Vibrato not working in Showman Reverb TFL5000D

[dupedd]

The reverb works fine and I've tried replacing the v5 tube(the only thing I know to try) but there's no tremolo. I plugged up my rev/vibr Fender pedal and the reverb can be turned off and on but no vibrato. Any ideas of what I could try? Thanks!~edd

[alltone]

http://i303.photobucket.com/albums/nn150/douglasamps/Picture1-1.jpg
Check the vibrato RCA jack for good contact..and solder points on the .01 and .02 caps.Check voltages re: diagram..If still no go ..It may be the photoresistor..but these parts seldom fail.Best guess would be a bad solder point.

[Blue Strat]

Try switching the reverb and tremolo pedal jacks in an effort to make sure that both footswitches are working.

[WaltC]

And if you open up the amp to check out the solder joints and caps, while you're in there look at the back end (the one closest to the back of the chassis) of the trem roach (the bug looking thing pretty much in the center of the layout picture that DouglasAmps posted) and see if the light it flashing when the vibrato should be on. One way to be sure that the vibrato "should be on" is to plug in a RCA jack (or single audio cable) to the Vibrato footswitch jack and short the center pin (hot) to the outer shield. That will turn the vibrato "on" and then look at the back of the roach and see if the light flashes. Let us know what you find out...

Or you could take it to your local tech .... <G>

[dupedd]

I just got done looking under the hood and checked all suspect solder joints and they seemed solid. I did poke around a bit, wiggling and such somewhat. The vibrato RCA jack was a nice joint but the female pin the wire was connected too is slightly looser than the other RCA jack's pins. I turned it on and noticed the "bug" was lighting up when the vibrato was on and now it worked! Bothe the vib. and reverb work. I don't know what could have happened to fix it...?! The vibrato still sounds a little weak to me but it's still way better than nothing. ***BTW, there is NO resister between the vibrato and reverb jacks on my amp as shown in the schematic.*** There is one between the 'reverb pedal' jack and the 'reverb output' jack. Go figure.

Below is my experience with experimenting with hooking the pedal up differently before I got inside the amp. I'm still confused about what could have been happening(I wrote this before getting inside the amp):

-I just tried switching the pedal jacks and now the vibrato works but pretty faintly, even with the intensity up all the way. When the other switch is engaged the reverb comes in faintly(when on 10) and there is a drop in volume and a high pitched monotonous squeal accompanying it.
I did notice that when plugged up the original way there is a slight vibrato going when engaged but faint(like intensity 1-2 when it's on 10). Reverb engaged works fine in this setup.
I tried unplugging the pedal altogether and the reverb's intensity is significantly less on 10 than when it is plugged in. Also the volume greatly increases as the reverb is turned up with the pedal unplugged. Vibrato doesn't work at all in this setup.

[Blue Strat]

To increase trem intensity install a Surf Bug (use Google to find one). These are great and also make the trem channel sound better when the trem is turned off.

[alltone]

To increase trem intensity install a Surf Bug (use Google to find one). These are great and also make the trem channel sound better when the trem is turned off.
Also..you could try replacing the .01 and .02 ceramic caps. with these.http://www.radiodaze.com/C-OD15.JPGFresh caps may restore the photoresistor's(the bug's) intensity and ..clean, tight contacts on the RCA female( input) and on the jack plug(footswitch)

[mark norwine]

never overlook the cathode bypass cap. If it's shot, the unit won't work.

(not the case here, but a good thought to keep in mind)

[dupedd]

Thanks for the help guys, it's much appreciated.

[mbratch]

***BTW, there is NO resister between the vibrato and reverb jacks on my amp as shown in the schematic.*** There is one between the 'reverb pedal' jack and the 'reverb output' jack. Go figure.The schematic shows the resistor/cap network going to a ground, not the vibrato jack. It can be connected to a ground anywhere they found suitable to grab it.