exxos's Atari, Amiga & retro forum

I can't get my 536 to work reliably, at all. I get freezes and lockups with gfx corruption after a few minutes it's running. I tried replacing the RAM chips, beefing up the caps next to the CPLD to 1uF, a million different CPUs but it keeps crapping out...

I used 1k resistors and resistor networks, same as on the 330. Am I missing anything obvious?

alenppc wrote: ↑Thu Jun 27, 2019 12:58 am I get freezes and lockups with gfx corruption after a few minutes it's running.

I had exactly the same symptoms when building two 534s. I began to suspect the issues was with my A500 setup rather than the cards themselves.

Unfortunately I can't offer any solution as I shelved them in order to get other tasks completed, although power supply would be my first suspect.

Edit: I should add that I was running them on an A500 Rev 6a with a standard 'light' psu and no other expansions fitted, have you got access to any other test machines to narrow down if the issue is with the card or the Amiga?

I am using 2k2 resistors and multilayer caps.

I’ve implemented Schmitt triggers for the clock for Alenppc.

Ive built it using TF330's BOM, and it works right from the start... RN's are 1k and ram cap is 22uF

@alenppc bad clock buffer or oscillator going flaky after getting warm?

Alen, do you test it on NTSC or PAL machine?
Will throw NTSC Agnus later today and try to run

I tested on: NTSC A1000, NTSC 500 rev 6, PAL A500+.

The A1000 is the one that gets the most graphics glitches. I replaced the CPLD in an act of desperation now Will try that in a bit to see if that makes any difference.

I never had any of these issues with the 534 and I built a good number of them.

It could techincally be also possible that my PCB had a factory defect, it happens sometimes.

I am using the same parts that I use for the 330 so in theory they should all be good...

Same thing even after replacing the CPLD. The only firmware that works stable is the one that Stephen sent me with the fast ram disabled. Yet the fast ram itself doesn't fail any tests.

Alen, this is very odd to me, it seems that You have some voltage problems there... Is Your 3.3V power regulator 1A?

This card draws more current, so please check voltage on Your cpu card maybe that's the issue. Beside of that - these rams are running on a double frequncy - maybe Your PSU makes some noise that ram doesn't like...

Im strongly recommend to all my customers to swap out PSU guts to Mean Well as these have adjustable 5V line, that helps to solve a lot of trouble..

Please keep us updated, wish You'll be able to get it stable soon...
Regards,

8 Bit Dreams

dalek wrote: ↑Thu Jun 27, 2019 8:15 am @alenppc bad clock buffer or oscillator going flaky after getting warm?

There is no clock buffer on the 536. The slow rising clock is solved in a different way

8 Bit Dreams wrote: ↑Fri Jun 28, 2019 7:05 pm Im strongly recommend to all my customers to swap out PSU guts to Mean Well as these have adjustable 5V line, that helps to solve a lot of trouble..

I have not even tried to run a TF536 on a standard A500 PSU. I do all my tests with a ATX PSU.

The only "real" amiga PSU i used was the CDTV one. I think thats a bit beefier than standard anyways.