Holy Smokes!

[jeffdavison]

Can anyone suggest where I can get my Eico 667 serviced?

It was working fine since I've had it for a few months, then today while testing some NOS 6550's it started smoking and not make nice smells at all.
The fuse did not blow! and I think it took the tube I was testing with it.

I'll open her up later when I get my mojo going and prepare myself for the autopsy.


Jeff Davison

[TomMcNally]

Hi Jeff -

I was just looking at the schematic for the 667 ... not much to it really.
A couple of diodes (if the one is Selenium - that may have been the nasty smell) and a few capacitors. I'd check them first. You could lift one end of each diode, then power it up with a tube in a socket (properly set of course) and see if the tube lights up ... at least you'll know the transformer is good.

... tom

[erichayes]

Hi Jeff,

It's hard to describe the smell of either a selenium rectifier or transformer gone south, but the transformer smell is a bit sweet. The rectifier smell is pungent and choking (and highly toxic).

I'd do as Tom suggested, but before popping a tube into a socket, let the transformer operate under no load at all--not even the pilot light. Check its temperature after about a minute; if it's cold, check it again after 5 minutes. If there's no change in temperature at that point, go ahead and put a load on it.

If it turns out the transformer has had it, don't lose hope. The majority of the tubes you'll probably be testing will have 5, 6 or 12 volt heaters . . . maybe an occaisional 2.5 volter. With a little ingenuity, those voltages can be created using "junk box" transformers, or a new Hammond with multiple heater windings.

In any case, you'll want to replace the selenium rectifiers with 1N4007s. It wouldn't be a bad idea to replace the electrolytics, as well.

Good luck

[EWBrown]

A burned out selenuim rectifier has a really nasty, acrid smell, think of it as being the "aerosol results" of someone having eaten about 24 pickled eggs and some pickled pigs feet the night before. :parp: :o

Transformers will usually have a "burnt motor" smell, and resistors have their own unique "electronic death" smells. Likewise, caps have their own unique sounds, and aromas when they go bad...

Not the most elegant technical terminology, to be sure, but this should be a good start for olfactory troubleshooting techniques. Yellow_Light_Colorz_PDT_09

/ed B in NH

[jeffdavison]

Got the 667 up and running again. Turned out to be a blown electolytic.

The last owner got rid of the seleniums and put in 1n4007s., but put replaced anyways with known good new ones.

I replaced the caps.. a 40 mfd / 150v to replace a 10 mfd an also a 22 mfd / 25v to replace a 10 mfd / 10v. (Suggestions from the "Tone Lounge" on their Eico 667 pages.

Once you really look at the schematics the Eico is very simple compared to the Hickoks.

Thanks for all the help once again!

Jeff