HELP! RM100 not working!

[voodoomyk]

Hello, I have been a user on here for a about a year and have posted about this before, but only got limited response.

I have an RM 100 I bought from,a user here, and it hasn't worked since day two of owning it.

When I got it everything worked pretty well. Set up my rig, dialed in tone, and powered down for the night. When I cam back to my rig the next day the tubes weren't lighting up. Was told my heater fuse was out. Had it changed out and the next day it worked for about 10 minutes and popped again. The repair guy said the F3 fuse holder looked like it had been soldered back in. That was the one that was popped the first time.

Any ideas?? Luckily I have another RM100, and a friend's RM 4 rig, but this head has been down for almost a year and I will soon have to return my friend's rm4. So it can't stay out of site, out of mind, anymore.

Tried calling customer service but the number was dead.

 

[Disciple]

Internal fuse more than likely, I had same issue not too long ago and replaced two internal bad fuses and it's back running again.

Not too hard to do on your own and beats paying a tech fee. Just make sure you discharge capacitors so you don't risk shocking and seriously injuring yourself.

Quick discharge tip to take good amount out of capacitors to be able to work safely is power amp on and turn it into play position (make sure there is a speaker load) then you switch off the power switch and leave standby switch in play position, then take out power from wall or disconnect power from back of head. Leave the speaker cable attached and a good amount of the dangerous voltage from capacitors will dissipate through speaker load, do his for a good 5 -10 minutes ( I did 10 ) and then disconnect speaker from amp head. Then you should be good to work inside on fuses, still try to keep hands free from capacitors, the two fuses for tube heaters are not by capacitors anyhow.

 

[voodoomyk]

Hey thanks for the reply. I decided to open it up and take a look. Had another popped heater fuse. Took a look at it, the repairman used a fast acting instead of sloblo. So I will be making a phone call today about my repair bill. Went ahead and changed all the fuses out while I was in there.
Thanks for the tip on the discharge. Way easier than my normal method.

 

[JKD]

I take it you changed the tubes after having these fuses blow twice in a row?

 

[Disciple]

No problem on advice I got that from buddy Rob aka Jaded Faith.

I recommend changing tubes as well when I first changed fuses and plugged back in it blew another, change tubes and fixed

 

[Jaded Faith]

I just wanted to echo the comments about the tubes. If you get the proper fuse in there this time and it goes again it's time to look at why and the first suspect is a faulty power tube.

Let us know how you make out.

Rob

 

[bruce egnater]

EL34 tubes I would guess? Certain EL34 tubes have a much higher than normal turn on surge and can blow those heater fuses. It didn't seem to happen with 5881/6L6 tubes. Those fuses are minimum 10A sloblo If you can find higher than 10A sloblo or high surge rated types, the nuisance fuse blowing will eventually go away.

 

[ibenhad]

EL34 tubes I would guess? Certain EL34 tubes have a much higher than normal turn on surge and can blow those heater fuses. It didn't seem to happen with 5881/6L6 tubes. Those fuses are minimum 10A sloblo If you can find higher than 10A sloblo or high surge rated types, the nuisance fuse blowing will eventually go away.

So if I am running EL34's Bruce says it's OK to use 10A sloblo or higher to fix the problem. Anyone else doing this?