Amiga 600 – ACA 620 problems

[Wittfogel]

Hey guys,

I’m having some trouble with my newly acquired ACA 620 (Rev. 2) for the Amiga 600HD (Rev. 1.5), with Kickstart 3.X and WB 3.1 on a CF-card.

I've read a few other threads...

https://www.amibay.com/showthread.php?60798-ACA620EC-freeze-overheating

https://www.amibay.com/showthread.php?57621-A600-aca620-HxC-IDE2CF-freeze-problem

...but they don't address the booting problem, and the freezing problem doesn't seem to have a clear solution.

1) My machine has trouble booting. Mostly nothing happens, the HD-LED blinks now and then but nothing comes up on screen. Sometimes an all red screen appears.

2) If I can get it to boot it tends to freeze/lock after a while. If I can get it into a “good boot pattern” it can work fine even though I reset the system, but if I have it turned off over night the boot problem tends to be back again in the morning. It’s like the card needs a perfect working temperature, which it has after a few (10-15 boot attempts), but then gets too hot after a while.

Obviously, when I remove the ACA 620, everything works flawless.

What I’ve tried so far:

1) Cleaned the pins around the 68K CPU, maybe 3-4 times.

2) Removed the ACA 620 and put it back a bunch of times. I don't think anything has been damaged.

3) Used the two screws that came with the card (for additional grounding), but it doesn’t seem to matter one way or the other.

4) Most settings with regard to ACATune (nothing seems to make any difference).

What do you think could be done to remedy the problem?

1) Is the PSU too weak to handle the extra card? It’s a 5 V, 3.0 Amp brick. I know for a fact that the capacitors in the PSU has been changed.

2) Is it worth trying to disconnect the Gotek USB-floppy from power, would it leave extra juice for the card?

3) Is it the capacitors on the mother board?

4) Is it a faulty card?

5) Other issue X?

Sorry for the long post, but I’d appreciate any input that you might have to what could be causing this!

Thanks,
Samuel

 

[Pghulme]

mine worked for ages
then got your symptoms
took all apart and now works again

Amigas are fickle machines

 

[Wittfogel]

mine worked for ages
then got your symptoms
took all apart and now works again

Amigas are fickle machines

Ah, thanks for the response Pghulme!

When you say "all", what did you take apart? In retrospect, what do you think was faulty?

They are fickle indeed.

 

[Pghulme]

Don't know what problem was

had aca620
604n
indivision ecs
subway
4gb cf drive

all worked great, the one day not booting, just red fault screen.

Took all apart and reseated then all good again!

only thing that could be a problem is the Amiga I was using wasn't recapped.

 

[demolition]

Sounds like you had a bad connection somewhere which was fixed by reseating everything - probably between the CPU and the socket.

 

[Wittfogel]

Sounds like you had a bad connection somewhere which was fixed by reseating everything - probably between the CPU and the socket.

Yep, it would be the obvious thing in my case too. I don't really know what to do though, since I've already cleaned the pins etc. I've even tried blowing on it and on the socket, like everyone (shouldn't) used to do on NES-cartridges back in the day. Still, the problem persists. :huh:

Is there some liquid that you could slab on the pins to make them connect better...?

 

[Templar]

mine worked for ages
then got your symptoms
took all apart and now works again

Amigas are fickle machines

I bet it's not Amigas, but the hardware. ;-)

 

[demolition]

He includes a small manual with the ACA on how to clean the pins, or at least he did when I got one.

How exactly did you clean the CPU pins? I used a toothbrush and some IPA all around several times. Your Amiga could also suffer from micro-fractures in the CPU solder which would cause bad connections and in that case it needs to be reflowed (resoldered).

 

[Wittfogel]

He includes a small manual with the ACA on how to clean the pins, or at least he did when I got one.

How exactly did you clean the CPU pins? I used a toothbrush and some IPA all around several times. Your Amiga could also suffer from micro-fractures in the CPU solder which would cause bad connections and in that case it needs to be reflowed (resoldered).

Yep, tried with IPA and a toothbrush as the manual said! Will try a few more times before I give up.

If it's the CPU-pins/soldering then I'll probably have to learn how to live without WHDLoad, until I can get some soldering-wizard on the job - because I'd probably just **** it up.

How likely is it that it's the capacitors? Could old capacitors have this effect?

