Stereo output troubles strike new user.

[JonWest]

Hello all,

Hoping for some enlightened feedback although unenlightened commiseration is also appreciated.

Got an EIII rack, old analog version. It's in pretty good shape but has always been a little flakey about the stero mix out. It used to be that if I opened it up and reseated the second cable away from the stereo outs on the output board it would work reliably for months.

Then I made a mistake...I picked the EIII up and moved it to a different room. I immediately lost the stereo out. Woops. I reseated the cables and it came back...for about a week. Then I noticed a cycling high pitched whine sound coming from inside the case. Sure enough this sound was the announcement of an impending work strike of the stereo mix outs. 

I could get the mix out back for a few minutes by reseating the cables, but this is an increasingly ineffective fix. I tried to up my game by using some contact cleaner and bending the header pins just slightly and after doing that each time it'll work for about 30 minutes before the whining starts and the mix out cuts out.

I should mention that the whining sound is certainly coming from the yellow plastic box immediately behind the mix outs. I'm presuming this is the relay that some of you have mentioned can be trouble. ALso of note is that the extra voltage hack to the IC right next to the mix outs seems to have been done to this machine as there is a small wire running from that IC down to where power enters the card rack.

I'm open to all advice. 

Thanks in advance to all!

[JonWest]

Another data point if it helps. I measured the voltage on the pin of the IC on the output board that has the extra wire hack (which I presume is providing extra voltage) and I got 4.6 volts. Maybe that should be 5 volts and I'm not getting enough juice from the power supply?

[who]

No enlightened feedback, but I got to go see my EIII at the shop today and it is now working.  I should get it back this week!!

There is hope.

[JonWest]

Congratulations on your repair!

What got fixed and where did you take it?

 

[JonWest]

I just found the EIII articles on DVDBorn's site. Looks like I need to do a power supply trim adjustment to get that voltage up to 5.05V rather than the 4.6V it's at now.

Still hoping that someone can double check my thinking on this before I risk electrocution or a fried EIII messing around with the power supply. Those capacitors so look big and dangerous......

[rectape]

Hey guys,

Any update on this?

I?m having the stereo output problem right now.

Thanks

Franck

[Naiplak]

same with me, and a high pitched rattle noise just before voices are gone. After some time it comes back.
How do you adjust this power supply voltage?

[ACEOFBASS]

same with me, and a high pitched rattle noise just before voices are gone. After some time it comes back.
How do you adjust this power supply voltage?

Once inside the Eiii,
Start by disconnecting the power supply outputs from the mainboard.
Use a DVOM to test the +5Vdc rail. 
Adjust the trim pot on the power supply for 5.000 v +/- 20mv

Do not, as some others suggest, set the voltage above 5.00 v

It is wise, to remove the single turn trim pot, and replace it with a higher quality 10 turn trimmer.

PM: me if you want instructions in deeper detail.

[Elmbeatz]

....
PM: me if you want instructions in deeper detail.

Hi ACEOFBASS!

I did send you a personal message, but I'm not sure if it got through to you, as it's not in my outbox... So I thought I'd reply here, nevertheless.

I also have this stereo output issue, and I think I should do the readjustment of the power supply. As I'm no tech or electrician, I surely could need some advice here. Could you guide me through this procedure somehow?
Thanks a lot in advance and greetings,
Elm.