Vintage Synth Repair

Well, I sent my Arp to a repair guy.  It came back and it worked for about an hour.  I went 
upstairs, came back an hour later and same thing, "extremely low output". Heres what the 
repair guy did.  "repaired caps in audio path around filter, lubed and cleaned 
switches/sliders, reflowed solder connections around ADSR path, cleaned audio 
connectors".  I can hear the filter working, The ADSR is also working as I can hear the 
attack slider working too.  Could it be something in the output section or something? I've 
noticed that the Odyssey has quite a hum/buzz to it even when it is turned off.  The Buzz 
goes away if I take the power cable out but otherwise is still there even when unit is turned 
off.
Also, the lights in my house often drop down suddenly when things like the washer are 
running, could these small surges of power be messing up My Odyssey? Blowing those 
caps around the filter?  
I have all new sliders from that guy in the UK, they seem kinda cheap but hopefully they 
will work for long time. Thanks list!
Dylan Nau
Mpls, MN


> I'm wondering if the envelope generators are firing.
> 
> Try manually changing the VCF cutoff frequency and see if that changes
> the sound heard when the VCA gain is up.  If so, the filter is working
> and it may be that the EG's aren't being triggered, which takes you to
> the EG's and to whether or not it's simply no gate or no trigger from
> the keyboard buss.
> 
> ARP filters are sealed units and are not subject to easy component
> replacement.
> 
> And, when I suggested listening to the Test Points in the manual, I
> actually meant listening to them.  Shunt the output of the audio test
> points (not the CV signal ones) to the output of the Odyssey and see
> where the signal drops away.
>