Eventide H-3000 no input no output HELP

[mappee]

Called Eventide and was told they no longer service H3000? My unit appears good as window turns on with all info,
changes parameters, and pgm's load...but no input shows on meters and unit has no output. Who repairs these classics
now that eventide has abandoned service on legacy product?

 

[guy_4]

Hello,

Are you able to check the different power rails inside ?
+5VDC for Logic, and +/_ 15VDC for Audio.
There are many tantalum caps for PS decoupling, and they often end their life as a short.
It can be tricky to find the bad one.

Best,
Guy

 

[mappee]

Hoping to find someone in NJ to service, I'm even going to call Dave Derr and see if he can help.
The unit is sitting about 3 miles from Eventide Little Ferry at moment so when I heard they won't
touch it my heart sank. I've looked at service manual online which is nice they post this info and
noting the A/D chip u15 is 28 pin soldered I am leary on self repair. My search is just starting but
maybe a DIY guy/gal can be of assist here. Thanks for reply.
1st looks like check voltages and have noted the many mustard tants. Some TL072 are socketed.

 

[soapfoot]

I had a similar issue and it was a couple of shorted tantalum caps on the power supply rails.

I ended up replacing every tantalum capacitor in the unit as a preventive measure.

It took awhile to find the faulty ones, but I did find them (even though I planned on the comprehensive replacement, I wanted to find the fault)

IIRC the 15v rails had 16v EDIT: 25v caps on them, which is marginal to say the least. I replaced all with 35v parts and feel a bit better

 

[living sounds]

IIRC the 15v rails had 16v caps on them, which is marginal to say the least. I replaced all with 25v parts and feel a bit better

Marginal... with tantalums that's near criminal...

 

[Ike Zimbel]

+1 on shorted caps as the probable cause. If you end up doing this work yourself, MAKE SURE you know how to remove parts from double-sided/multi-layer circuit boards before you start. You WILL damage the circuit board if you do not remove the caps properly. They should be de-soldered to the point where they just pop out of the board without any prying or other use of force. When you do take a part out, examine the leads carefully. If they look like they have a copper collar around them, you have damaged the board. At that point, you need to make a note of where the cap was located in the board and install the new cap with enough lead showing on the top side of the board that you can solder it from both sides. This MAY solve the issue, but it is much better not to cause the issue in the first place.

 

[soapfoot]

Yes, I almost edited my post to recommend buying or borrowing a *good* desoldering tool like the Hakko FR-301 if you can at all manage it. Replacing all tantalums in an H3000 is quite the rework job but totally worth it.

My unit was trash-picked and after shotgunning the tantalum caps it works brilliantly

 

[soapfoot]

Marginal... with tantalums that's near criminal...

Agreed. Referring back to my old thread I see I was mistaken—that it was actually 25v parts on the 15v tails and I used 35v parts in the replacement, on your advice.

 

[mappee]

Okay so after voltage check, culprit would be tants having affected multiple posters. Not much luck with
double sided boards here but I had a console reworked at fair price per cap and may inquire them.
Noted 35v. Thanks for shared experiences. H3000 25 years old or more so replacing caps reasonable.

 

[pucho812]

If you don’t mind shipping, bimish electronics in Ohio is awesome on digital gear from yesteryear. He has done wonders for folks I know. I highly recommend.

 

[mappee]

Eventide did suggest sending unit to Beamish in Ohio. Nice to see you speak highly of them.
Bit reluctant on shipping but it may come to that.g.
I saw Edgar Winter play and his synthaxe is continually cobbled together from 6 different units for his
Frankenstein finale. Who would think that old units would be so hard to maintain once
they become obsolete.

 

[flyingeyepro]

Beamish does great and has many unobtainable parts.

 

[mappee]

So here's current state of Eventide repair. By replacing the +/- 15/v regulators and a burnt tantalum unit showed input on meters. Output was digital distorted mess. Replaced the TL074's, D/A burr brown chips and left channel works well.
Right ch. registers on input meter but has no output at all?
I spoke with Beamish and they want unit sent to Nashville. Called Dave Derr and he was unobtainable, rats.
H-3000 close to working, need help to proceed? Looking for CMOS 7512dikn opamp