Hi guys!

Just thought I'd update you and maybe help people who may have this issue in the future, I fixed it!

I spoke to a friend at work about it and he recommended cutting away a section of the  ground plane above R41 (the resistor that was arcing). So I tried it and the amp now works beautifully! No more arcing!

Cheers for all the help!

Hey guys,

I've been so busy lately I haven't had a chance to get the amp out again. Thanks so so much for your replies, I appreciate them very much!

I promise I haven't hit and run this thread, I'll be back with an update soon!

Cheers,
StiffCookie

Oh and by the way, I've discovered there are different versions  of the RG100. This one is a "Valve-Dynamic RG100 G3 (100W Tube/Mosfet Power)".

Plus I also checked the voltages of the PSU (Main board disconnected). I'm getting:

QC1 - 58.70V DC. (QC13 on PSU)
QC5 - 382.0V DC. (QC14 on PSU)
QC6/QC7 - 13.5V AC (The two orange wires directly form the transformer [HTR]).

Full PCB:

Hey again,

I've taken a few pictures of the board.

The first one is a picture of the the overheating resistor (R24). The resistor above is the one that is arcing to the track above it (R41, left side leg). The right side of R41 actually has a solder bridge on the other leg, I don't know if this is by design or if it's a previous owners mod.

The second picture is the PCB number and revision  (maybe helpful).

The 3rd and 4th pictures are of the only zeners that I could find.

The 5th picture is of a 1M resistor mod, again I don't now if this is a factory mod or a user mod, any ideas? I wondered if these were user mods (not sure how I would find out), is it worth undoing them?

Thanks again.

Hey Phatt,

Thanks so much for taking the time to check out the schematic and making these suggestions, I appreciate it very much!

I have some free time this weekend so I'll have a look at the those components and take some pics of the PCB.

Cheers!

Hey guys,

I recently acquired a Randall RG100. It kind of wants to work, but sounds like it keeps rebooting (so to speak). Rather than trying to explain the symptoms in detail, I've attached a YouTube video below instead. There is a little more information in the description section on YouTube.

https://www.youtube.com/watch?v=rxfLPj4yJZw&feature=youtu.be

Any ideas?

Thanks guys!
StiffCookie