I know, but I think those recent questions asked by JM were directed at the other guy (DHKV69) who jumped in on the discussion.  My amp is not sqealing, so I cannot get it to go away, there is no difference when I adjust the tone control and as outlined in my first post, I have tried nothing short of a billion guitar cables.  I have rattled and swapped the cables going to the cab from the head unit as well.  Just a tiny bit of sound.  The sound switches from clean to distortion when the appropirate channels are selected on the footswitch and/or the head unit but when turned all the way up, it's barely audible.  Also, the only switch that seems to make no difference whatsoever is the master volume control.  I tried to remove it for continuity/resistance testing but the contacts seem to be soldered directly to the circuit board.

Well, it's been a while since I posted, I've been trying out the solutions that JM gave me but to no avail.  I am having a hard time following the power flow (tone signal) through the amp circuit board.  Anyhoo, at some point, another forum member (DHVK69?) jumped in with a different problem, seems there may be some unanswered questions in his case.  If there are any questions either JM or anyone else needs answered or any I may have missed, I'll answer what I can. 

Well, I have given it a shot.  I tried sending a tone through the amp, I've tried diagnosing it with a short circuit tester, I have gone over the circuit board with a comb, I just cannot figure it out.  I can't seem to follow the pathway of the signal of the tone.  On the opposite side of the the housing from the internal circuit board is a large, heavy thing wrapped in windings.  What is this, could it be bad and is there a fuse anywhere I need to check?  Is there a way to test the continuity or the resistance in this thing?  Just seems like my sound is there, just not amplified.   xP

Thanks, JM.  I've got a ton of work to do so I guess I'll get on finding that MP3 file or something similar and riggin up a cord.  I have doubts that the schematic I found is the schematic for my particular amp, but hopefully both of the schematics can lead me in the general direction.  Randall wrote me back and said "Uhhhhh, take it to a repair center  -n-stuff..."  So no schematic from them.  I guess we'll see how it goes!  I wonder what the difference between the RG and the RH is.

This is as close to a schematic as I can find.  I have written Randall and requested a schematic, I don't know if that'll work out for me or not.  If I download the MP3, make the cord and supply it to the amp, what kind of voltage will I be looking for to know that it's there or not?  Also, on a side note, do you have any idea how to remove the separate pots on this amp without cutting the entire circuit board loose?  I have the knob pulled off and the small nut and washer off but I don't see how the pot is actually supposed to release from the board.

Well, I snuck home @ lunch time hoping for the best but found that plugging, unplugging and fiddling around with the send, return and headphone jacks all yielded no results. Same thing, a couple decibles of sound, they change according to what channel I select and the sound goes away if I turn down the gain and sub-volume knobs. Still the master volume switch is unresponsive and looks like a trick to replace. I do have tools, a DVOM and other resources if there is somewhere I need to check for power or a switch or knob I need to jumper or short to eliminate. At this point I may have folded but the last person who ran a repair business in Fairbanks moved away. I'm learning a lot though so this is probably the best route for me to take.

Right on, thanks for responding.  I'll try it tonight.  You're saying to just take a good cable and plug in between those two jacks, leaving the cab plugged into the main out and the guitar plugged into the main in, right?  What should I expect to happen?

I am having an issue kinda similar to this one.  Have you tried a different guitar and swapped cords?  Your amp is a solid state, right?  Other than those basic things, I am not qualified to give much more info but I'm going to keep up on your post and hopefully find something that can help me with my deal as well.  Good luck! 

Hey guys.  I don't know if this question is getting the right exposure in the Newcomers section so I figured I'd try it over here.  This is basically copied and pasted from my first post.

This is my first post and as you may have guessed, I came here in search of an answer to my problem.  I have a Randall RH100 head powering a cab with 2 Carvin Brittish series 12s.  I have used it very little but a couple days ago when I went to power it on, it was making no sound.  I swapped guitars and still nothing.  I swapped probably 4 or 5 cords and still nothing.  Made sure the guitars were turned up, plugged them into another amp, etc.  Something is wrong with the Randall and I can't quite track it down.  I have noticed with the guitar turned up all the way and the level and gains turned up all the way, I can hear a tiny amount of sound (whatever I'm strumming) come out of the speakers.  Also, it's either clear or metal, so I know that part of the amp is working.  I'd just say the total output of the amp is probably 1% of it's potential?  I've taken the amp apart, searched and scoured for burnt spots on the cirvuit board, bad resistors, loose this or that, I just cant find anything visually and though I am not brand new to electronics, I'd have no idea where to start as far as formal troubleshooting.  :grr   Anyone had this happen? 

P.S.  As a side note, the one thing I noticed is that the tiny amount of sound I can here is not effected one way or the other by the moving of the master volume control...

Thanks.
-Andy