Yamaha CS80

the vcos are  on  sockets ! try cleaning the pins ,, just beware of static , you could do that with all socketed ic on the voice board ,, .  most of the problem i ad with mine was due to that problem . 
good luck hoping it is just that !
    On Monday, August 13, 2018, 11:55:06 a.m. EDT, pyjamagroove@... [yamahacs80] <yamahacs80@yahoogroups.com> wrote:  
 
     


My CS80 had this problem for some time now and I'm starting to think it might be heat-related.

So some voices tend to randomly go dead especially in the bank 1. It is difficult to diagnose because when I take the card out to inspect they sometimes come back....When I screw the card back sometimes they go dead again. Also when I leave my synth on ant it's hot some voices die and come back again when cold..... I live with it but I would like to get rid of this issue once for all. Did you guys had the same problem before? Maybe it is not M card problem at all but TRG board for example?