What'd you find out on this issue?  I have the same exact amp doing the same exact thing.

Phatt, thank you for your thoughts.  Joe and JM, judging by your responses, it appears as though i have pulled a major boner.  If you look at the first photo (IMG 3853) in reply #20 on page 2, you'll see how I have things plugged in.  When I purchased the setup, the cab was plugged into the "Line Out - Class 2 wiring" jack.  I had used it like that until recently, it was never plugged into the 4 ohm jack, which is located on the opposite side of the amp housing.  How it is in that picture is how I have been running it.  I honestly didn't not know any better to change it.  Have I inadvertently fried something or ruined something?  I really had no idea, dont lose patience with me just yet!  LOL!  I hope that this is not the solution to my entire problem.  Also, if I am supposed to be running off of the 4 ohm jack, have I destroyed the Line Out jack?  I thought that we had discussed bypassing the "phones" and the "4 ohm parrallel" as they are two jacks never used?

I tried jumping the phones connector. I wiggled the cables. I plugged and unplugged connections on the circuit board. I rigged this connector to that ground, on and on and on. I can't get the damn pile of crap to work! So then, I plug my cab into the 4ohm output instead of the "line out" jack. Everything works and sounds normal. What is the 4ohm jack used for normally and can I just use it as my dedicated "line out"? And does this make anything more evident as far as the problem?

So, does this sound like the right path?  If so, which one needs to be grounded, or do they need to be tied into each other and then grounded?  Or am I totally off base...?  :loco

So, my guess would be that the amp is switching grounds here, as I think the black and the blue from the 4 ohm are both grounds and the black and the blue on the "phones" jack look to both be grounds.  Here are some photos, two more of the "phones" jack PCB (top and bottom) and two of the 4 ohm PCB (top and bottom).  If they are just swapping grounds on me, could I just run the correct wire directly to ground on both jacks to bypass the jack switch?  Ugghhh...

Yes, I can do that.  I think there are five seperate PCBs, the tiny one with the phones jack (pictured in an earlier post), the larger one with the 4 ohm paralell jacks, an Identical one on the other side with the speaker outputs and the send/return jacks, a larger one in the center where the two large black round ...apparatuses... are and finally the largest PCB with all of the control knobs.  I'll take a photo of the underside of the 4 ohm PCB and try to label what is what.  Taking photos of the other three would require some intense dissasembly, I'll do it if it will help.  Lemme know, and thanks again!

I apologize for letting this sink into the oblivion for yet another couple weeks.  I have some photos to upload before I started wire nutting, soldering or anything else.  I am not exactly sure what points I need to connect together to bypass the phones jack and the 4 ohm.  The first picture is a close up of the 4 ohm board and the wire connections on it.  There is a ground switch on the left and the two jacks for the 4 ohm parallel.  The second photo is a close up of where the two big wires meet at points labelled SP+1 and SP+2 on either side of a large coil-butron labelled L1.  The third photo is a larger, overall shot of the whole unit, the phones jack belonging in the upper left hand corner and the 4 ohm board in the lower left hand, respectively. 

Well, I am not very confident in my desoldering skills (or soldering, for that matter) on circuit boards.  I got back down and took a few pictures of the headphone jack.  One with it plugged in still, one with it unplugged and one of the underside so a person can get a good idea of how maybe contacts (legs?) it has.  I wonder if Randall (or the guitar manufacturer) builds these with the specific connectors or if this might be a common component available from a retailer with the litte connector and everything ready to go already.  I looked, but to no avail.

Man, I'm having a hard time trying to get any info from Randall.  Online parts seem to be knobs and tubes (apparently, not for my amp).  Do you think parts from this listing on eBay would fit my amp?

http://www.ebay.com/itm/Randall-RH-100-Amplifier-parts-/330681656902?pt=LH_DefaultDomain_0&hash=item4cfe29a646

I am not sure of the diffrence, looks a little older possibly.  Is that a G1, where mine's a G2?  I wouldn't want to get it and find it has slightly different electronics.  Damn, this is just a never ending hassle.  I've probably spent the $200 dollars worth of bandwidth typing on here when I could have just bought a new one!   

So JoeCool, you think the best bet would be to contact Randall about a replacement "Phones" jack?

Man, that is just so hard to fathom, this thing is like brand new.  It must just have been a bad switch from the factory, this probably has less than 4 hours of ON time since unpacking from it's factory box.     K, so are the stereo jacks the ones with the switches that mute to the cab jack or do I need to get all 10 switches (stereo and mono) and if so, which are which?  This process will require me to desolder the old switches off the circuit board and solder new ones onto it, correct?  I haven't done that before.  I saw yesterday in Radio Shack when I bought my floater jack that they had kits for small (scale) projects like that, with desoldering "bulbs" that look kinda like an inline primer bulb on a boat gas tank.  I'm a heavy equipment mechanic, so I think in lamens terms when my electronic experience compares to this stuff.  Too bad Randall didn't have some sort of bulk parts to replace.  A new "Phones" assembly would be nice, just plug it in and bolt it to the faceplate.  Course, it'd probably also be $5,000... 

Whew.  Ok.  I whipped up the vagrant jack and after fiddling and fiddling with it, got it to work.  I was initially getting only loud feedback, then I plugged into my trace elliot to test the pre-amp again and figured I'd give it one more shot and it started working, loud as hell.  So this would be indicative that the switch in either the "phones" jack or the 4 OHM out may be bad?  I have a couple pictures of tonights fiasco I'll try and get up here.  In the overall shot, I labelled the 4 ohm out jack in the lower left of the photo, so you can get a good idea of how the wiring is routed from there to the board and up to the "phones" jack.  There is a close up of the "Phones" jack and it's corresponding, 3 way connection and then there is a close up of the circuit board where I finally found big, fat R27 resistor, wrapped a wire around it and had sound.  Does this mean the heat activated mute safety is not the problem?

Well, I cranked it up and tried to see if I could hear anything when I turned it on and off.  Nothing.  I then plugged the cab cord into the out jack on a Spider III and the cab is making noise like it should, so I guess it's now definitely narrowed down to somewhere in the amplified power?  I'm going to try and post a couple of pictures of what I have.  I don't think they'll be of any technical use but just to give a little better idea of where I'm at.  I have the amp tore down so I can access the circuit board/electronics and I can flip it to get at the heatsink and whatever that suspect looking contraption with the built in thermal fuse is next to it on the top...

Test #1 yielded no results.  Test #2 yielded results.  I plugged my guitar into the input on the Randall and plugged a line from the send jack on the Randall into the guitar input on my other amp and sound was there.  First time I have heard amplified guitar in a long time!  Channels switched back and forth well between clean, distortion, etc.  Test # 3 yielded no results, dead as a doornail.  There were two jacks that I tried on the good amp, one labelled "Line Out" and one labelled "Send", neither of them made any sound on the Randall when plugged into the return jack.

Thank you JM, I will get on this series of tests when I get home.  Thankfully, our main guitar guy has left his amp in the band room so I have a test rig to fiddle with.  I know you've had me plug into the pre-out and the headphone jack to make sure that it's not switching the sound and then that switch sticks, and it didn't make a difference but I'll try these out and let you know.  Thanks a lot for taking the time to help me on this.

-Andy