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?
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] wrote:
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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?
Well, one of my voices just died as described. Took it out, checked but it started to work again so impossible to trace the cause. Now when i have installed the voice card back it died again lol...
No output on 0 terminal (out) Now its really dead. I have traced the problem to the IC2 (the EG amp). It has no output. When i turn the VR17 more (initial level) the voice is sounding so I think the card is mostly ok...the problem is envelope / trigger related (TRG boards??). I will investigate more tomorrow.
one thing to check also on cs-80 ! if you slide the modules chassis up and down a lot ,,, check at the black wires junction that there is no broken or corroded wires or on the verge of breaking? ?. On mine moving up and down the rack a lot , the main? GND 2? black got broken? ( +8.5V/-6.5V ) .. so the supply lost ground reference ,,? the synth was working but the positive and negative rails were moving ( floating )? in parallel up and down moving the keyboard controls levers . That was a bitch to debug ,, it is not evident to see a broken wire at that location ,, there are so many grouped there .
for your problem : you have output on pin 8 of IC5/CP5? , but cannot control VCA/IC6? when triggered . Have you checked if you receive the trigger signal at TR(63) ( broken/corroded/cold solder ) . if yes? check your EG signal? scope/meter TP2 if yes them funky final vca IC6?
You seem to be in control of that bug , you are not far from a solution , nice work DUDE !? check for cold solder joint with freeze mist (were talking about heat related bug )?
remember that the trigger is for both voices so if the other voice is working it is not the trigger circuit .? check for trigger signal first , could be a corroded or broken wire ( white as i remember ????) so many colors .?
hoping IG00159 is good ,, there is plenty of VCA out there but way less IG159?
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On Thursday, August 16, 2018, 8:50:04 p.m. EDT, pyjamagroove@... [yamahacs80] wrote:
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Well, one of my voices just died as described. Took it out, checked but it started to work again so impossible to trace the cause. Now when i have installed the voice card back it died again lol...
No output on 0 terminal (out) Now its really dead. I have traced the problem to the IC2 (the EG amp). It has no output. When i turn the VR17 more (initial level) the voice is sounding so I think the card is mostly ok...the problem is envelope / trigger related (TRG boards??). I will investigate more tomorrow.
The CP5 is there, TR63 also but there is no signal from EG at TP2. There is no output at pin 3 of EG and nothing at pin 3 of IC2(VCA) and no output (pin 8 ) from it so no wonder TP2 is dead...to be continued..
I was thinking that there could be a cold solder joint somewhere because it reacted to the heat. So I did reflow the joints at IC13 and IC2 and around. And it worked! That's kind of stupid really but it did. Might be helpful for someone in the future...
Anyways thanks again ?for your help guys!
PS. Doug is appearing always out of the thin air if someone needs the chips lol. Good to have you! - And don't worry - I have checked your website in the beginning of this thread - just in case!
hey hey hey ,, your the man ! great debug job !? ?I think on mine i will remove all ic sockets ,? anyway the pcb is single sided so very easy to desolder with the proper tool !??
Thanks. I'm happy that it worked. I don't know is this a good idea to get rid of the sockets. With them it's easier to swap the chips between the cards to test them.?
pyjamagroove