#1
Well, I'm in a pickle.
As Cath and some others may remember I recently bought a Crate BV120HW head which needed some repair work done, specificly one of the preamp valve sockets had come away from the board and needed soldering up. I had this done by a local tech and all was good until I put in a new set of preamp valves earlier today. When putting the new valves in I was especially gentle so as not to find myself in this situation again, (the tech having mentioned that on this particular amp the valve sockets were held in place only by the connections themselves) however after putting the new valves in I thoughtlessly began replacing the spring loaded aluminium shelds over the valves and had them all back on before thinking "shit, I bet that's what caused the problem to begin with." Sure enough, when I turned it on the clean channel was sweet (what a difference new valves make) but switching to the OD channel caused it to lose all volume and punch, just as it was when I first aquired it. I actually managed to get it working properly again by taking off the shields and gently pulling up on V2 and V3 (not sure which is the problem) so the socket made contact with the board again and it is working for now but I really need to solder it up properly.
My question to UG's amp savvy members is this: Is this something I could tackle myself? I've got solid soldering skills but only very basic electronics knowledge, although I don't suppose that will be too much of a problem since I don't need to actually diagnose the fault, just fix it. If I do attempt it is there anything in particular I should be careful of?
Thanks in advance for any help you guys can offer

Peace out
#3
After you unplug it from the wall and pull the chassis out the first thing to do is discharge the big filter capacitors. Just short out the two terminals on the caps with a piece of insulated wire. Be very careful, it's around 300V so it hurts. If you use wire you will get a few sparks, nothing to worry about.
Next you have to remove the circuit board. That will probably entail taking all the nuts off the knobs and probably some other stuff as well.
Flip the board over and resolder the tube socket back in place, making sure that there are no cracks in the traces on the board. If there are cracks solder over them. Maybe place a small piece of wire over the break and solder down.
This is why I hate PCB mounted tube sockets.
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
Well, things didn't quite go as planned. I got most of the way through disassembling it when I realised my soldering iron was broke, so that put a stop to things for the moment anyways. I got a good look at the board though and the sockets all looked properly in place and there was no obvious movement when I tried pushing down on them. I put it it all back together and it seems to be working fine now so I'm not sure what's going on. Gremlins perhaps. I have a gig tonight so I'll see how it goes. Luckily I have my faithful, indestructible, transistor powered TBX head to back me up if things go awry.
#7
The sockets themselves are probably crappy. Replace them.
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
#9
The trickiest part is finding ones with the right pins to fit your PCB. If it didn't have shitty PCB mounted sockets you could use anything.
These seem to be pretty good sockets that aren't very expensive. Just compare them to what you have. If they have similar pins then you'll be fine.
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=390291181182
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
#10
They look pretty close actually. I can't afford to do anything right now so I'll just have to persevere with what I have for the moment. I'll get to it down the track though. Thanks for your help anyways mate, I really appriciate it. If you ever find yourself in brisbane let me know and I'll take you out for a few beers.
#11
Well give them a good clean anyway. Bit of contact cleaner on the valve pins and slide 'em in and out a couple of times. It will at least make the best of a bad situation.
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