Emulator II- Only 7 out of 8 voices sound / 'E' keys are dead/ Output 2 is dead

[Myemulatorsite]

I hope someone can help me with this issue. 

I have an Emulator ll that was sitting unused for many years. I tested it out recently and all functions seem to be working.  However, there are only 7 voices. Whether playing the same key several times in a row or playing up or down the keyboard , the keyboard will only sound 7 times and then the next strike will be silent. Depending on where the 'voice rotation' is, the keyboard could sound 2 times then be silent for one note strike, and then sound for the next 5 times. 
Output #2 has no sound. All the other outputs work correctly as well as the mix output. Plus all of the 'E' keys are dead- Except the highest 'E' key.
When playing the Ell from another keyboard via midi, the Ell's entire keyboard is triggered without any problem or dead keys. But still there are only 7 voices. 
Attempted to fix by removing the power supply section and swapping the voice chips ssm2045 and s3528 from output 1 to output 2 and vice versa. Output 1 continued to work fine. Output 2 still didn't function. So those voice chips are all OK.
 Next I identified the chips below the voice chips that appeared under each of the other outputs. I then swapped those chips between Output # and #2. This produced a random type of voice drop out unlike the regular original dropout pattern.
Not sure what to do, how involved a fix could be and if I should bring it to a tech.
Would appreciate any help I can get.
thank you all

[dr.c]

Put back  the chips in place as they were originaly and please, stop messing..

Now, each channler has a chip referenced  S3528

Take the off, DO NOT SWAP THEM, clean their legs (I din't know how to say), and then put them back in place.

Be carefull with the pins (that's tha right name !) not to be bent, chip correctly oriented, and try.

[Myemulatorsite]

Hi.... thank you very much for your reply- I will try out your suggestion- hopefully tonight. I'll post my results. And no more messing around!!

[Myemulatorsite]

Hi dr.c
I removed, cleaned ( De-Oxit) and re-seated the s3528 chips under each of the 8 channels.It went smoothly, but I still have the same problem. It was worth a try.
Thanks for your suggestion.
If you know of another possible fix, I'm open to it.
Thanks again!!

[dr.c]

Interchange the S3528 from channel 3 and 2, do not touch channel 1 !!!

You will still have a non working channel, but did it become channel 3 ?

This is to confirm the eventual S3528 breakdown...

If confirmed, put back channel 3 in place and order two S3528 (a spare you may need one day).

[Myemulatorsite]

Hi Dr. c,

Thanks for your reply and help!

I Interchanged the S3528 chip between channel 3 and 2. But channel 2 is still the problem. Still no sound from output 2.
Channel 3 still has output.


thanks again for all of your help Dr. c!!

[alka]

could be another component in this particular channel. I might try swapping just the LF356 IC 51 from channel 2 to 3 and check for signal on channel 2 at this point and then perhaps the TL084 (IC72) next. Do one at a time as Dr. C advises. report back.

[Myemulatorsite]

   
Hi Alka,

Thanks for taking the time to post.
I swopped the LF356 IC 51 from channel 2 to 3 and the TL084 (IC72) chip but still have the missing voice and dead output #2.
I did Correct the dead 'E' keys by cleaning contacts under keys.
I believe I've swopped out ever removable chip from output 2 to 3 and still continue to have no output from 2. Output 3  continues to  function correctly after the swop.

Thank you very much for the help.
Any other suggestions are welcome

[alka]

so let's back up. are you certain your PSU is putting out clean voltages? have you checked all the molex connections coming to and from the PSU? My EII was acting very erratically including occasional missing voices because of wonky connections.

how are you testing for the missing voice? are you plugging an amp into each individual out and striking the key at least 8 times? Obviously the one with no signal is the voice that is giving you issues. Is that how you've ascertained Channel 2 to be the issue? and therefore it is also not present in the mix out?

[pdub]

Hi

Did you ever solve your problem?

I?m having a similar issue with my EII. Voice 6 is dead and I?ve swapped all chips on the output path with working channels but 6 is still dead. Power supply voltages are fine and I?ve cleaned all the sockets in 6?s output path.

Any help would be greatly appreciated.

Thanks!

[alka]

did you also try swapping the ls or hct 393, 273, and 08s in each channel to see if it's a logic issue?

[pdub]

Thanks for your reply!

Yes I swapped all the chips on the output schematic page including those.

I think I also have a bad 08 chip because it makes the two voices it controls loud and distorted. But still no voice 6.