Vintage Synth Explorer Forums

Hi everyone - I am new to the forum, so if I posted this topic in the wrong place... I apologize. Yesterday My 6400 started acting up, and now has no audio. The +15 and -15 LEDs are no longer lit. It boots normally, and all works, just no sound. I am leaning towards power supply, or one of the inline power components. Can anyone help point me in the right direction? I know my way around a circuit board, soldering iron, and meter. I fix pinball machines, but I know noting about the repair of these. And there are no technical hardware manuals/schematics.

In the meantime... I'm using my D-50 via MIDI and the V/PK

Help please and thanks so much!

Sounds like the power supply for the analogue section is dead.

If you're capable of safely working with mains voltages then testing and repairing a power supply would be the first thing you learnt; if you don't know how to test it then for god's sake don't go poking around near mains power, take it to a professional before you electrocute yourself.

Hey There and thanks for the reply. Power supplies for Video Game Arcade machines is one of the first things I learned how to do (so maybe that's good) Can you point me to where that Power Supply is ?

Thanks !!!!!

Near the power cable input would be a good place to look

Heh ! Well the power comes in and goes to a number of terminal blocks in the front and back of the system. There are at least 4 power supplies in the unit. I think I know which ones are powering the disk drives and the processor, but there are two others. One up close to the top in the front, by the MIDI/STM trays, and one in the front of the machine on the lower left. That last one I mentioned seems to be the most likely candidate. I see a BIG step down transformer, a diode bridge, and a power board (wired to the front panel voltage indictors. I'm guessing it's that one, but if some synclav guru could validate my suspicion - I would greatly appreciate it. I almost nver see transformers blow, but I guess it cold be that. The bridge rectifier would be the most likely to me, as these are the first things I replace when I am having power problems for Pinball repair.

Need help here dudes Thanks

OK - I think I know which power supply is the culprit, but If I can find a place to source it... then I can get my system back up, and work on the bad PS on my workbench, and work on it at my leisure.

Does ANYone know where I can get a replacement for an Acme Electric SPW 15-5 and SPW 15-.8?

any leads would be much appreciated.

Thanks !

I've never dealt with them, but on the west coast of the USA are:
http://www.synclav.com/NED-systems-home.html

I have dealt with Chris and Ed, who are on the east coast,
917.254.7301
Chris is ebay seller CJM7
I can't find a web site for him.
It's my understanding that Chris and Ed worked at NED back in the day.

Great Leads - Thank You.

I got brave last night and removed the Power Supply in question, and things did NOT get any worse, so I think I have successfully troubleshooted the issue. I rang out the Bridge Rectifier and it's good, so looking more and more like the step down x-former.

I also believe I have located a source for the power supply, so I'll keep you all posted !

Stay Tuned !

Hi Everyone,

I know it has been over a year since I started this thread, but I wanted to follow up with you all and close the loop.
I was back up and running again by 10/24/13, for a total of ~ 3 weeks of "downtime", and fully operational (with 100k sampling back up) by 11/4/13.

SO SORRY for the long delay

The main problem I was having was the +/-15v Linear PS was "blown". Once I located a replacement, got it, and wired everything back in, I then had power to the Poly Bin, but I was still having problems (weird sound/voice issues between FM and Poly - long story).

After some frustrating troubleshooting, I discovered that one of the Analogic daughter cards was also bad/blown, and If I simply took it out. I had everything back (except could only sample at 50k obviously)

I sourced another daughter card from a nice chap in England ($$$), and life went back to normal.

I am wondering though, how common is it for these Power Supplies to blow out like that ??? And why did I also lose a digitizer in the process???

Questions may turn out to be rhetorical, but thought I'd ask anyway.