ACA1231 Freezing issues

[SuperNashwan]

Right, I'm pretty new to this (just posted my 'member introduction' in fact) so go easy on me. Here's the situation:

I've got an A1200 with 3.0 rom. A 4GB CF HD from amigakit with ClassicWB and WHDLoad installed using winuae. Also, I've just got one of the new ACA-1231 cards and I have installed the heat sink that came with it and use ACATune 1.5e to initialize it in the startup sequence.

Problem 1: The system freezes. I don't get any guru meditation error, just the screen freezes and whatever sound was playing repeats. I have to reset (soft or hard) to start the system again. The freeze can occur during playing a WHDLoad game or in WB, even if the system is just 'idling', i.e. I just boot it up and leave it. It seems to occur usually within about 15 mins but will be much sooner if I don't let it 'cool down' before trying again. This led me to think it was a temperature problem and indeed the heat sink on the ACA-1231 does get pretty hot, around 50 degrees C, but I suspect that kind of temp is not too bad? Without the card in the system is stable (although I can't do much with it!).

Problem 2: When I switch on, just after ACATune runs and the card is recognized, I get a System Request box popping up saying "Intuition is attempting to reset the workbench screen. Please close all windows, except drawers", with options to retry or cancel. If I wait to WB has loaded (In 4 colour mode, I think) then click retry it switches into 16 col mode with the nice copper backround. So, not too serious compared to problem 1 but thought I should mention it as possibly related. This happens with or without the ACA card.

Any thoughts?

Thanks in advance,

Nathan

[fitzsteve]

To prove that it's heat related you could temporarily fit a cooling fan onto the HeatSink (blutac maybe so it's not permanent)

Leave the trapdoor off and raise the A1200 on a couple of books.

I'm not suggesting you run your Amiga like this in the long term but if it runs reliably like this then you have an overheating issue!

The other thing could be that your PSU is overheating or just not up to the job.

Steve.

[Retrofan]

I'm not sure, but I would try to run Snoopdos from booting to see what the problem can be (at least with Problem 2).

[SuperNashwan]

Thanks for the suggestions. I'll have a crack at both tonight. Is there a power source on the A1200 board for a fan?

[mfilos]

No but you can easily get either 5V or 12V from the floppy power connector
- Yellow --> +12V
- Black --> COM
- Black --> COM
- Red --> +5V

[SuperNashwan]

Been busy over the last few days and think I have solved both probs:

Problem 1:

I tested if it was an overheating issue (supercooled the heat sink with my vacuum cleaner!). The system still hung...

Tried a fresh installation of ClassisWB Lite. That didn't help...

So I bought another A1200 (!) and thankfully everything seems ok now.

The new one has a different motherboard revision (1A instead of 2B, I think). Could this have been the issue?

Didn't get round to testing power supply as the new PSU I bought was faulty.

Problem 2:

I had foolishly omitted ">NIL:" from my ACATune command in the startup sequence. All sorted. Thanks for your help.

Next issue: Do I take the working motherboard out of its yellowed case and put it into my old nice white case? Is it straightforward?

Cheers,
Nathan

[prowler]

Originally Posted by SuperNashwan

Next issue: Do I take the working motherboard out of its yellowed case and put it into my old nice white case? Is it straightforward?

Hi Nathan,

First, congratulations on sorting out your A1200/ACA1231 problems.

BTW, it's not possible to be certain whether the Rev.2B motherboard would have been causing problems with the accelerator, even if it were faultless. This is because component tolerances make each case unique.

Now, regarding your plan to transplant your working internals into the shiny white case:

This should only be seriously considered if they are either both Commodore or both Amiga Technologies (Escom) cases. This is because the Amiga Technogies motherboards are modified to accept a PC-compatible internal floppy drive (so you can't even afford to get the floppy drives mixed up in that case).

That said, you'll be pleased to know it is quite a simple matter to swap the cases.

The case is opened by releasing five self-tapping screws from underneath (three along the front edge and two at the centre on either side - one under the front of the floppy drive opposite the eject button and one just behind the PCMCIA slot), then remove the top by lifting the front edge and gently pushing it backwards once it's clear of the keyboard to release it from the catches at the back. (Note that the centre screw along the front edge may be hidden by a warranty sticker if the machine is being opened for the first time.)

Take notes to make sure you know where all the screws and other parts came from and how they should connect or fit back together.

The LED PCB can be removed from the case top by releasing the screws. (Note that the four-wire cable is routed through the hole in the keyboard on that side.)

Be very careful when removing or replacing the screws. The threads in the case are delicate and may be stripped easily. Make sure you use a screwdriver which fits the screw heads exactly to avoid damaging them, and never force a screw unduly (difficulties are usuallty caused by misalignment of the components).

Locate the end of the keyboard ribbon where it connects with the motherboard and prise up the clip securing it in the socket by lifting it at each end. (If this is not possible because access to it is prevented by the RF shield, take a sure grip on the cable and pull it out gently but firmly against the resistance.) Lift the keyboard up slightly at the back and pull it backwards and out from under the tabs securing it at the front. Remove the LED cable from the motherboard header.

