Posts by Mattias

Well, this card is not working. I tried in several A1200's now. Order accelerators are working fine in the same computers, including mine.

I Guess I deal the warranty with the reseller?

Update: Still not stable, sometimes it works for a while, then it gets into a long loop of resets

Quote from Jens

Can you please provide the warranty ID of the card in question? I can check the database for anything special that may have been noted during QC, and I can of course take a close look at the QC picture.

Is it the one on the box? In that case it is TTJTA

Hmm, i read somewhere about accelerators crashing and someone suggested to run "cpu nocache". I havent tested very much, but when I ran this command I was able to start a few games without crashing.

Quote from W3DRK

I don't think a missing upper shield would cause your machine to become so completely unstable with an accelerator installed, but having that shield certainly wouldn't be a bad idea if one can be found. If this was a recent acquisition, is there any chance the person you bought your A1200 could provide you with one?

I don't understand why so many A1200 owners were eager to leave those out, it's not like they are difficult to put back. Considering these computers were designed to sit so close to CRTs with high-current degaussing coils, big power bricks, etc, that shield was put there for reasons beyond simply reducing spurious emissions.

In any event, hopefully the power supply you noted you use with your A500 will make a difference. If it can reliably power an accelerated 500, it should work fine with your 1200 too.

Otherwise I suspect your motherboard has timing --or rather signal integrity issues. In the past I believe the suggested mitigation was E123C, E125C = OPEN, E121C, E122C = 22pf NP0, and E121R, E122R = ferrite choke. Since you said all 4 caps are gone, it's possible someone hastily removed the caps when it wasn't warranted and inadvertently caused the issue you're having now.

Hopefully Jens doesn't mind my jumping in...apologies if so!

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I dont know the person that owned the A1200 before me as i bought it on an auction.

But the reason in this case was that someone had mounted a 3.5" hard drive, and there is no way that could fit with the shield.

I have replaced that with a CF adapter and card.

The Amiga 500 runs without any issues along with a HC508 Accelerator at 50Mhz, I havent got a single crash on that machine. So I should assume the PSU is okay for this as well?

Only two capactitors were mentioned with the included manual as possible culprits. These two looks like they were never mounted in the first place.

On the other hand, I have tried the card in a different A1200 with different PSU's, and its still not stable.

That other machine is normally running a Blizzard card and has no issues.

Quote from Jens

Such random crashes can still mean that *all* your power supplies are flakey. Remember that these are as old (or even older) than your A1200, which you gave a "professional re-cap" (whatever that is - I'd have to see the datasheets of the used capacitors in order to tell if that was professional or not). So you have an A1200 with band new caps, but a power supply with a 30-year-old output capacitor.

Other sources of random crashes are bad house wiring, missing earth connection, missing shield of the A1200 (or plain missing screws in that shield), or a mobile phone being placed too close to the Amiga.

What's the state of the PSU connector on the A1200? Does the computer continue to work if you wiggle that a bit?

Yes, I ment that i paid someone who have been working on Amigas since they were brand new to get new caps

Unfortunately I dont have the shield, it wasnt included when i bought it. Would that be worth trying to find one on ebay?

Nothing happens with the Amiga if I wiggle the connection.

Quote from W3DRK

What revision motherboard is in your 1200?

Rev 2B From Commodore

I tried with the PSU from the Amiga 500. Still the same issue.

Some GURU codes I got is

ERROR: 8000 0002 TASK: 400FA488

ERROR: 8000 0002 TASK: 400F1330

ERROR: 8000 0004 TASK: 40018F38

Any advice?

Quote from Jens

If you measure, don't look for "how much power" - look for regulation trouble such as step response and ripple. An Amiga does not need much power, but it requires really good regulation.

Also, it may be worth to check the rest of the system for any sources of instability - the prime suspect is any "specialties" on the IDE port, especially if you're using long cables.

Unfortunately I dont have the knowledge or equipment to perform such tests. I do however have 3 different Power Supplies that I can try with.

The IDE port does have a speciality, a CF card.. but the cord is really short.

The capacitors are not there, and the rest of the computer got a professional recap recently.

I could try the power supply that i got for my heavy accelerated a500, I will get back after i tried this

I have tested with a couple of differenct power supplies., but havent measured what i can actually get out of them

Hi,

I received a ACA1233n-40 last week and i cant get it to work properly.

My A1200 has fresh capacitors and none of the mentioned possible culprits were mounted.

Its running Kickstart 3.1.4 together with a clean install of Workbench 3.1.4.

The card shows as "working" in the boot menu, and i can see the memory correct and so forth. But if i run anything half heavy like a game, or just doing a "List all" in the CLI, the machine reboots and displays a black screen, sometimes a guru.

I have the lib installed, and also installed the 68030 library to get rid of boot warning.

I map the rom without any problems.

The Amiga works fine without the accelerator in, and i have tested it in another A1200 running 3.1, still fails..

Is there anything I can try to make it work, or should i just send it back to the store that sold it to me?