Troubleshooting old gear that used to work: 1176-not a clone

I have an 1176 blackface, that I decided I would use yesterday after not having used it in a long time (I don't particularly like them...yes I'm that one person).
It was fine for about 20minutes, but then it just shut off! So I took off the cover, couldn't see anything blantantly wrong like a burnt resistor/capacitor/etc. The Power transformer however, was HOT! I let it cool, and tried powering it up again. Same thing, worked for about 20minutes, then shut down making a soft "clink" sound. Nothing burned, regulators were working fine, etc. The only problem I could 'see' is the power transformer getting burning hot. The fuse didn't blow so I guess that would mean it's not drawing extra current from the wall?

Any help, much appreciated!

Are the power rails (+30/-10V) alright when it's working?

is the meter full right??

I had a similar problem and had to change some of the big electrolytic caps

ti wasn't set for 117 and not 220 ?

Turns out I'm not getting correct voltages at the Vreg. I did smell something burning but I couldn't distinguish what it was, I just shut it off to minimize potential damage. I didn't have a chance to measure voltage before the regulator (should I power it back up and try?). How common is it for Vregs to die (does it become a dead short when it does die?).

Thanks!

Depending on which revision it is, does it have the 3-pin V-reg or the stud diode for the +30V?

I've had a stud diode in an old Rev. D 1176 die hard-short circuit. The tranny got nice and toasty when that happened! (so did the big resistor! :shock: )

Other than that, you can see where too much current is being drawn by lifting wires and sticking a current meter (fluke set to 'A' with the lead in the other hole... DON"T FORGET TO PUT IT BACK AFTERWARDS!!!)

Keith

[quote author="Ethan"]The fuse didn't blow so I guess that would mean it's not drawing extra current from the wall?[/quote]
No, if the transformer gets too hot, then it is drawing more current from the wall. But that fuse is not there to protect the equipment - it's there to protect against fire. So you will need a very hot transformer or a short circuit to make the fuse blow.

Best regards,

Mikkel C. SImonsen

Ethan,

Hi! you are not alone. I am the other person! They are not my fav's either. i guess that kind of admission is tantamount to suicide 'round these parts. Apart from my general dislike, they are all different IMHO. No consistancy at all! i guess that is all the different revisions. And different adjustments. Worst offender imho is the new "Re-issue". Purple Audio is better, and much more predictable, but still not there for me. I was lent a Chinese copy to try. Cost only a couple of hundred quid. Absolute Pants, I'd say! Haven't tried any Clones from this forum tho'. I guess i was spoilt when i owned the current 1176's Daddies, Teletronix 176. Now THATS a wicked compressor, even tho' it went wrong all the time! I had to adjust it before every session to prevent "thumps". Cast me a fortune in the repair shop!

It's not that they are bad, and it is my view that there is no such thing as a "bad" compressor. Even the humblest crap can be used to Mangle dirty loops etc, but They(1176's) just leave me COLD.


Each to his own, 'n all. Thank Gawd we don't all use the same gear, or everything would sound the same . . . . . (er - just a minute . . . . .. )


Blah,

ANdy P