I purchased the suggested items as mentioned by @minute but this had no effect on the quality of the image. I also removed the ACA-500 Plus and ACA-1234 to rule out whether it might be this hardware causing the issue, again this had no effect.
Are there any further suggestions as this is the final blemish on what apears to be an awesome product?
Hi,
Just a few suggestions from a person who just built a new A500++ motherboard, on purpose because of ZZ9000 (waiting for some good news on delivery of current batch).
Inspect Denise cable for cracks, get a multimeter and check each connection for continuity/shorts. Not likely but a good starting point.
Get additional shortest possible Denise cable as shorter gives less capacitance and noise crosstalk coming from external signals.
If possible, try it on another A500 motherboard.
If possible, try another power supply.
Check voltage levels on floppy connector, for stable A500 it’s important to get above 4.80V and less than 5.20V. Most refurbished/recapped original power supplies will get you around 4.9V which is fine.
There are around 1000 (?) of ZZ9000 being out in this moment; maybe some of them, even hundreads, being bought from collectors or for price premium in future.
I have a hard time accepting that the rest remains active only in hands of A2000/3000/4000 users. There should be at least some A500 guys without such issues. A1K.ORG is a great place with most active/creative individuals, just like Lukas. Writing in English is allowed. Register there and make a post, ask if someone has a working A500/ZZ9000 combination.
1st thing I checked was this sparkling effect - shows on my config, too.
Tried with another accelerator card, ACA500 (1st gen) alone and also with ACA-1232, situation identical.
Replaced current and functional Denise ECS with 2 also functional units, situation identical.
Replaced power supplies (another ATX, recapped brick A500), no changes.
Checked once again with shorter cables (the shortest one was less than 15cm long), situation identical.
Now back to square one - Lukas tests new firmware with his Rev5 A500.
That particular motherboard revision is likely to have Denise OCS (8362R8) and not Denise ECS (8373R3/R4).
When I replaced ECS Denise with OCS Denise, sparkling has gone.
Perfect clear video output. Root cause localized.
Wow, thanks for all the effort into discovering what looks to be the root cause. I’d come to a dead end in troubleshooting. Having only one A500++ there wasn’t much I was able to achieve.
Hopefully @minute can now work on a fix for ECS Denise and I can enjoy playing games without any distortion