New model Fender Bassbreaker 15 repair

[Clive Robin]

hi, have the same problem with my nearly new Bassbreaker 15. I measured 5 Ohm over one of the 250 Ohm resistors and 200 Ohm over the other. The tube with the duff resistor glows like mad and i measured 235 Degrees C with a digital thermometer. The good tube was around 135 degrees C.
So, is it sufficient to simply remove the Zenner diodes without replacing them and did you have to replace the valves, seeing as one would have been fried?
Thanks in anticipation,
Clive Robin.

[lowell]

Servicing one now... PITA!!!

One of the 39v 5W zener was shorted... tube was redplating. Gonna just remove the zener.

[lowell]

Also like to add that... as is unfortunately very often the case.... this thing is biased to 12.6 watts. Those 240 ohm Rk arent large enough IMO.

[Zentech]

These are modern junk fake tube amps . I cringe at board mounted tube sockets for one . Like disposable Bic lighters .... made to throw out when they stop working . Almost Cost more to fix than to get another one ...... but why make same mistake twice , lol . Very bad bean counter designs .

[goodguy]

Thanks - fixed my red plate on BB15

Removing the 2 Zener Diodes (near power tube area) took me 15 mins and solved my redplating issue on one of the power tubes. Thanks !!!!!!!!!

Now, I just need to solve the NO REVERB issue. Replaced the opamp near the reverb dial but no luck... get no reverb no matter what I do.. checked all connectors etc. what’s next? Ugh...

[popbinge]

Many thanks Unparalleled. Saved me so much time. Thanks for posting this up

[goodguy]

BB15 diodes removed are D12 & D13... no more redplating. Thanks.

on an unrelated note - Reverb doesn't work.... oddly I think I am missing the Reverb DSP board??? How did that happen (amp was bought used)...
There is a missing daughter board that connects at P5 on big board under input jack board. So odd. Wonder if I can source one?
Who would remove a reverb DSP chip board?
Great sounding amp but not sure I would rely on one as a gigging amp seeing as the insides are PCB spaghetti nightmare.

[Jazz P Bass]

"Reverb doesn't work.... oddly I think I am missing the Reverb DSP board??? How did that happen (amp was bought used)...
There is a missing daughter board that connects at P5 on big board under input jack board. So odd. Wonder if I can source one?"

I would call Fender and ask if the DSP board is available.

[TimmyP1955]

BGW had it figured out in the 70s: The component side and the solder side are one and the same. Piece of cake to service (so long as you don't have counterfeit output transistors).

[Alex R]

I just had a guy in with one of these Bassbreaker 15 jobs. Same problem (redplating due to shorted zener), same solution (remove zeners on cathodes altogether). He waited while I did it. Two hours. They are fiddly but board and chassis are reasonable quality and if you take it steady and remove/label most of the soldered-in leads and a few spade connectors it comes out far enough to work on.

[goodguy]

Thanks for the advice... I ended up purchasing a Accutronics BTDR-2 Module (short decay) and jumpered the following pins to BB15 board (L to R looking at BB PCB fro side):
BB Pin #1 (ground) to PIN #2 on Module
BB Pin #2 (+5volt) to Pin #1 on Module
BB Pin #4 (BB Return from Module) to Pin # 6 on Module
BB Pin #6 (BB send to module) to Pin # 3 on Module

Works great!

I have a full write up over at gear page forum if you google “Fender Bassbreaker 15 Redplating Fix & Reverb MOD”

[unparalleled]

How much takes for straight on four full working hours for a 500 bucks amp? Half?

My rate $70NZD/Hr which at the time would equate to about $30USD

[g1]

I just had a guy in with one of these Bassbreaker 15 jobs. Same problem (redplating due to shorted zener), same solution (remove zeners on cathodes altogether). He waited while I did it. Two hours. They are fiddly but board and chassis are reasonable quality and if you take it steady and remove/label most of the soldered-in leads and a few spade connectors it comes out far enough to work on.

I take it there is no way to just clip those zeners out without major disassembly? Could some kind of angled side-cutter get in there?

[printer2]

Found the BB15 service manual here. A few other hard to find ones also. I would like to see the Princeton Recording Amp though.

https://www.manualslib.com/brand/fen...amplifier.html

[Enzo]

Did you contact Fender directly and ask for it?