Age nibbeling away at my collection

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Erik Stillum
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Age nibbeling away at my collection

Post by Erik Stillum »

I had three MMII modules...one after one have ceased to work. The last one now locks up after 10-15 moves. Perhaps not reason to expect more then 30 years for such a small module, but sad anyway. I find some comfort in the fact that dedicated computers now have a small renaissance :).

Erik
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paulwise3
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Post by paulwise3 »

Hi Erik,

In Europe they are still available on Ebay for reasonable prices.
So take your chance ;-)

Best regards,
Paul
2024 Special thread: viewtopic.php?f=3&t=12741
2024 Special results and standings: https://schaakcomputers.nl/paul_w/Tourn ... 25_06.html
If I am mistaken, it must be caused by a horizon effect...
JeffB
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Post by JeffB »

One of two probable causes, either the ROMs or electrolytic capacitors have deteriorated. My bet would be the ROM. Either way, they should be repairable.
Cheers,

Jeff B.
mauben
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Post by mauben »

I find the MMII somewhat weak. My sample sometimes refuses to recognize key presses, or makes something weird and then goes back to normal operations.

I suspect some kind of "electronic crosstalk" creeping over inside, probably due to low quality materials or degradation.

No issues at all with the MMIV, Polgar and Vancouver / London modules, also reaching decent ages too.

Best,

Mauro
JeffB
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Post by JeffB »

Intermittent problems can often be the hardest to fix, but sometimes we get lucky and they're the easiest.

If you feel comfortable opening the module case, I suggest reseating the ICs that are in sockets, as oxidation can often cause the symptoms you describe. If it then behaves, you may want to carefully remove the chips, and clean any oxidation out, but again, only if you feel comfortable working this deep in the hardware.

Another potential cause could be oxidation building up inside the buttons themselves, causing intermittent contact. On my boards, I've also noticed a tendency for the MMII modules to not seat quite right, so pressing the button actually presses the board further into the module, rather than closing the contact! If that's happening, you could try to put non-conductive material, like small rubber feet or bumpers, between the bottom of the front of the circuit board and the module's case.

Of course, you would do all the above with the power removed. :)

Good luck!
Cheers,

Jeff B.
mauben
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Post by mauben »

Thanks Jeff,

I will definitely try.

In the end, MMII modules come at reasonable prices so that if I fry mine, punishment will be light.

Best regards,

Mauro
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Scally
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Post by Scally »

Hi Mauro,

Also the MMII Modul requires more voltage than the later modules, mine only works in an Unregulated board.


Cheers,

Al.
mauben
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Post by mauben »

Thanks Al.

That looks more complicated, as I only have 2 regulated Exclusive boards and 1 Modular.

I suspect that if I hook the 9 volts Master Chess adapter I will not go any farther with the MMII.

In case cleaning and reseating don't work, I will live with the quirks. My average gameplay has many more ...

Best,

Mauro
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