Traynor YGM2 smells funny

[Haaky]

Hi guys new here looking around nice site.

I have a problem with my YGM2. A guitar buddy was playing it when i could smell something burning. Sure enough after i took it apart there was a burnt resistor.

This amp has a couple of mods done to it.
It's had a cap job. Bias pot installed, i believe a tone stack mod using the ground loop switch (sounds wicked)
And the volume pot replace with a push pull to add a boost.
I really can't afford the $200 it gonna cost to have it looked at. I'm sending a couple of pics so you guys can hopefully steer me in the right direction.

I was told that a power tube probably shorted out.

Now i want to replace the resistor and the output tubes. I'm sure that it will have to be re-biased. I'm just not sure now how to do it because of the mods

Any and all help would be greatly appreciated. I do feel comfortable working on my amp so no worries there.
If you need more info or more pics just let me know. Sorry about the fuzzy one

[guitician]

Take out the resistor and measure it. Those CC resistors can burn like that and come back to the same value. It will be either 470 ohms or 4700 ohms which ever is closest. If you look at it with a magnifier you may be able to see the color of the third band. The wattage looks like 3 or 5 watt. If you install the same type tubes you can run on the same bias setting at first, then decide if all is well(no red plating).

[52 Bill]

Welcome to the board.

Originally Posted by Haaky

I was told that a power tube probably shorted out.

Possibly true. Does the amp work now that it has cooled down?

Originally Posted by Haaky

Now i want to replace the resistor and the output tubes. I'm sure that it will have to be re-biased. I'm just not sure now how to do it because of the mods

I'm not sure, but it looks like one of the mods done to the amp was to install 1 ohm resistors on the output tubes. If this is so, biasing will be easy to do with just a voltmeter.

This amp has EL84's in it, correct? Look at the two resistors on the output tube sockets. Are they attached to pins 3 and then to ground? If so, you can measure the idle current across these resistors.

As for the burned resistor, that appears to be in the screen grid supply. It looks like a 2 Watt 470 ohm resistor.

[Haaky]

The funny part is i could not tell what the 3rd band was. I tried 2 different magnifying glasses. But when i took the picture, bang it was easier to see just enough of the third color.

Old eyes

It's a 470ohm i wasn't sure what the wattage was though. The place i buy my stuff from will know.

I'm hoping it's just as easy as replacing the resistor and the tubes. Only one way to find out. I still have the old tubes i can try. I beleieve they are the same brand.

I'm just noe sure on checking the plate voltage because the the bias pot that was added. Not sure exactly where to place the probes from the multimeter.

[Haaky]

Actually i haven't tried it since i've had this problem. It's been sitting on my workbench for the past 2 weeks.
I should try it and see. It should work. It worked fine the night it blew. The only reason i knew something was wrong was because of the smell. The amp sounded fine. Of course i was drunk so anything would have sounded fine

It looks like there 1 ohm restistors
Yup 2 EL84's with resistor connecting pins 3 to ground.
I figured it was a 2 watt took some time to figure it was a 470 ohm. One band was almost completely burnt off.

[Haaky]

This isn't Wild Bill from Hamilton is it??