A1200 with aca1200ec

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Don't Panic. Please wash hands.
  • Straight away I'd like to acknowledge that I purchased my a1200 used with a used aca1221ec. Any help you're willing to provide is appreciated but definitely not expected for a used purchase.


    I recapped the a1200 and upgraded to ks 3.1 I also did the timing fix by removing ec123 and 125. The machine seems to run perfectly fine without the accelerator card.


    When I first tested the accelerator the Machine wouldn't boot off the cf or with the cf installed but would boot from the floppy but no fast ram was showing. I then tried the three different jumper settings and now can't seem to get the machine to boot no matter which jumper setting I try. I get a video signal but only a blank screen.


    With the card removed the machine goes back to normal.


    Any suggestions are appreciated.

    Thanks Kevin

  • Straight away I'd like to acknowledge that I purchased my a1200 used with a used aca1221ec. Any help you're willing to provide is appreciated but definitely not expected for a used purchase.

    We support all iComp products, regardless of purchase date and 2nd hand or not. All software updates are free, don't even require registration - just go to the Wiki and download. There has been an update to the ACAtool just a few hours ago, fixing a bug in speed-settings for the ACA1221ec.


    When I first tested the accelerator the Machine wouldn't boot off the cf or with the cf installed but would boot from the floppy but no fast ram was showing. I then tried the three different jumper settings and now can't seem to get the machine to boot no matter which jumper setting I try. I get a video signal but only a blank screen.

    A typical problem is contacts: The accelerator's connector hat 150 pins, and specification of the other side (the A1200 side) say that the edge needs to be chamfered. On some A1200s, this is not the case, so pushing the connector all the way in has a counter-productive effect, as it lifts some contacts away from the board.


    Please try to pull back the card by 1mm and power up the computer. Cleaning the A1200 side with IPA and a micro fibre cloth may also help.


    Did you see the card ever work while it was in your posession?

  • Well upon much closer inspection it seems I may have found the problem. I or the previous owner but likely myself have bent one of the pins in the connector. Would it be possible to purchase a replacement connector.

    Thanks for helping out with this. After doing some more reading I have also chamfered the sharp edge on the edge connector to prevent this in the future.

    Thanks again Kevin

  • I'm sorry, the 150-pin connectors are not for sale. Exchanging the connector is so difficult that I believe 90% of the skilled DIY-people will still mess it up. The boards are soldered lead-free, and they are multilayer boards, so de-soldering the connector is *extremely* difficult, even with professional equipment.


    I've sold replacement connectors before, and every single time, we got the board back for repair anyway. We have been able to repair each and every one of the boards, but it would have been cheaper if we did it in the first place.


    What I can offer is to double-check if the bent pin is used at all. You may be able to remove the bent pin, and by that, remove the short that it creates. There's quite a few pins that are either not used or that are redundant. Please take a picture of the pin in question, also showing the edges of the connector, so I know which way to count. This may get us around the customs hassle that Brexit has created.