Now is the time to remove your accelerator card if you have not already done so via the trapdoor.

Next, you can remove the floppy drive by releasing the data ribbon and supply cables from the motherboard headers, two screws from underneath the case along the back edge and one at the front securing the mounting bracket to the inside of the case through the motherboard.

And remove your CF hard drive/IDE adapter/ribbon cable and hard drive cradle (if fitted) from the motherboard header.

IIRC, there will be no need to remove the RF shield (if fitted) unless you wish to do so.

In this case, carefully prise up the tabs securing it to the motherboard cradle and remove the two screws at the front (one from inside the case at the centre and the other from underneath the case on the left secured by a clip). Lift the RF shield away starting at the back until all the tabs are clear of the slots, then pull it forwards and unhook it from inderneath the motherboard cradle at the front.

Otherwise, just release the front two screws mentioned above and you're now ready to remove the motherboard assembly from the case.

Note: Some machines have a third screw securing the motherboard an inch or so to the left of the bracket which secures the floppy drive inside the case.

Lift up the front slightly until you can get your fingers under the cradle and pull it forwards until the rear sockets are clear of the cutouts at the back of the case and lift it out.

Disassemble both machines as described above and reassemble them after swapping the cases.
Reassembly is a direct reversal of the disassembly procedure.

When reconnecting the keyboard ribbon to the motherboard, replace the front of the keyboard under the tabs at the front edge of the case and lay it down at the back, then pull up the clip surrounding the motherboard socket, insert the cable and then push down the clip to secure it.

Now you know.

[SuperNashwan]

Wow, thanks for the detailed disassembly instructions.

I assumed both cases were Commodore models (they both said Commodore on the back and was no mention of Escom or Amiga technologies) and went ahead with the swap with no great difficulties. Now have a lovely A1200/ACA1231 setup in a nice white case.

The temptation now of course is to see if I can 'fix' the rev.2B motherboard with the timing fixes I've been reading about. Although I should probably quit while I'm ahead...

Cheers,
Nathan

[prowler]

Originally Posted by SuperNashwan

Wow, thanks for the detailed disassembly instructions.

And thanks for your confirmation that you used them with no great difficulties to achieve your objective.

That makes the time I spent typing all that lot in worthwhile.

[SuperNashwan]

I finally got round to having a go at the timing fixes on the original A1200 and and to my surprise they worked. Amazing what you can do with a soldering iron and a screwdriver.

Got a spare A1200 now, must be something fun I can do with it!

Hi supernashwan
I have the same revision board 2B with the same freeze problem ,
how did you fix yours ?
thanks

[magnetic]

This is because the Amiga Technogies motherboards are modified to accept a PC-compatible internal floppy drive (so you can't even afford to get the floppy drives mixed up in that case).

Prowler,

Does this mean that you can use any off the shelf PC floppy drive in the AT a1200s? Without any mods to the drive or cable? (which is what I have 2b as well iirc)

Also nice helpful post. That should be sticky for Noobs as its very detailed on how to disassemble the a1200. Nice job.

[SuperNashwan]

Hi disklexhick:

I applied the recommended timing fix. You gotta take the motherboard out of the case, and find the tiny capacitors labelled 123c and 125c, and remove them. I did this by applying heat with a soldering iron while levering with a tiny screwdriver until they popped off. Probably not the safest method but it worked and it's been totally solid with the aca-1231 since.

Hope that helps.

[prowler]

Originally Posted by magnetic

Prowler,

Does this mean that you can use any off the shelf PC floppy drive in the AT a1200s? Without any mods to the drive or cable? (which is what I have 2b as well iirc)

No, standard off the shelf PC floppy drives cannot be used in any A1200s, whether Commodore or AT, without mods to the drive.

The AT1200 motherboards are modified only to the extent required to accommodate PC floppy drives with a relatively simple modification.

To make a PC floppy drive compatible with a Commodore or unmodified AT motherboard requires modification of the drive beyond the point where it would still be practicable to reverse it. That's why Stedy's PC floppy drive to Amiga adapters are so useful.

Originally Posted by magnetic

Also nice helpful post. That should be sticky for Noobs as its very detailed on how to disassemble the a1200. Nice job.

Thanks. That was the intention. Now that the post is up, anyone can post a link to it.

I picked up a brand new ACA1231/42 recently to replace my Turbo LC1230 accelerator. The ACA is a lot more reliable and am able to use this with the trapdoor cover compared to the old Turbo which I had to have running with the trapdoor taken off becuase it was the only way it would actually work for any period of time without it freezing up. However I find the ACA still suffers from the occasional freezing problems which i am putting down to the fact that I am only using the original 25W power supply and am running a 4GB CF internally, another 4GB CF card via the PCMCIA slot along with an extra external floppy drive off it. If anyone can recommend a good place to get an old Datel Goliath 300W amiga power supply as i think Amigakit do not have these in stock anymore that would be really helpful :-)