CS50 Power Supply wiring question - ACK!
So i was stupid i admit and maybe didn't take the precautions i needed to - in doing a power supply rebuild i only took macro documentary pics and not an 'overall' - but i THINK i got all the wires right - it would be heartbraking after having spent the last few months rebuilding this power supply to blow it up when turning it on again to test it ...
so the question is ... "do i have the two longer orange wires you see in the foreground going to the right places?" - there are two possibilities only ... either as they are now or the reverse order??"? (note the splices in the wires)
I checked clues like the printing on the wiring but both run in the same direction and are cut at the same place on the printing sequence ... (ugh) ... i've gone through the schematic several times and i'm just not confident enough about it ...though think i may have it right ... the leftmost orange wire comes from the collector of the 2SD234 and the one to the right comes from the 2SA745.
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Re: CS-50 Portamento/Glissando problem
You could try SST Rentals in Nashville, they may even have a 50.?
Switched On in Austin could either sort it out or point you in the right direction.
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On 22 Sep 2018, at 6:52 am, sneakyflute@... [yamahacs80] < yamahacs80@...> wrote:
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Hi - right now I'm in Germantown, NY, but I'm on route to Nashville where the tour starts. Then Texas... maybe a tech in Austin, Dallas, or Houston could help? Know anyone?
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Re: CS-50 Portamento/Glissando problem
Thanks so much David. I'm sure I can find a Frys - or do a mouser order with quick shipping or something. I'll get some 4016 ICs. Do you think it could also be the 4069 (IC 23) or one of those two 4558 op amps (IC 21 and 22)? It now seems to be on two voices (maybe both had the issue before and I didn't notice). Thanks!
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Re: CS-50 Portamento/Glissando problem
Hi - right now I'm in Germantown, NY, but I'm on route to Nashville where the tour starts. Then Texas... maybe a tech in Austin, Dallas, or Houston could help? Know anyone?
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Re: CS-50 Portamento/Glissando problem
Hi.?
Looking at the KAS schematic, I’d guess it’s likely IC 9 or 10 - 4016 quad switch. Since the CS50 only plays 4 notes, I think IC 11 and 12 are not installed. ? I’d try removing IC9 and 10, putting in 14 pin DIP sockets and then putting them back swapped. ?If one off them was the problem, then the broken voice should move to a different one of the 4 voices. These chips are still pretty common so you can buy them but the only physical stores with them would be old time electronic supply shops or Fry’s. Sometimes I miss Radio Shack!
Good luck,
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On Sep 21, 2018, at 5:15 AM, sneakyflute@... [yamahacs80] < yamahacs80@...> wrote:
Hi. I'm on tour with my CS-50 and one voice suddenly is stuck on Glissando (I can't switch it to portamento). I need to fix it fast before the next show...
I only have a meter and soldering iron (and limited knowledge and skills :) with me, so I'm hoping to just quickly swap in some new parts (can't do much testing).?
Is the issue likely to be the comparator IC (the 4069 inverter) in that part of the circuit (IC23), or is there something else I should target? Again, glissando works - so maybe the gate is stuck on?? I would like to try to make one stop or one order for parts before I attempt to do this, so it would be great to hear some of your guesses so I can get those parts before I go in.?
Thanks! DT
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Re: CS-50 Portamento/Glissando problem
Where are you??
Could be a tech nearby...
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On 21 Sep 2018, at 10:15 pm, sneakyflute@... [yamahacs80] < yamahacs80@...> wrote:
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Hi. I'm on tour with my CS-50 and one voice suddenly is stuck on Glissando (I can't switch it to portamento). I need to fix it fast before the next show...
I only have a meter and soldering iron (and limited knowledge and skills :) with me, so I'm hoping to just quickly swap in some new parts (can't do much testing).?
Is the issue likely to be the comparator IC (the 4069 inverter) in that part of the circuit (IC23), or is there something else I should target? Again, glissando works - so maybe the gate is stuck on?? I would like to try to make one stop or one order for parts before I attempt to do this, so it would be great to hear some of your guesses so I can get those parts before I go in.?
Thanks! DT
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CS-50 Portamento/Glissando problem
Hi. I'm on tour with my CS-50 and one voice suddenly is stuck on Glissando (I can't switch it to portamento). I need to fix it fast before the next show...
I only have a meter and soldering iron (and limited knowledge and skills :) with me, so I'm hoping to just quickly swap in some new parts (can't do much testing).?
Is the issue likely to be the comparator IC (the 4069 inverter) in that part of the circuit (IC23), or is there something else I should target? Again, glissando works - so maybe the gate is stuck on?? I would like to try to make one stop or one order for parts before I attempt to do this, so it would be great to hear some of your guesses so I can get those parts before I go in.?
Thanks! DT
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Re: CS80 Vanishing voices mystery
yes for sure it is practical . And removing all those sockets? waaaaaaaaaaa ! Don't fix it if ain't broken as the old folks said !? ciao !?
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Re: CS80 Vanishing voices mystery
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.?
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Re: CS80 Vanishing voices mystery
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 !??
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Re: CS80 Vanishing voices mystery
Well. Good news.? 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!
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Re: CS80 Vanishing voices mystery
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Re: CS80 Vanishing voices mystery
Prices are listed on my site -?
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Re: CS80 Vanishing voices mystery
I have the IG00159 EG and IG00151 VCA in stock if you need one.
Doug? synthparts.com
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Re: CS80 Vanishing voices mystery
Thanks Nicolas. 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..
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Re: CS80 Vanishing voices mystery
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.
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Re: CS80 Vanishing voices mystery
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.
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Re: CS80 Vanishing voices mystery
Thanks Nicolas but no. I tried that.?
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Re: CS80 Vanishing voices mystery
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?
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Nigel99
pyjamagroove