it to how it was like before?

[jman]

Originally Posted by Jope

So.. What exactly did you solder there and did you restore it to how it was like before?

I'm not sure I've understood your question, but I'll briefly recap what I did while testing the kickswitcher, after having mounted it in place:
- Connected one wire to CIA-B, pin 8 and the other to Gary, pin 5
- Then switched wires on the KS
- Then grounded one wire and leave the other on Gary
- Connected one wire to CIA-B, pin 8 andthe other to Paula, pin 33
- Then switched wires on the KS
- Then Jope said "hey, you need a switch!"
- Removed all the wiring, installed the switch "woot, everything works!", then tried to boot the Amiga and surprise surprise the floppy drives didn't boot anymore
- Replaced Paula chip, the floppy drives boot

I don't know what happened while executing these steps, but I'm sure that before fiddling with the KS I could boot the A2000 from DF0 :-)