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I just purchased a Double Cherries machine - 1995 and it is a Sigma SG-150. When we plug it in all display lights work but LCD display does not come on nor do the buttons light up. After about 30 minutes plugged in they all came to life. After playing the machine for 5 minutes, (the machine worked perfectly) the LCD display and buttons shut down and did not work again. It has been doing this most of the day. Tried checking wires and connections for frays, etc. Can't figure out what the problem is. Would appreciate any help/advice you could offer.

:238-  vmraddatz :88-

First, I don't know much about the Sigmas, but it sounds like a heat-related problem. A component on the MPU board (or elsewhere) is probably heating up and failing. Tracking that sort of thing down can be time consuming.

Typically, you have to identify the general area with the bad component and then use freeze spray on one component at a time to isolate the bad part. There could also be a causal problem that must be rectified as well, but I'll let the electronics hardware experts take it from here. :131-

If we can isolate the problem to one board, you could also just replace it rather than trying to find the specific component, but at this point that's premature.

StatFreak :31-
:nlg-  Global Moderators

Thanks  I will cool it down and see if that helps

You already have -- by turning it off for 30 minutes -- and it then failed after being on for 5.

We need someone with more Sigma knowledge or with more electronic component diagnostic knowledge to help you figure out where the failure is likely occurring, OR you could try spraying parts of the MPU board to try to shotgun. There is also a chance that it could be a power supply problem. If so, it's also probably a heat-related failure.

I'm not certain but I think the problem is a cold solder joint on the Display board.
It also could be the ground pin on the power connector going to that same display board....
clean the male and female connector pins with some de-oxidizing spray or sandpaper.

My SB50 did the same exact thing and I fixed just by unplugging every connector I could find and re connecting.

 My sigma 300 machines have the same board as yours.
It sounds like it may have a bad connection.
I would also start by unplugging, and plugging in your mpu connections.
Sometimes just getting a new fresh connection is all it will take.
I have to do that occasionally with mine.
Check out some of the other threads on these machines,
Good luck!