Beiträge von BGeri

Hey, could you solve the problem regarding the display? Does the machine work besides the display, like sound, lights, or the matrix? I usually repair newer Compumatic circuits but the architecture and way of powering the display are more or less the same. The software is intact in most cases, the only thing that can go wrong is when the circuit board itself is damaged. Can't really see on the photos but there are 4 diodes (D17-20) above the accumulator; under the accumulator (and above the 2 ULN2803A ICs) there are 3 ICs (again, can't see it on the picture but its likely that those are 74HC273N). The rightmost (if you orient your circuit the the accummulator on top) IC's 2nd, 5th, 6th, and 9th, pins are connected to these diodes and the MC14514BCP chip - you should check these connections first. If this isn't the issue, then shoot me a message or reply to this forum, and we'll go over the next possible error.

Hey, have you managed to solve the problem? If I'm guessing correctly, it might've been a faulty wire that was causing it. If it's already solved, please send me a photo of it. I'm eager to know.

After the text compumatic mtx 2-02 there should be the version of the software (for example: Varidar 2 48) while the "I feel good" is playing. The software probably doesn't even get to this state. Either the program Epron died or something is blocking it. All the wires should be unplugged, except the speaker's, and try to plug them back in one by one to see if one of them is making it unable to work. If our vending machine still won't operate, then maybe the REF34 IC has the problem. Or maybe the power supply is under 5V.

How weird. However, I still think that the problem is near the 4514IC. If you could post a Youtube video of it being turned on and the problem, I would take a look at that. Do the 1-3 pins of 4514 have connection to the IC's (HD74HC273P) 15, 2, and 5 pins beneath the rectifier. I can see the that the factory accumulator had been soldered off. This only occurs when it completely breaks.

Hey there!
Sadly, I have encountered lots of these boards, the main problem usually is with the accumulator, more precisely, when the acid leaks out. It's not that hard of a fix. The acid can damage the printed circuit and it doesn't necesserally mean that the chips are broken. From the 8 lines 4 are not working. This can mean that 4 wires are etched by the acid. On the right side of the accumulator, the IC's 12th pin is GND, 4-11 are the pins for the lines of the display. In Hungary the problem can be solved for about 70EUR. Perhaps, there may be something else wrong with it, but all the different kinds of problems with the display can all be fixed. It's not easy to determine the cause, but if u have it in hand it might be much easier to find out what is really going on.