#1
Hi all. Today I had a bit of a SOL situation with my amp today, a Laney GH100L, very nice amp. Anyways, I think I should start with some background info. For awhile I had problems with certain "popping" and crackling sounds coming from the amp, which was worrysome on it's own, so I changed the outlet it was on since I had my other amp (a Jackson Simuvalve 400) plugged in to the same one. For the most part, I had happy days without the strange noises. Recently I started jamming out loud, real loud. The most I ever got to was hardly past 3. Today though, I felt like I should go one step further...to four.

After maybe 10 minutes or so of playing at that volume, everything suddenly cut short. I ran to it and found the standby, power, and even the drive switches were all on their "on" positions, so no ghostly apparition could've turned my amp off manually. What's more distressing was the fact that when I looked through the top grille to see the tubes, they were completely dead, and unglowing; when otherwise they are glowing for awhile when I turn it off safely.

The most devastating part, though, is that now I can't even turn it on. Nothing happens when I flip the switch!

I plan on taking it to the shop as soon as I can figure out some money situations, and this is where I'd like some help: figuring out what exactly happened. If it helps, I play an ESP/LTD V-200 and plug in through a 4x12 cab from the Jackson Simuvalve mentioned earlier. I can answer any questions as well. Thanks!
Last edited by ManOhMan at Mar 8, 2012,
#2
Reading your story it initially sounded like the tubes weren't seated properly but now it doesn't work at all you say? Does anything come on, lights, heaters, etc.
Check the fuses. There should be a HT fuse too, don't know where that is on those. You've probably blown a power valve and it's taken out the fuse.
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
#4
Check the fuses. Sounds like the main one blew. Check them both.
Replace it, make sure all the tubes are plugged in properly and turn it back on. See if another fuse blows. Check them both. Could just be tubes but being the main fuse worries me a bit. If it was the power tubes you'd expect the HT fuse to blow first.
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
Will do man, thanks. What would be worse do you think, the HT or the main one? Could either cause permanent damage to the amp? And could you put a price on replacing them?

Sorry for being such a noob, but this is my first tube amp ever. I do love it though.
#6
Could just be tubes but being the main fuse worries me a bit. If it was the power tubes you'd expect the HT fuse to blow first.
#7
HT usually just means you've blown the tubes.
The main fuse can point to a more serious fault. Impossible to say without looking at it. Could be a loose wire, could be lots of things. It may have just been blown by a surge and there's nothing at all wrong with the amp and simply replacing the fuse is all you need do.

https://ssl.eurotubes.com/cart/index.php?page=view_products&category_id=3&sub_category_id=20

Cheaper and not quite as much headroom:
https://ssl.eurotubes.com/cart/index.php?page=view_products&category_id=3&sub_category_id=19

You'll want to get them biased. Those things are adjustable fixed bias. Something you should learn how to do yourself but most places should do it for you for about $50.
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