Results 1 to 6 of 6

Thread: Fender 94 Twin Amp with strange broken pot

  1. #1
    Supporting Member Randall's Avatar
    Join Date
    Jan 2013
    Location
    Cape Coral, FL
    Posts
    1,784
    Thumbs Up/Down
    Received: 115/0
    Given: 16/0

    Fender 94 Twin Amp with strange broken pot

    This is the black knob verision, came in with the shaft pulled out of the Ch 2 volume pot. The push/pull is channel switching. First off, I had a bear of a time getting about half of the knob set screws to turn. They were so tight, some of them released with a crack using the biggest screwdriver I could fit. Then, about half of the pot nuts were on so tight I could not release them with my Excelite nut driver, I had to use a 9/16" socket and wrench. WTF.

    When I got the board out I saw the pot body and switch box pushed back away from the chassis enough that everything seperated and fell apart as soon as I unsoldered them from the board. Tabs were bent, and parts were distorted like it took and awful hit. Yet, this does not reconcile with being bolted to the chassis and a big skirted Fender knob that would not allow this kind of inward pressure.

    So I am left wondering, how did this occur?

    0 Not allowed! Not allowed!
    It's weird, because it WAS working fine.....

  2. #2
    Senior Member nevetslab's Avatar
    Join Date
    Apr 2010
    Location
    Burbank, CA
    Posts
    1,059
    Thumbs Up/Down
    Received: 236/1
    Given: 566/1
    Man, you sure took in a puzzler there! Very few times have I been unable to back out the set screw on the 'standard Fender Skirted knobs as used on the 94 Twin Amp. I gather no signs of moisture or rust on the set screws. Rust & time will yield them to be a PITA, but nothing like what you found here.

    I agree with your assessment....how the dickens could a front hit on a knob drive the shaft back thru the bushing to take out the pot, since the knob would bottom out against the chassis front panel. All those pots use an 11mm hex nut. 9/16" nut? yes...WTF? I've had to replace that push-pull volume pot more than once, but never encountered what you've found this time. I've certainly had set screws strip out, but locked into place? Only thing I can think of there was someone must have thought using loctite on the set screw was the thing to do.

    1 Not allowed! Not allowed!
    Logic is an organized way of going wrong with confidence

  3. #3
    Old Timer Leo_Gnardo's Avatar
    Join Date
    Sep 2012
    Location
    Dogpatch-on-Hudson
    Posts
    5,586
    Thumbs Up/Down
    Received: 665/15
    Given: 718/0
    Agree with nevets ^^^ (as usual) AND if there were 9/16 nuts on all the pots, not the usual half inch or 7/16, I have to think someone replaced them all with non standard hardware, and may have gotten happy with the Loc-tite or krazy glue Perhaps the pot damage happened before the pot nuts & knobs were skunked up, and the last "tech" inside decided to retreat without fixing the pot. Hope you can get this amp sorted without any further problems!

    0 Not allowed! Not allowed!
    Enjoy. Every. Sandwich.

  4. #4
    Supporting Member Randall's Avatar
    Join Date
    Jan 2013
    Location
    Cape Coral, FL
    Posts
    1,784
    Thumbs Up/Down
    Received: 115/0
    Given: 16/0
    My bad, it was 7/16" not 9/16".

    0 Not allowed! Not allowed!
    It's weird, because it WAS working fine.....

  5. #5
    Senior Member nevetslab's Avatar
    Join Date
    Apr 2010
    Location
    Burbank, CA
    Posts
    1,059
    Thumbs Up/Down
    Received: 236/1
    Given: 566/1
    I think it was back in the days of being a bicycle mechanic, where I discovered 11mm & 7/16" wrenches and sockets worked on the same nut. Same with 14mm & 9/16". And a 13mm 12-pt socket will drive the 1/2" square bolt in Greenlee Chassis punches. Nice to have the leverage and ratching handle driving chassis punches.

    Not that any of this has to do with Randall's puzzle on how the heck did this Twin Amp get so afflicted with abuse.

    1 Not allowed! Not allowed!
    Logic is an organized way of going wrong with confidence

  6. #6
    Old Timer
    Join Date
    May 2006
    Location
    Chill-Ville, VA
    Posts
    2,719
    Thumbs Up/Down
    Received: 264/4
    Given: 559/11
    Also 16mm & 5/8", I believe... & 19mm & 3/4". But that doesn't really apply to amps. That's just on Fords.

    Jusrin

    1 Not allowed! Not allowed!
    "... If an older Boogie and classic Marshall had a (clearly illegitimate) child and you baked it in an oven set to clown shit crazy." - Chuck H. -
    "When receiving a shock I emit a strange loud high pitched girlish squeak." - Alex R -
    "All I ever managed to do with that amp was... kill small rodents within a 50 yard radius of my practice building." - Tone Meister -

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Fender red knob twin vs Fender twin reverb 65 reissue clean channel with Les Paul
    By jalexquijano in forum Maintenance, Troubleshooting & Repair
    Replies: 3
    Last Post: 11-20-2017, 03:34 AM
  2. Fender Hot Rod Deville Channels Broken
    By Jtwusmc in forum Guitar Amps
    Replies: 2
    Last Post: 03-04-2013, 10:39 PM
  3. Fender Twin amp strange oscillation/ motorboating.
    By jpfamps in forum Maintenance, Troubleshooting & Repair
    Replies: 11
    Last Post: 11-16-2011, 08:43 PM
  4. strange noise in my 66 blackface fender twin not re issue
    By chris61 in forum Maintenance, Troubleshooting & Repair
    Replies: 13
    Last Post: 01-01-2011, 08:01 PM
  5. Fender BXR300C w/broken trace...?
    By acorkos in forum Maintenance, Troubleshooting & Repair
    Replies: 1
    Last Post: 05-06-2010, 01:27 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •