Oberheim OBXA memory problem

synthartist69 · Feb 20, 2012

Hey guys, I could use your expertise here

I am having a friend who is an electronics tech, run through the calibration procedure to get the OBXA working right. So far, after doing some work in the power supply he finally has the voltages where they should be. We are now stuck on trying to save patches. We have a new lithium battery...( we replaced the old with a socket and a CR2032. The OBXA will not take a patch load for some reason, we have tried several different levels and ways of doing it. I am very experienced with doing this on other synths as well. So we programmed a patch from the patch book and stored it on A1. If you turn the OBXA off and back on, the patch is still there. If you push another patch button and go back to A1 the patch is now garbled sounding. You have to turn off the OBXA and turn it back on to get it sounding right. So, this sounds to me like a problem in the Eprom chip??? If this is the case, where can I find a replacement for that chip? Everything is working on the OBXA now that the power supply issues were resolved. All 8 voices, all buttons, and knobs, etc. The only problem besides the memory is that one or two of the Oscillators are a little out of tune. I don't want to go further into the calibration until the memory problem is resolved. Any of your ideas or thoughts would be very much appreciated! Thanks!

Jim

Nele · Feb 20, 2012

Have you tried storing a patch into the other memory positions? A2, A3, A4.. etc. And does the problem still exist?

synthartist69 · Feb 20, 2012

I will try that tomorrow and let you know what happens. Thanks for the reply!

synthartist69 · Feb 21, 2012

Nele said:
Have you tried storing a patch into the other memory positions? A2, A3, A4.. etc. And does the problem still exist?

I tried this but still had the same problem? Eprom issue? If so, is there a place I can get replacements, or a place I can send the circuit board that may have an OBXA on the bench that they can test it with?

synthartist69 · Feb 22, 2012

Nele said:
Have you tried storing a patch into the other memory positions? A2, A3, A4.. etc. And does the problem still exist?

Basically, it will store a patch into say A1. But when you write a patch to another number such as A2 then A1 gets erased. If you turn of the OBXA and turn it back on it still remembers your manual mode settings...

Any chance the encore midi would help resolve this?