Boss CE-2 Problem. Help !

[Samy]

I have one Boss CE-2 with some problems.
Sometimes works, sometimes don't.  There is always sound, when there is no effect the Depth pot works the Rate pot don't.
I have changed the pot wires but the problem remains, i have checked the pcb traces looking for a cut trace but everything is ok, i have also checked for cold solder joints i seems everything ok too.
I don't understand what the hell is happening, the chorus oscillation disappears and i can't find where. I have checked the MN3007 and MN3101 IC´s just in case but they are ok, i have the original schem but it's not very legible...

Any suggestion to track the problem ?

Thanks

[John Lyons]

Resolder everything around the rate pot and circuitry. If it doesn't fix it then keep resoldering all the connections. If it works and just stops now and then there is a bad connection somewhere. Cold solder joints are sometimes hard to find  visually, especially when you have a lot of tiny pads on a crowded board. Resolder all the connections and clean off the excess flux with a small not too sharp object. A meter probe works well. Excess flux will fool with things sooner or later.
ALso look for small wire strands that may be floating around and sticking out of the off board connections of at the switch and jacks.

John

[Samy]

Thanks Basicaudio.
Before i post here, i heated all the pads and I checked the continuity of the tracks with my DMM.
Today i have done the same thing with the same results. I will not heat that pads again or the tracks will go off.
I decided to use the audio probe and everything is fine until i arrive to the 3101 IC and the TL022, the is no audio signal over there. Like i said before, i have audio signal on the pedal and is not identical like it was in bypass, the depth works but there is no oscillation and the Rate pot doesn't work.
I believe that i must have audio at least at the TL022, i don't know how the 3101 works but i think it must have audio too ...
Is there a better original schematic, mine is not very legible ? I have the CE-3 service manual, if someone can give me the location to find the CE-2 s.m. it would be excellent.

[Fuzz]

No audio in TL022 and MN3101 "areas", they're just oscillator and BBd driver; the former, maybe, a BAD oscillator. Try to change it, I think is simple to find a TL022 in a local store (use a socket). Another thing to double check is the voltage divider: find it and check it with your DMM to find a good half-voltage. I often find bad filter caps in vintage effects.

Fabio

[Samy]

Fortunately, i have one TL022 but i don´t have one 3101. The problem is that sometimes works sometimes don´t , and it´s had to believe that one bad IC can cause it ! A bad cap can be the problem if it has somekind of leakage. I will try to understand better the schematic and how the pedal works to find the problem.

[Samy]

I found the problem.
After checking the schematic, it was obvious that the problem was around the TL022 because the Rate and Depth pot are connected over there, my last option was the IC3101.
After soldering the TL022 i saw that 3 IC pins were broken, after placing a IC socket and a new TL022, the pedal works fine.
I was impossible to see those broken pins, it was really a pain in the back side tracking this problem ! I prefer a completely burned components that  problems like this.

Thanks to you all.

[Fuzz]

Excellent! 

[jonathan perez]

why didnt you use sockets?

[Samy]

The Ce-2 is the original one, there are no sockets in the original pedals but i have placed the sockets now.

[Samy]

Just one correction.
When i wrote "after soldering the TL022" i mean "de-soldering" .

Sorry my English.