FDP Home Page / FDP Forum / FAQ's

The FDP is made possible by the following companies and individual members like you.
Please use the links below to show them we value their sponsorship.


Yellowjackets Tube Converters

Apex Tube Matching

Antique Electronics Supply

Jensen Loudspeakers

WD Music


Amplified Parts

* God bless America and our men and women in uniform *

* Illegitimi non carborundum! *

If you benefit and learn from the FDP and enjoy our site, please help support us and become a Contributing Member or make a Donation today! The FDP counts on YOU to help keep the site going with an annual contribution. It's quick and easy with PayPal. Please do it TODAY!

Chris Greene, Host & Founder



Find musicians
in your area!
  Search the Forums  

FDP Forum / Amp Mods, Repairs, and Projects / BJr Preamp Tubes Not Working Intermittently


San Diego, CA

"The night has a thousand eyes."
Nov 15th, 2017 11:28 AM   Edit   Profile  

My ‘03 BJr’s three preamp tubes occasionally won’t power up or have several times shut down while playing. But they will come back on awhile later. Last night at band rehearsal after I powered on my amp, the three tubes wouldn’t light up and of course I got no sound from the amp. I shut it off and checked out the board for loose wires, etc. Saw nothing amiss. I then reattached the back panel and powered on the amp. The tubes came on and the amp sounded fine, normal.

Any thoughts?

Contributing Member

So. Cal. USA

Nov 15th, 2017 01:18 PM   Edit   Profile  

I'd start with these two things. Check all the solder pins for the 6.3 volt heater wiring. I'm not sure it it's in the ribbon cable or is separate green wires, don't remember, but this may be the issue.

Secondly check the solder pads on the tube socket connections to the daughter board.

In both cases a cracked solder joint can be difficult to see. I use magnification and most times just reflow these solder joints when servicing a Hotrod series amp.

(This message was last edited by Hammond101 at 05:10 PM, Nov 15th, 2017)


San Diego, CA

"The night has a thousand eyes."
Nov 17th, 2017 11:21 AM   Edit   Profile  

Thanks for the suggestions H101! I’ll check them out.

Contributing Member

So. Cal. USA

Nov 17th, 2017 11:49 AM   Edit   Profile  

Best of luck!

Contributing Member

Boston Area

Nov 17th, 2017 03:41 PM   Edit   Profile  

As always, great input from Hammond101. Just be sure the amp is unplugged and that any/all electrolytic caps are discharged before you put a soldering iron to pins 1 or 6 on a pre-amp tube.

FDP Forum / Amp Mods, Repairs, and Projects / BJr Preamp Tubes Not Working Intermittently

Reply to this Topic
Display my email address             Lost your password?
Your Message:
Link Address (URL):
Link Title:

Moderators: Chris Greene  Iron Man  reverendrob  

FDP, LLC Privacy Policy: Your real name, username, and email
are held in confidence and not disclosed to any third parties, sold, or
used for anything other than FDP Forum registration unless you specifically authorize disclosure.

Internet Application Development

Copyright © 1999-2019 Fender Discussion Page, LLC   All Rights Reserved