| Author |
Topic: Question for Ken Fox |
Rick McDuffie
From:
Benson, North Carolina, USA
|
Posted 6 Aug 2006 5:28 pm |
|
Ken, I just bought a '70 silverface Twin from a fellow SGF member, and it's blowing fuses (I knew this when I bought it). It may have the original tubes in it, and is pretty much mint- doesn't look like it's ever been touched. According to my friend, this problem started all of a sudden. Any ideas about what I should check first? Someone suggested taking out the power tubes to see if it still blows fuses... and if it doesn't, to replace the power tubes. Does this make sense?
I have a local tech, or I can take it up to Raleigh to a real Fender guy... but I thought I'd check with you first, in case this is easily solvable. Any help would be appreciated 
Rick |
|
|
|
Rick Johnson
From:
Wheelwright, Ky USA
|
Posted 7 Aug 2006 3:56 am
|
|
RIck
Ken is great amp tech, he can help
you with the amp. I can make a quick
suggestion. Make sure you have the correct fuse in the amp and speaker load hooked
up. Leave all the tubes in it and turn
it on, leave it on standby. Look at all
the power tubes, they should all have
some glow to them. Then release the standby
switch, if the fuse blows, you can bet
a power tube is the problem.
If the amp has not had the electrolytic
caps changed, now is the time for a tune
up with new caps and fresh tubes.
Ken is the man!
Good luck!
Rick
www.rickjohnsoncabs.com |
|
|
|
Rick McDuffie
From:
Benson, North Carolina, USA
|
Posted 7 Aug 2006 4:54 am
|
|
Thanks, Rick. I'll try it before doing anything else.
Rick |
|
|
|
Ken Fox
From:
Nashville GA USA
|
Posted 7 Aug 2006 5:30 am
|
|
Rick is right on.
When I get one like this the first thing I do is:
Pull the power tubes out and turn it on again.
If the fuse holds, you have a bad power tube. Replace them one at time to find the culprit.
If it still blows fuses with the tubes out, then I would suspect a power supply issue or other short circuit. Likely a shorted filter cap.
Remember, that is a Slo-Blo fuse in there, not a Fast-Blo.[This message was edited by Ken Fox on 07 August 2006 at 06:33 AM.] |
|
|
|
Rick McDuffie
From:
Benson, North Carolina, USA
|
Posted 7 Aug 2006 6:47 am
|
|
| Thanks, Ken! |
|
|
|
Ernie Pollock
From:
Mt Savage, Md USA
|
Posted 8 Aug 2006 4:11 am
|
|
For Ken Fox: Ken, first you come highly recommended by Mr Dave Neal in Somerset Pa, I would like to know if an old Pro Fex I have is fixable, its probably the first ones they came out, no card or anything. Can you work on these?? If so, please send you shipping address & I will send it for repair. It comes on, but will not stay on?
We had a power surge one day & its been shot ever since. I have several Boss SE-50's which were not affected at all by that surge.
Ernie Pollock http://www.hereintown.net/~shobud75/stock.htm
------------------
|
|
|
|
Ken Fox
From:
Nashville GA USA
|
Posted 8 Aug 2006 7:17 am
|
|
| Ernie, email sent. I do not work on the Profex One. I try to limit my work to battery-less mods, jacks and pots. I try leave the rest to Peavey. I did fix one that has leaked acid all over the board. The acid flow cut the traces to the data pot in half from the leakage. I had to install jumpers around the traces. |
|
|
|
