Boss CEB-3 switching problems

[JuanB]

I have a Boss bass chorus CEB-3 pedal that does not reliably turn on or off, especially when it has been unpowered for some time. This issue becomes less likely if it has been powered for a while. When I depress the switch, the LED will light up but it may go out as soon as I release the switch. Sometimes the LED will flash on/off quickly as I depress the switch. I replaced the switch and this did not fix the issue. I’m wondering if it’s a flip flop circuit cap issue given the nature of the problem. Does anyone have any insight into this issue? I believe this is the analog version of the pedal as I bought it about twenty years ago.

[g1]

Does this schematic match what you have?

[JuanB]

Does this schematic match what you have?

Thanks for the reply. I think that’s the newer digital version. I haven’t been able to find the schematic that matches my pedal. I’ll post some pics of the innards later.

[g1]

Still, it's a very typical Boss switching arrangement.
Attached is schem. for an old CE-3, which uses a similar switching circuit. Chances are that your unit uses the same arrangement as the others.

[JuanB]

Yes, the switching circuit looks the same. Just wondering how to troubleshoot it to see if it’s a capacitor or transistor issue. Or maybe it’s not related to the switching components, though I doubt that. Thanks.

[Mick Bailey]

Make sure the ground side of the switch has continuity to the pedal case. If it grounds via one of the sockets make sure the nut is tight enough. I've never seen a cap in this switching circuit fail, though it wouldn't be impossible - they're ceramic operating under low voltage and very reliable.

[JuanB]

Make sure the ground side of the switch has continuity to the pedal case. If it grounds via one of the sockets make sure the nut is tight enough. I've never seen a cap in this switching circuit fail, though it wouldn't be impossible - they're ceramic operating under low voltage and very reliable.

Thanks, Mick. I’ll give that a try. The fact that the problem diminishes if the unit has been on for a while seems to point to an issue unrelated to grounding, though. I did notice that the input jack nut is somehow cross threaded which is strange. I’ve never disassembled the jacks and now I can’t disassemble the input jack easily. Either it came that way or maybe the plug in the input was stepped on forcing the nut to cross thread? No idea how that would happen. So it is a bit loose on the casing. I’ve tried manipulating that jack during tests with no effect on the problem.

[JuanB]

For posterity: Turns out it was likely the input jack even though I thought I was properly grounding it during testing. As I explained in one of my posts above, the input jack nut somehow got cross threaded and all the input jack was slightly loose on the pedal housing. Even though I held it tightly against the housing during testing, the switching was still behaving strangely as described in the OP. After replacing the input jack, the pedal switches reliably. Thanks to all who offered advice.