 

[demolition]

If the capacitors are old, they should probably be changed in any case before they make matters worse, but I would not be certain it helps in your case. The ACA620 has large decoupling capacitors for itself and Jens even wrote at some point that adding the ACA620 could generally improve the ripple on the supply due to the large capacitors mounted on the ACA.

 

[awmosoft]

I have a coupe of questions:

Which brand is your CF card?
Do you have a Chip RAM expansion?
Could you aslo put some pictures on this topic?

 

[Wittfogel]

I have a coupe of questions:

Which brand is your CF card?
Do you have a Chip RAM expansion?
Could you aslo put some pictures on this topic?

1) The "Amiga Forever" one with Workbench 3.1. Not sure what manufacturer that is. The problem persists even when I remove the CF-card though (and use the USB-floppy).
2) Nope, no chip RAM.
3) Without the accelerator card:

 

[balford]

Use an ATX PSU. I have an A600 with rev 2D board (supposedly the least stable with the ACA620), overclocked to 25MHz and it runs flawlessly using a PicoPSU fed from a good quality 12v PSU.

B

 

[Wittfogel]

Use an ATX PSU. I have an A600 with rev 2D board (supposedly the least stable with the ACA620), overclocked to 25MHz and it runs flawlessly using a PicoPSU fed from a good quality 12v PSU.

B

Ah, sounds like an interesting tip, because I don't think it's dirty pins at least.

How likely would you say it is that it's too little juice, and that a 12v PSU would solve the problem? Was yours working before you got the PicoPSU, or did you have similar problems?

 

[Deanp]

Hey guys,

I’m having some trouble with my newly acquired ACA 620 (Rev. 2) for the Amiga 600HD (Rev. 1.5), with Kickstart 3.X and WB 3.1 on a CF-card.

I've read a few other threads...

https://www.amibay.com/showthread.php?60798-ACA620EC-freeze-overheating

https://www.amibay.com/showthread.php?57621-A600-aca620-HxC-IDE2CF-freeze-problem

...but they don't address the booting problem, and the freezing problem doesn't seem to have a clear solution.

1) My machine has trouble booting. Mostly nothing happens, the HD-LED blinks now and then but nothing comes up on screen. Sometimes an all red screen appears.

2) If I can get it to boot it tends to freeze/lock after a while. If I can get it into a “good boot pattern” it can work fine even though I reset the system, but if I have it turned off over night the boot problem tends to be back again in the morning. It’s like the card needs a perfect working temperature, which it has after a few (10-15 boot attempts), but then gets too hot after a while.

Obviously, when I remove the ACA 620, everything works flawless.

What I’ve tried so far:

1) Cleaned the pins around the 68K CPU, maybe 3-4 times.

2) Removed the ACA 620 and put it back a bunch of times. I don't think anything has been damaged.

3) Used the two screws that came with the card (for additional grounding), but it doesn’t seem to matter one way or the other.

4) Most settings with regard to ACATune (nothing seems to make any difference).

What do you think could be done to remedy the problem?

1) Is the PSU too weak to handle the extra card? It’s a 5 V, 3.0 Amp brick. I know for a fact that the capacitors in the PSU has been changed.

2) Is it worth trying to disconnect the Gotek USB-floppy from power, would it leave extra juice for the card?

3) Is it the capacitors on the mother board?

4) Is it a faulty card?

5) Other issue X?

Sorry for the long post, but I’d appreciate any input that you might have to what could be causing this!

Thanks,
Samuel

Hi,

I have almost the same configuration as you (also have a 1mb ram expansion) and had very similar issues when I fitted my ACA620. I tried all the usual fixes - cleaning the 68k pins, refitting the accelerator, changing power supplies, making sure the ACA620 was grounded - but nothing worked. My A600 continued to lock up constantly or crash. I then decided to get my motherboard recapped - since then everything has worked perfectly and it hasn't locked up since.

Maybe give this a try if you haven't already.

 

[balford]

Ah, sounds like an interesting tip, because I don't think it's dirty pins at least.

How likely would you say it is that it's too little juice, and that a 12v PSU would solve the problem? Was yours working before you got the PicoPSU, or did you have similar problems?

I was having random Guru errors even when the system was bog standard, so rigged up the Pico and haven't had an issue since. It's being fed from a good quality 12v 3A PSU.

I have one of those Chinese volt/amp meters running on the supply, and the setup with ACA620 running at 25MHzis drawing 1.4A at 12v, so I'd say at 5v you're sailing close to the wind.

Recapping will obviously help with stability issues, but for me it wasn't the full solution.

B