Fender Performer 1000 distortion channel

[showmaster78]

Hi guys,

I have a Performer 1000 and it's developed a couple of issues.
1st, my footswitch doesnt switch channels. No matter whatbthe amp is set to without the footswitch, as soon as i plug it on the amp reverts to clean. As the lights on the footswitch suggest its doing what it should I'm guessing the problem is in the amp.

My 2nd problem is that without the footswitch i can select between clean and od, but i cant select the boost channel.

Are these problems connected or separate issues?
Hoping someone else has experienced this and can tell me either how to fix it or at least where to look...

Thanks guys

[g1]

schematic/service manual here:
http://music-electronics-forum.com/a...ormer-1000.pdf

[showmaster78]

Thanks for the manual, it'll come in handy.
I've noticed C35 and Q5 both seem to be microphonic as well. Could that be related?

[showmaster78]

Thanks for the manual, it'll come in handy.
I've noticed C35 and Q5 both seem to be microphonic as well. Could that be related?

This should nave been C53, not 35

[Jazz P Bass]

How about a little assist.

As none of us here (as far as I know) works at Fender, can you provide the page number & coordinates of where C53 is?

There are test voltages galore on the switching circuit.
I would suggest that you start there.

[showmaster78]

How about a little assist.

As none of us here (as far as I know) works at Fender, can you provide the page number & coordinates of where C53 is?

There are test voltages galore on the switching circuit.
I would suggest that you start there.

Sorry, on the schematic Q5 is ref D3, C53 is ref A5
On the service diagram Q5 is ref B6, C53 is ref C5

Its my first time trying to repair an amp (but Im deadly serious about doing it) so im sort of floundering in the dark a bit lol.
We've all gotta start somewhere, its an awesome amp so I'd love to be able to fix it.

[Jazz P Bass]

Please go through the switching matrix test point voltages.

Post any discrepencies.

[showmaster78]

Please go through the switching matrix test point voltages.

Post any discrepencies.

I'm guessing you mean comparing my findings to whats on the notes in the schematic?
Sorry I'm a bit of a noob but im determined to do this myself lol.
I know how to read a schematic and what all the components are (and how to solder stuff to a PCB etc) but im not well-versed on diagnoses and fault finding.
I'm probably gonna ask some dumb sounding questions and a lot of them because im using my phone so i cant have the schematic open to cross-reference while im on here...

[showmaster78]

Right, spent some time getting to grips with the schematic so i know where my test points are and the expected values. When i get some time this week I'll rip the chassis out and set about it with my multi-meter.
This will be a real learning experience as I'm not really au fait with multi-meters yet so I'll be learning as much about that as i will my amp haha.
Just one question, am i right in saying I connect the black probe to a ground point on the chassis and move the red probe through the test points, checking the results as i go?

[g1]

Correct. Voltages in square boxes are DC, in round ovals are AC.
We are only concerned with DC voltages in the switching area. (TP31,32,33,34,35)
One thing to mention. Any of the dual colour LED's must have both colours working (in amp or in footswitch), otherwise the circuit will not work right. They are green/red, when both are on together it will show yellow. If by chance any were replaced with single red type, it will not work right.

[showmaster78]

Oooooooh, didnt know that about the LEDs screwing up the circuit. I know the reverb LED in the footswitch had a dry joint and had a constantly open circuit but as far as i know all the other LEDs work (or at least they did until i developed the problem). I would actually laugh if, after months of stressing over having to change my setup for gigs, it all came down to a teeny little light lol. I doubt its that simple of course. Like i say I've noticed a few components buzzing horrendously so it'll probably be something like that.

[showmaster78]

Right, test done. Findings as follows:
Just to be clear, I've abbreviated to C, Y and R for Clean, Yellow and Red

TP31: C 494mV, Y 13.10V, R 6.23V
TP32: C 5.8v, Y -16, R -16
So far so good. But then i get this:
TP33. C -5.8v, Y 6.2V, R 6.2V
TP34. C -5.8V, Y 5.8V, R 5v!!!! Red is supposed to be -15v!!
TP35. C 5.8V, Y -16V, R -16V

So i'm guessing U9 is goosed then.
Oh, re: LEDs. Ive got a yellow one and a red one on the front of the amp for my gain selectors
Clean selected, no LED.
Gain 1 selected, yellow LED
Gain 2 should give me the red LED (it used to) but its staying on yellow? Has my red LED bust? How do I test this?

[showmaster78]

Ive just noticed something else (dont know if it will make a difference), when i plug a cable into the footswitch jack on the amp itself (with or without the footswitch on the other end) the yellow gain indicator light up no matter what setting was on the amp/footswitch. Would this point to anything?

[52 Bill]

Ive just noticed something else (dont know if it will make a difference), when i plug a cable into the footswitch jack on the amp itself (with or without the footswitch on the other end) the yellow gain indicator light up no matter what setting was on the amp/footswitch. Would this point to anything?

There is a switch on the foot switch jack that turns on and off the internal panel switches. If you plug something into the jack the circuit will do whatever the foot switch tells it to do.

Start your repair by limiting the problems. Unplug the foot switch and concentrate on fixing the amp first. You state that the amp will switch from clean to dirty but will not switch into red mode. So that tells you that panel switch S3 is working, but S2 may not be. Retest all of the test point voltages using only the panel switches to change settings.

[showmaster78]

Sorry, i should have explained.
Thats exactly what i did as thats what the notes in the schematic said to do.
So i tested everything just using the switches on the amp. The bit about the footswitch was an aside as there is nothing to suggest what to test on the footswitch.

Looking at the schematics and the fact all the voltages at TP31 seem within range (including using all 3 fascia switches) im inclined towards the issue being U8.