My CE-2 stopped working

[MTCA]

I'm not sure this is the right place to post this, but i'll try

After a hotel-gig a couple of weeks ago my boss CE-2 (not done anything with it...) stopped working after some real issues with the power in the building. It probably has gotten to little and to MUCH power i guess. The rest of my pedalboard work fine but the old chorus is dead. The LED isn't working, either with PSU or battery.

Does anyone know what has to be done for it to be fine again?  I really like this pedal 


thanks,
MT

[Mark Hammer]

It's very much the right place to post.  DIY means DIY-repair as well as build.

It is possible that everything in the pedal is fine and maybe one cheap component needs replacing.  But we/you need some additional information to assist in this.

So, do you have anything you can measure voltages with to see if the power is reaching things?

[MTCA]

Thanks for fast reply

Yes, I have the right tools, so I could measure some voltages, if I knew where to

[Mark Hammer]

Well, first off, plug in and measure the voltage on the V+ pins of the two dual op-amp chips in there.  That will be pin 8.

If they do not show something in the range of +9v, then check to make sure that ANY power is getting in.  Using battery-power only, check the voltage on each side of D5.

[MTCA]

i'm a real noob, i don't really know where the dual op-amps are, but i measured all of the pins on the three chips and didn't get any power either with a power supply or a battery.

My print board isn't marked either, so I don't know where D5 is 



Only had the iPhone available, and the camera is really just crap, but guess it's better than anything 

-M

[MTCA]

i measured the voltage on both sides on all the diodes, and the only place where I get 8V+ is at this one (on one side)

[kurtlives]

1   8
2   7
3   6
4   5

When you measured the voltages did you have one lead of the meter on a ground reference point.

Dual-op-amps...ICs...Chips....Its all the same crap

[MTCA]

yeah, i did ground one of the leads... but OF COURSE i did forget to put the cord in the input jack (LOL- i'm such a noob)... but i've done it again with the same result, only now I don't get any power from the diode when I have the cord in!!! and it seems like it sucks the power from the battery (quickly!) ...hmmm...

[kurtlives]

yeah, i did ground one of the leads... but OF COURSE i did forget to put the cord in the input jack (LOL- i'm such a noob)... but i've done it again with the same result, only now I don't get any power from the diode when I have the cord in!!! and it seems like it sucks the power from the battery (quickly!) ...hmmm...

If you get a reading and it then starts dropping then something is most likely shorting or discharging to ground that should not.

[MTCA]

I get some readings when the input-jack is NOT plugged in. As soon as I plug in the cord it's dead 

[MTCA]

bump 

anyone?

[MTCA]

 can't anybody help me with this.?  i start to miss it... 

[Andre]

Does the battery get hot when you plug in the input jack.
If so either D7, C29, IC1  or IC2 is defective, since they are the only parts directly connected between 9V and ground.

Most likely the Zenerdiode D7 is defective.
This could happen when you apply reversed power to the DC jack.

You can check this by desoldering one of D7's leads and pull it out of its hole and then start up your CE-2.

[MTCA]

It does get hot after about 30 sec.

I don't know where D7 is, but I'll try to find a schematic and locate it!

Thanks,

[MTCA]

I found the D7 and ejected one of the leads and it worked!!

what sort of zener diode should I use as a replacement?

and how can it work right now, without this diode?

anyway, THANKS ALOT!!

[Andre]

Now that's good news.

D7 is a 11V 0,5W zenerdiode.

It works because D7 is only for reverse polarity protection.
So, also this time it has protected all the more expensive parts.

As you found out it works without, but if you use a DC adapter its safer to get a new one in.

André