exxos's Atari, Amiga & retro forum

matt020 wrote: 21 Apr 2021 02:21 Could I please ask....

Are all revisions of A1200 motherboard affected?

What are the symptoms that would demonstrate that the timing fixes need to be applied?

The most common symptom is random lock ups.

As Steve says, it doesn’t matter what revision the board is, these caps are not supposed to be fitted but they are on certain boards, it’s random. If your 1260 had been working fine so far, then most likely you don’t have to do anything.

Steve wrote: 20 Apr 2021 15:33 The timing fix was removing capacitors that were accidentally fitted in the original factory, I would highly doubt that the re-amiga would have these capacitors fitted.

I don't know that much about electronics mass production, but how is it possible to accidentally fit a capacitor? :roll:

Laupert wrote: 21 Apr 2021 19:14 I don't know that much about electronics mass production, but how is it possible to accidentally fit a capacitor? :roll:

You give them a list of parts (BOM) and where they go (CPL)... I suppose the pads were on the board in the cad system and they may have needed to be manually removed from the BOM/CPL before sending to the board house. Or someone at the factory added them back on thinking there was an issue?

terriblefire wrote: 21 Apr 2021 19:20

Laupert wrote: 21 Apr 2021 19:14 I don't know that much about electronics mass production, but how is it possible to accidentally fit a capacitor? :roll:

You give them a list of parts (BOM) and where they go (CPL)... I suppose the pads were on the board in the cad system and they may have needed to be manually removed from the BOM/CPL before sending to the board house. Or someone at the factory added them back on thinking there was an issue?

Interesting. I have actually been having some strange issues for some time with my A1200 that goes away if I remove my M-Tec 1230. Doing some research I came across this page, though it specifically mentions Apollo cards and ACA1230.

Symptoms are not quite as described in this thread, but if the components weren't supposed to be there in the first place I guess there's not harm in trying to remove these components?

No harm at all, they aren't supposed to be there in the first place.

terriblefire wrote: 21 Apr 2021 19:20

Laupert wrote: 21 Apr 2021 19:14 I don't know that much about electronics mass production, but how is it possible to accidentally fit a capacitor? :roll:

You give them a list of parts (BOM) and where they go (CPL)... I suppose the pads were on the board in the cad system and they may have needed to be manually removed from the BOM/CPL before sending to the board house. Or someone at the factory added them back on thinking there was an issue?

We had a supplier fit a load of parts clearly marked on the BOM as DNF, we kept them as developer units as it's a pain to solder small pitch SMT JTAG headers.

alenppc wrote: 20 Apr 2021 14:36 Just a quick heads up that it is necessary to do the timing fixes for the TF1260 to work properly. Removing E123C and E125C from the A1200 motherboard is usually sufficient to achieve this.

My A1200 Rev 1D1 was affected by E123C and E125C and I removed them, hence TF1260 is stable instead of random lockups.