Real trouble with roland promars

Hey you guys, I’m new here, just created this account for this. I’m from ceará, northeastern brazil desertic godforsaken
land. I have found a roland promars here, crazy cheap, the guy who owned it thought it was just a little weird old keyboard. But of course it doesn’t function, when i turn it on, only the filter sounds, no oscillator sound. It’s in really bad shape, I know nothing about eletronics, and I’m thousands of miles away from anyone that could help me and have very little money, i actually though i would die before even seeing something like this. What do I dooooooooo???

Unfortunately, I don’t think you’ll be able to get it working without knowing electronics. If you are not hearing the oscillator, then you have to start doing signal tracing - is the oscillator circuitry creating the signal? If so, where is it getting lost? There are many, many possibilities, and you will need things like an oscilloscope to find the answer.

The culprit may be a single tiny component - all the work is in finding out which component that might be. So I think that somehow you will need to get it to a repair tech.

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If there is really no hope of finding a tech in your area, one other thought is that perhaps you could trade it for a working synthesizer. We take broken synths as trade-ins - but then the shipping costs are likely to be very high…

Sorry, I wish there were better answers for you!

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Thanks sam, I’m working on finding someone to help me track it’s problems. And if not I’ll try to trade it

sometimes removing and reseating the oscillators chips will do the job. Be very careful not to bend the pins and to put them back in with the correct end to end orientation. That’s great news actually that the filter works proving that the unit has only a few problems starting with the sound source (oscillator)

I am sorry, but there are no “oscillator chips” in the Promars.

The Promars as the JP4 are very depending on the functionality of the sliders. If a slider or switch does not work, then the CPU will read the value of the slider/switch which was scanned before as the next value.

My recommendation to you is: sell the Promars to someone, who has a chance to repair it. Even it is not working, you will get an decent price. A pristine Promars sells for US $1500. A not working will still return around $500 - even if the shipping is another $100.