DC-5 footswitch help

[Chris K]

So, I lent my DC-5 combo out to a friend for a two week period. Got it back and my friend says the channel select button on the footswitch stopped working. He says he didnt really do anything but step on it a few times. He is not in a band and he practices in his parents' basement so I believe he probably didn't do anything malicious.

Anyway...I opened up the cable end and the enclosure box and all solder connections appear to be fine. The EQ select works alright, just the channel select doesn't work.

I was wondering if anyone knows how to test the switch and/or cable with a multi-meter to help narrow down the culprit. I am thinking the mexican made switch is shot but want to be sure before taking it apart.

Any help would be appreciated. Thanks
Chris K

 

[MJ Slaughter]

With a tip ring sleeve, stereo plug, in the footswitch jack and it's cover unscrewed I believe that you can jumper a wire from the shield to the tip which will trigger the channel change function on the amp. Jumping the shield to the ring should turn the EQ on and off. That way you should be able to rule out a problem inside the amp if it works. If it doesn't work then you might have a bad LDR. Always best to rule out a switch/cable first.

 

[Chris K]

Thanks for the reply. I will try the jumper trick when I get home tonite.

In case it is the switch, any advice on a replacement source? Mouser? Parts Express?

Also...can you elaborate on "bad LDR" if it is the amp. Is this user serviceable or do I need a qualified tech to replace?

Guess its a good time to find a schematic for the DC-5 since I plan on having if for...oh I dunno....ever.

 

[MJ Slaughter]

I would be surprised if it were the switch but if it is it may be just as easy, as with most parts, to order it from Mesa Boogie. As for the LDR's, I'm not qualified to speak about those much. There are others on this board very knowledgeable who can help or you can search past posts about the subject. My understanding is that they control the switching that goes on and even for me they are easy to replace if you are experienced with a soldering iron and careful. Before doing anything inside you should discharge the large caps so they don't kill you. That always sucks. One member here Monsta-Tone has spoke about LDRs a lot and if I remember correctly he will replace them on an old amp even if they are not giving him any trouble just so theres one less thing to worry about.

If you want to give me your email I'll send you the schematic.

 

[MusicManJP6]

Seems like LDR issues are fairly common with the DC series. Mine works just fine still - thankfully.

 

[Chris K]

I was thinking it was the switch since the channel select LED on the footswitch doesn't light up, but the EQ switch and EQ LED work fine. If I use the toggle switch I can change from Rhythm to Lead as expected.

As for these LDR's I have searched and found some topics, but nothing specific to the DC-5. I also found a schematic and it seems there are more than one LDR.

If it is not the switch I may be over my head and may have to take it to a local tech.

 

[brungio]

This happens to me a few times and I have to make sure the switch on the front is set to the middle which allows the footswitch to change the channel.

I also get this same behavior when the input jack isn't fully making contact with the input.

Sounds dumb but I often forget to check these simple things

 

[Monsta-Tone]

This happens to me a few times and I have to make sure the switch on the front is set to the middle which allows the footswitch to change the channel.

:lol: I've done that a few times too!

 

[Chris K]

The first thing I checked ws the toggle. Its in the center position and the footswitch doesnt change from lead to clean, but the EQ which I use as a boost still works on both channels.

I tried the jumper cable trick but only got some strange fast repetative clicking noise on the EQ side, and nothing on the channel select side.

Luckily I primarily use it only on the rhythm channel with pull boost, and only occassional use the lead channel and i guess i can still use the toggle when i need to.

Guess its time to take it to a tech. Also time to dust off the blues deville and v-twin pedal.

 

[boogietone]

I went through something similiar on my DC-5. My problem was switching the
the GEQ on and off. To rule out the footswitch, I took it apart and swapped
the wires around making the GEQ switch the channel switcher and the channel
switch the GEQ switcher. The footswitch is a very simple circuit. So, my original
problem was the GEQ switch on the footswitch didn't work. After rewiring the
footswitch now the channel switching didn't work but the GEQ switch now worked.
So that told me it was something inside the amp. The LDR I'm sure. I still need to
send it out to get it fixed. I can do some soldering but this one I'm not so sure about
trying to do myself.
Good luck with your problem!

 

[bigjav]

Boogietone, from what you decribe here, I would say the problem is your switch... for sure. Because with the "new" foostwitch, i.e. with the channel switch the GEQ LDR responds correct. Conclusion: the problem is the footswitch itself.

Or may be I got it wrong?!?!?

 

[lockbody]

I went through something similiar on my DC-5. My problem was switching the
the GEQ on and off. To rule out the footswitch, I took it apart and swapped
the wires around making the GEQ switch the channel switcher and the channel
switch the GEQ switcher. The footswitch is a very simple circuit. So, my original
problem was the GEQ switch on the footswitch didn't work. After rewiring the
footswitch now the channel switching didn't work but the GEQ switch now worked.
So that told me it was something inside the amp. The LDR I'm sure. I still need to
send it out to get it fixed. I can do some soldering but this one I'm not so sure about
trying to do myself.
Good luck with your problem!

I don't understand your reasoning, as it seems like the problem followed a bad footswitch toggle. If something was bad in the amp and the footswitch was good, swapping the wiring between the two footswitch toggles wouldn't make a difference.

 

[boogietone]

I apologize for the confusion. It was late and I was tired. Let me try again.

Before rewiring the footswitch:
The GEQ footswitch did not switch the GEQ.
The channel footswitch did work on changing channels.

Swapped wires in the footswitch making the GEQ switch operate switching
channels and the channel switch now operates the GEQ.

After rewiring the footswitch:
The GEQ switch switches channels.
The channel switcher does not switch the GEQ.

Put wires back to original position:
Again, GEQ footswitch does not switch the GEQ (but successfully switched channels when I had swapped wires)
Channel footswitch does change channels (but did not switch the GEQ when I had the wires swapped)

So, both switches in the footswitch work because they both were able to change channels as proven by rewiring
the footswitch.
But neither footswitch was able to operate the GEQ.
Unless I missed something, that would indicate something inside the amp, right?
Again, my apologies. I'll not try typing that late again.