Ensoniq VFX SD problems

Hi there. My Ensoniq VFX SD wont save anything when I turn it off. Changed the battery a year ago. Makes me reload the sequencer every time I turn it back on. Plays all the internal sounds fine but when I plug in a MIDI cord (MIDI out) to trigger VST’s it makes a bunch of noises when playing the internal sounds and gives error codes 129 and/or 127. No problems playing the VST’s, just the internal sounds.

When did this start?

Having to reload the sequencer every time sounds like a battery issue, but I’d expect to get a battery low message.

Have you tried a hard reset?

Thanks for gettig back to me. It does sound like a battery issue but I changed the battery about a year ago after I started getting the low battery message. It wouldent save before that either. I didn’t use the keyboard for about 5 years before that. I load the sequencer from the disk and it works fine until I turn the keyboard off and start over again. Also makes terrible noises when I play it with a MIDI cable in MIDI out. Triggers VST’s fine though. The battery was installed the regular way, straight on to the board. I’m not a great solderer so maybe I did something wrong there.

It’s been awhile since I replaced the battery on my SD-1. I don’t think the contacts were close enough to be worried about a bridged connection.

My only thought is that the new battery could have been weak. You could still measure it with a meter. But I’d think it was fine if you’re not getting a low battery message anymore.

The tests in the service manual read like normal operation. For a failure like this, they point to a problem with the main board or power supply. I don’t understand why the power supply could be at fault, but it would be a good idea to test that anyway.

My schematics for the VFX aren’t too good. I found the battery: It looks like the positive side runs off to another page where I suspect there’s a circuit to test the battery level. But there’s a diode (CR2, 1N34A) that connects the battery to the RAM. If that diode were to fail, I think you’re battery would still test okay without maintaining memory. Without the VFX plugged in, you should measure battery voltage (+3v) on pin 28 of either RAM chip U9 or U10.