#1
Okay guys I have a Blackstar series one 100 watt head. It has a problem and I can't pin point what's causing it. For the most part it works fine... tubes warm up no problem and I have nothing go wrong. But on 4 different occasions I'll turn it on and leave it in stand by to let everything warm up and only the pre-amp tubes will warm up and not the power tubes.

I've had the head for 5 months and I play it pretty regularly at least twice a week maybe more if we have a show that week. I just don't see what would keep the power tubes from warming up. It's been about 2 months since it last happened and it just happened again today.

The first time it happened we left it in a trailer all night and most of the morning... I'm not sure if the high humidity and temperatures here have an effect on it. It seems like every time it happens it's been baking in the heat for a few days. Both of our practice spots reach anywhere from 110-120 in the summer and it seems like anytime it gets really hot over the week it gives me problems. Does the heat and humidity have an effect on them? Our other guitar player has a Peavey valveking and he never has any problems with his and there kept at the same place.

Any input would be greatly appreciated!
#2
Pull out the power tubes. Spray some contact cleaner on the pins and then work the tube in and out of the socket a few times. Make sure they are seated properly and give it a try.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#3
Okay you'll have to excuse me on this question but the tubes just pull straight out correct? I've never really messed with a tube amp before I got this one. And any type of contact cleaner will work?
#4
Yes they pull straight out. There may be a spring retainer you have to move out of the way first but once that's out of the way they pull straight out.
Any type of contact cleaner will do. Deoxit is a good one if you can find it.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#5
Okay thank you! I'll try that first thing in the morning. If that doesn't fix it any other ideas? If one power tube was bad would all 4 of them not warm up?
#6
Do they light up when you turn on the amp? Maybe try it in a darkened room so you can see it more easily.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#7
Nope... None of the power tubes will light up... the pre-amp tubes will light up but not the power tubes. It's done this before but it will work within a few hours... tonight was the exception tho. Never warmed up at all.
#8
I'd actually be a bit concerned that a heater wire has come adrift and is only making an intermittent connection. There's probably a junction that distributes it to the tubes and the wire going to the power tubes has gone open. Take it to somebody before it comes completely adrift and shorts out. You could lose your power tranny.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
Last edited by Cathbard at Jul 30, 2011,