A1000 PAL chip wire mod needed?

[save2600]

Of all the A1000's I've owned throughout the years, never felt the need (out of necessity) to do the PAL ground upgrade. I did just do it to one of my latest mobo's, but that was only because I was trying to diagnose a potential expansion bus problem with an odd piece of kit. Turned out to be totally unnecessary.

I've heard of people needing a faster PAL or two for certain bus-type upgrades, but again, have never experienced that particular need either.

Hopefully this is clear enough. Rear left-most pins on J, K, L, N get tied together. Can't assume the ground's are always in the same spot though. Notice PAL's P & Q... rear right-most pins...

And then, run your lead of grounded PAL's to the ground of the expansion connector. C140 below the CPU or just above the CPU, are a couple of convenient ground leads.

Oh... and no, have never seen this mod by Commodore (not even units refurbished by them) where the ground mod was performed.

[save2600]

Our posts on ignore, block or what? Instructions on how to perform this and a pic are to be found at post #6.

...as I said in your other thread, more than likely a power supply issue, but if you want to try the ground mod, have at it!

[save2600]

Another angle:

[save2600]

Right, coincidence being - back in the day, when the power supply was still healthy.

The WCS slow-Fast RAM board is already properly grounded. And at several locations. Which is why the ground mod typically results in little more than a waste of time. Some stripped or lost case screws. Lots of agitation and maybe a borked plastic piece or two.  

If Blake's problem is solved by tying some grounds together (that are already tied/linked together, ELSE THE SYSTEM WOULDN'T WORK AT ALL) by adding even more wire to the system, guess I'll be eating my hat.  :laughing:

[save2600]

So you think his issue is a bad PS and NOT the grounding issue?  Sorry I will have to disagree on that.  Pretty much every A1000 I have used (like 5 so far) would NOT work with piggy backing Zorro expansion devices.  I had to do the grounding mod.

Been my experience, either way, I've provided written and pictorial examples within this thread on what needs to be done "ground mod" wise. As I said, good luck and we'll see!  

[save2600]

Here's a simple test for a weakening A1000 power supply:

How many external floppy drives can you attach before one simply doesn't work and/or is not recognized?

[save2600]

I did the mod. It didn't help.
bp

SURPRISE!  :laughing:

[save2600]

... or as save2600 has said a few times its probably a power supply issue?

Thanks for pointing that out.