Mephisto Monte Carlo Fault

[X__Gandalf__X]

Bought this on EBay many years ago.
Great condition. but with a minor fault from day 1.
The problem is with the h file.
The h1 light stays on, and when a move is made by the computer, the correct lights work ok, but in addition, another h light comes on.
Example - I move h2h4. Computer responds h7h5. Correct lights come on, along with h1 (constantly on) and h5 (which goes off when I make the move).
What do you think is likely to be the fault? Do I put up with it or attempt a repair? I have very little experience of such repairs.

[Berger]

Hello,

What you are explaining may be due to various faults in the sensory board. But the first thing to rule out is the failure of the magnetic sensor (reed switch) of H1. If you say that the LED in that square always stays on, why not think that it is as if there were no piece on it, i.e. that the reed switch in that square could be faulty (contacts open despite the magnet on it). But to repair this you need to have a minimum knowledge of electronics and of course the right tools.

Anyway, in Monte Carlo if the H1 sensor is faulty, and therefore it is as if the Rook is not in place, you can make the first move of white and black, but you would not be able to continue playing. If this is not the case, the problem could be on the H column but somewhere else. You would need a multimeter, soldering iron, etc. to check that column: sensors, LEDs, solders, jumpers... as being a matrix they share a circuit.

Best,
Gerardo

[mychess]

Hello,

Two ideas:

- can you switch to position setting mode?
If so, clear the board, a king + something against a king, all elsewhere than on the h-file, and check if you can play.
- perhaps a weak reed relay, try to put 2 or 3 pieces on h1.

Cordially

[Larry]

For dicky reed switches I keep a small but powerful neodymium disc magnet and put it on the base
of a chess piece. In your case a white rook. There’s a good chance the ‘h1’ light will go out. Of course
the light will most likely come back on when you remove the rook, but it will pinpoint the problem.
Worth a try regards…

[X__Gandalf__X]

Tried a few suggestions without success. Then tried magnet on H1 and things have got worse.
Now 28 lights come on and stay on. Reset and Clear don't work. Nothing on the display.
Looks like it's a write off. Thanks anyway.

[Berger]

Hi,

Do not despair. I can repair that chess computer if you want me to. I have sent you a PM.

Best,
Gerardo

[Steve B]

Hi,

Do not despair. I can repair that chess computer if you want me to. I have sent you a PM.

Best,
Gerardo

Well Done Regards
Steve

[X__Gandalf__X]

Hi,

Do not despair. I can repair that chess computer if you want me to. I have sent you a PM.

Best,
Gerardo

Thank you!

[Larry]

Hopefully there will be a happy ending. I hope you don’t feel I gave you
a bum steer with the magnet advice. I meant well, and have had good
results in the past.

[Berger]

I hope you don’t feel I gave you a bum steer with the magnet advice. I meant well, and have had good results in the past.

Hi Larry,

A very strong magnetic field in a square with a completely dead reed switch is of no use. If it is in "open circuit" (as it appeared to be) it can cause it to "wake up", though sometimes only for a while: obviously that reed switch is weakened. If the reed switch on the other hand is damaged and permanently with closed contacts (this did not seem to be the case), the strong magnetic field cannot make the situation worse. So I agree with you... your proposal was not unwise. Of course because you indicated "powerful neodymium disc magnet": Just saying "powerful magnet" could be dangerous according to some people's interpretation. LOL

Best,
Gerardo

[mychess]

Hello,

Super-strong neodymium magnets : do not see it after 2mn 10 s !!! https://www.youtube.com/watch?v=0t8yDnyOaQ8

Cordially

[X__Gandalf__X]

Hopefully there will be a happy ending. I hope you don’t feel I gave you
a bum steer with the magnet advice. I meant well, and have had good
results in the past.

It was good advice, and worth a try. Cannot expect good results every time.

[pawnzephyrpeaceful]

It seems like the problem lies with the h file, where the h1 light stays on and when the computer makes a move, an extra h light comes on. Based on what you described, it's a bit tricky to pinpoint the exact fault, but attempting a repair could be an option if you're up for it. Since you mentioned having limited experience with such repairs, you might want to consider reaching out to someone more experienced in the field who could help you troubleshoot and fix the issue. Ultimately, it's up to you whether you want to put up with it or give the repair a shot.