Traynor trem problem

[drewl]

Got a Traynor yrm1 that probably has a bad photocell.
the side across the intensity pot only measures 4.7k ohms, so when you turn up the intesnsity it kills the output signal to the master pot.
Anyone know what the photocell should measure?
I have another traynor cell that measures about 10k and yeilds the same result.
Am I missing anything or is it simply a bad cell?
Thanks.


http://schematicheaven.com/bargainbi...aster_yrm1.pdf

[52 Bill]

Let me ask the obvious question here: Are you measuring the PhotoCell resistance with the amp on or off? If the light bulb stays on, even a little bit, it will cause this problem.

I'd try replacing it with a Fender style unit.

[Don Moose]

You can try wrapping the 'bug' in some electrical tape and make sure it's light-tight, then measure the R side with the amp OFF.

It should be at least several hundred K-ohms.

If the extra dark fixes it, there was a light leak. Otherwise, you may need a new bug. It might be useful to set the speed to minimum and watch the voltage across the neon side of the bug - if it's stuck high, then you have an oscillator problem ... but you almost certainly have a dead bug.

Replacements are available from Weber, Hoffman, and a bunch of others - about $9USD.

[drewl]

great, will do and thanks guys.
Funny, but I've never had to fix/replace many of these in my years.

[trood]

Same problem

I'll check out these sources, hard to believe people are still making optos with neon lamps.

[52 Bill]

There are still a million guitar amps out there that use these neon based units. As far as I know these are being made just for use in the guitar amp market.