tonepade Boss CE-2 not working

[astrodave]

Hi all
This is my first..... I have just finished this pedal (chorus) the problem is when you turn it on all i get is a really clean guitar sound with no chours effect what so ever. I have checked all solder points and they are fine. I have adjusted the trim pot really slowly and this doesn't change the sound at all. if you disconnect the power there is no guitar sound. the true bypass works, any suggestions, or do you think its faulty MN3007 OR MN3101.

Thanks

Dave

[PRR]

Welcome.

"Doesn't work" is hardly a clue. Some investigation is needed. Start here:
http://www.diystompboxes.com/wiki/index.php?title=Debugging

> all solder points and they are fine.

Nevertheless, flawed solder is the #1 most popular problem.

> I have adjusted the trim pot really slowly and this doesn't

Good step. I'd also wonder if that voltage were really changing.... in fact if any voltages were right/wrong, which is why we rudely direct you to the Debugging page above.

> faulty MN3007 OR MN3101.

Where did you get them? There's good and bad all over.

[astrodave]

Thanks for the quick reply PRR. I have gone through the debugging page again and everything seem to be ok. I have also checked the transistors and they are all working. All the ic's have power and are grounded. Trim pot is working, i'm not sure what voltage i should be getting at the trim pot. The MN3007 and MN3101 ic's were bought from ebay from Hong Kong.. Thanks again for taking the time to answer my post.

Dave

[astrodave]

I have replaced the MN3007 and Mn3101, still no effect. has anyone got any voltage values for the ic's and transistors for a working ce-2 or any other info. I have just bought an oscilloscope so any info on checks i could do with it. Thanks Dave

[induction]

Thanks for the quick reply PRR. I have gone through the debugging page again and everything seem to be ok. I have also checked the transistors and they are all working. All the ic's have power and are grounded. Trim pot is working, i'm not sure what voltage i should be getting at the trim pot. The MN3007 and MN3101 ic's were bought from ebay from Hong Kong.. Thanks again for taking the time to answer my post.

Dave

It's good that you went through debugging steps, but for us to help, you have to post the results (voltages and photos are a good starting point) so that we can look for red flags. Here's another link with more specific instructions about what to post so that we can help.

[nickbungus]

I've just built one this week (still not boxed) so post your voltages and I'll check and post mine.

[astrodave]

Thanks everyone for your help readings are as follows...
Power =9.27v
voltage set on IC1 pin one with trim pot
IC1
1=5.39
2=4.47
3=4.46
4=0
5=4.47
6=4.47
7=3.56
8=9.27

IC2
1-8.65
2=4.98
3=8.89
4=0
5=5.00
6=7.78
7=9.12
8=9.27

IC3 MN3007
1=7.97
2=5.93
3=0.99
4=1.00
5=0
6=4.03
7=7.52
8=7.52

IC4 MN3101
1=7.98
2=4.05
3=0
4=5.92
5=0.32
6=7.10
7=2.47
8=1.05

Q1
E=4.98
B=5.29
C=9.27

Q2
E=5.06
B=5.61
C=9.27

Q3
E=0.19
B=0.18
C=8.99

Q4
E=2.12
B=2.65
C=8.00

Q5
E=0
B=0.4
C=6.72

Thanks for the help :-)

[anchovie]

The MN3007 and MN3101 ic's were bought from ebay from Hong Kong.

That's where I got mine from when I built the same board about 5 years ago, and initially it didn't work. I read on a forum (might have been this one) that there was a big batch of dodgy grey-market 3101s out in the field, and the solution was to leave pin 8 floating. I think I had to use a new chip as the first one got fried ('twas a long time ago!), but I did use sockets so I just bent pin 8 to be pointing up in the air. The chorus fired up and still works to this day.

[astrodave]

Hi, some pictures of my Tonepad CE-2 Build, I have since re-soldered all the dodgy solder joints...

https://www.flickr.com/photos/103268481@N02/21092207953/in/dateposted-public/
https://www.flickr.com/photos/103268481@N02/21525340058/in/dateposted-public/
https://www.flickr.com/photos/103268481@N02/21526307359/in/dateposted-public/

Thanks
Dave

[nickbungus]

Here we go:  There are a few discrepancies, especially IC3 and Q3.

DC=9.28

IC1
1=5.39  Was 6.53 ( I had a really nice sound too at that voltage)
2=5.41
3=5.39
4=0.03
5=5.39
6=5.40
7=5.41
8=9.29

IC2
1-5.5 Max (Fluctuating)
2=4.6
3=6.76 Max
4=0.03
5=4.7
6=4.7
7=5.6 Max
8=9.29

IC3 MN3007
1=7.62
2=4.76
3=4.68
4=.62
5=0
6=4.7
7=4.65
8=4.6

IC4 MN3101
1=7.61
2=4.68
3=0
4=4.76
5=0.32
6=8.1
7=3.2 max
8=.6

Q1
E=4.40
B=4.73
C=9.30

Q2
E=4.68
B=5.2
C=9.30

Q3
E=4.46
B=4.86
C=9.28

Q4
E=2.12
B=5.17 Max
C=5.41 Max

Q5
E=0
B=0.435 max
C=7.6

[astrodave]

Thanks for the info nickbungus
I will have another look at the same voltage and see If I can see anything.....

[bloxstompboxes]

It may have been the small clone but I think it was perrow and DA that were having a similar issue and it was that a sub had been made on the transistors. They had used 2n3904s instead of 2n5088s I think. Any subs like that going on here?

[Fender3D]

As I said in the other thread, bias voltage is way too low for MN3007.
Check if it changes when you turn the trimmer @ MN's pin 3.

Hint bias passes through Q2 before reaching IC3...

[astrodave]

Hi

Ive changed the MN3007 chip, and pin 3 now has 3.02v it dose change with the trim pot. but the chip is getting really hot any ideas?

[nickbungus]

Dave, check your pots.  I put mine in an enclosure last night.  I had a 100k log as one of the pots (Rate I think) because that's what I had, but I bought some 100k linear ones in to do the enclosure.

When I put the new pot in I had a clean sound with no effect.  If I manhandled the pot (not adjusting it), it came to life.  If I grounded it, it came to life.  I whacked it in the enclosure (as it would be grounded) and all seems fine.  The soldering on the pot seems fine and the joints on the PCB seem clean.  Seems odd but its working.  If I have any issues going forward I'll resolder the board connections of the pots.

[astrodave]

Hi
I've checked my pots all seem ok the are in an enclosure anyway. I am more concerned with why the mn3007 is getting so hot....thanks for the reply