Sick FS1R

[romain]

Hello guys,


Thanks to rasputin on this forum who gave us the schematics, i think i may have found the possible malfunctioning chip on my FS1R.

For a long time now, the user memory presets haven't been working well. Even after a factory reset, i get "@@@@@@@@@" for all the presets and after a while (and also randomly) my lcd screen starts blinking, i have problems playing notes, receiving midi information, transpose is at the maximum... Anyway, it's a big mess.

I discovered the service test mode with the schematics and apparently, there is a problem with the RAM (only once was it "NG" as in not good)

Do you think that the problem comes from IC2 (DRAM) and/or IC3 (SRAM) ? Is there a way to change those chips if i can find them ?

Or do you maybe have better ideas ?

I have already changed the battery and bought a EPROM with the OS upgraded but there's no change at all.

[sneakthief]

Did you check the psu voltages?

[romain]

Hi

Thanks for your answer. A friend checked and said that it was ok. But i will do it again when i get back the proper tool for that and tell you the voltages.
What should be the proper voltage mesures ? And what do you mean by psu (sorry i m quite bad with electronic)

[romain]

Hi again

I did the maesurements myself and where i should have 12 v, i get +11,92 v and -11,93 v

For the 5v, i get exactly 5v.

Do you think the voltages are ok or should i have exactly +12V and -12V ?

[madtheory]

Those voltages are fine. I really think you should refer this to a good technician. The FS1R is a very complicated machine if you don't understand "psu", and certainly worth the shipping and repair costs. If you want to learn electronics that's great, we can help you out with that. But an FS1R is not the place to start. Walk before you run

[romain]

Ok
Thanks for the answer.
Oh yes, i certainly don't want to start improving and practice my electronic knowledge with my FS1R. I have some friends who are very better than me but i don't know where to guide them to find and solve the problem.

In France, apparently its quite difficult to find a qualified technician who can manage this kind of gear. I tried to contact Yamaha and they told me to check companies who repairs washing machine and stuff like that ...

Anyway if you have another ideas guys, i would be very happy.

[madtheory]

Post a new topic asking for French synth tech. They are DEFINITELY around