Hello, newbie here
I've been playing guit-fiddle for more than 3 decades. Got me a Randall RG100 150w head from the 80's (not sure what year). Been a vintage Marshall guy my whole life - love my Marshalls which I'll never sell! But, a couple years ago I got rid of a guitar at a music store and wound up with this RG100 head as part of a trade.
It worked fine for the first 6 months, but it was quite noisy at idle with a loud "waterfall" with "a little hum to it" sound - even on the clean channel and no pedals or anything even plugged into it. Kinda weird. By contrast, my Marshalls are very quiet at idle going through the same Marshall cabinets. I've tried the Randall into other cabs, like Fender, and Ampeg - same result.
Anyways, the clean channel quit working completely. The green light on the front lights up - but no sound, even with volume turned all the way up. Another peculiar thing is that the distorted channel has lost major tone. It no longer has any power and sounds very "tinnny." This gets worse after about 15 minutes of constant playing, until there's barely any sound at all coming out. Both of these symptoms occured at the same time. It has been this way for 2 years - but hasn't gotten any worse.
I'm speculating that the idle noise may be some kind of grounding issue. The power loss may be the capacitors. I really don't know.
I've taken it to several amp repair shops, and the techs at two different shops said that they weren't sure what was wrong with it, and didn't want to take it on. They said the amp wasn't worth it. One of the techs said that it had an RG80 board inside of it. But, another tech said it was normal for Randall to put RG80 boards inside RG100 heads in the 1980's. I've seen the RG80 board inside of it.
The techs took it apart and couldn't visually see anything wrong. They told me that this amp is just junk and not worth fixing, and somebody may have done something weird to it before they traded it in at the music store (like swapping the boards of 2 incompatible amps or something along those lines). Now I'm stuck with it. The guitar I traded in was worth about $200. The value of these RG100 heads are about $200-$250 when nothing's wrong. Mine is now worth $0 since it barely works.
I've considered sending it off to an electronics repair shop rather than going the guitar amp repair shop route. But, that may not work out. I really would hate to just throw it in the garbage or give it to the Goodwill. But, I don't know how to fix it myself either.
I'm very technical minded. I've been an auto mechanic for 15 years, and I have pretty good knowledge of electronics and electrical theory and troubleshooting basic DC circuits. (I know amps are AC) I have a DVOM but no lab scope. But, I'm no amp repair tech - that's for sure!
Does anybody have any ideas? I'd love to fix it for as cheap as possible (or have it fixed as cheaply as possible). I don't have that much money these days, kinda broke with the high gas prices and crap. So, a "quick" and cheap fix is the best for me. I'm not a milliionare!
If I knew what exactly would fix it for sure and the cost is under $100, I'd probably go for it.
Advice and ideas much appreciated.
Thank you in advance,
Kernal Flagg
I've been playing guit-fiddle for more than 3 decades. Got me a Randall RG100 150w head from the 80's (not sure what year). Been a vintage Marshall guy my whole life - love my Marshalls which I'll never sell! But, a couple years ago I got rid of a guitar at a music store and wound up with this RG100 head as part of a trade.
It worked fine for the first 6 months, but it was quite noisy at idle with a loud "waterfall" with "a little hum to it" sound - even on the clean channel and no pedals or anything even plugged into it. Kinda weird. By contrast, my Marshalls are very quiet at idle going through the same Marshall cabinets. I've tried the Randall into other cabs, like Fender, and Ampeg - same result.
Anyways, the clean channel quit working completely. The green light on the front lights up - but no sound, even with volume turned all the way up. Another peculiar thing is that the distorted channel has lost major tone. It no longer has any power and sounds very "tinnny." This gets worse after about 15 minutes of constant playing, until there's barely any sound at all coming out. Both of these symptoms occured at the same time. It has been this way for 2 years - but hasn't gotten any worse.
I'm speculating that the idle noise may be some kind of grounding issue. The power loss may be the capacitors. I really don't know.
I've taken it to several amp repair shops, and the techs at two different shops said that they weren't sure what was wrong with it, and didn't want to take it on. They said the amp wasn't worth it. One of the techs said that it had an RG80 board inside of it. But, another tech said it was normal for Randall to put RG80 boards inside RG100 heads in the 1980's. I've seen the RG80 board inside of it.
The techs took it apart and couldn't visually see anything wrong. They told me that this amp is just junk and not worth fixing, and somebody may have done something weird to it before they traded it in at the music store (like swapping the boards of 2 incompatible amps or something along those lines). Now I'm stuck with it. The guitar I traded in was worth about $200. The value of these RG100 heads are about $200-$250 when nothing's wrong. Mine is now worth $0 since it barely works.
I've considered sending it off to an electronics repair shop rather than going the guitar amp repair shop route. But, that may not work out. I really would hate to just throw it in the garbage or give it to the Goodwill. But, I don't know how to fix it myself either.
I'm very technical minded. I've been an auto mechanic for 15 years, and I have pretty good knowledge of electronics and electrical theory and troubleshooting basic DC circuits. (I know amps are AC) I have a DVOM but no lab scope. But, I'm no amp repair tech - that's for sure!
Does anybody have any ideas? I'd love to fix it for as cheap as possible (or have it fixed as cheaply as possible). I don't have that much money these days, kinda broke with the high gas prices and crap. So, a "quick" and cheap fix is the best for me. I'm not a milliionare!
If I knew what exactly would fix it for sure and the cost is under $100, I'd probably go for it.
Advice and ideas much appreciated.
Thank you in advance,
Kernal Flagg