Help. Tonepad CE2 debugging

[syamilaliff]

Hi,

I got a problem with my build.

It seems that the MN3007 and MN3101 is not getting the correct voltages.
I run countless of times checking for bridges but cant seem to find one.

Here are the voltages :-

MN3101
1. 9.2
2. 9
3. 0.02
4. 9.1
5. 9.2
6. 9.2
7. 0.68
8. 9.2

MN3007
1. 9.2
2. 9.2
3. 5.3
4. 9.2
5. 0
6. 9.1
7. 9.2
8. 9.2

IC1
1. 4.5
2. 4.5
3. 4.5
4. 0
5. 4.5
6. 4.5
7. 4.5
8. 9.2

IC2
1. Varies
2. 4.58
3. Varies
4. 0
5. 4.58
6. 4.57
7. Varies
8. 9.2

Seems that my signal is lost at C10. I got sound at R13. I've spent one whole day troubleshooting this circuit and still cant find any bridge.

Any help is appreciated on where I should look further.

Thank you.

[Slowpoke101]

The voltages on IC1 and IC2 look good but IC3 and IC4 are very wrong.
The clocking chip (IC4) is not working. The following voltages are from a working CE-2 clone with both Depth and Rate controls set to mid-range;

IC3 - MN3007

1= 9.1V
2= 4.7V
3= 5.1V
4= 0.65V
5= 0V
6= 4.66V
7= 5.08V
8= 5.08V

IC4 - MN3101

1= 9.1V
2= 4.66V
3= 0V
4= 4.7V
5= 0.4V (varies slightly)
6= 7.9V (varies slightly)
7= 1.7V to 3.2V (varies relative to Rate and Depth)
8= 0.616V

There have been quite a few fake MN3007 chips sold and they do not work at all. Remove IC3 and re-measure the voltages on IC4 and see if they are now close to the voltages above.
Be prepared to source another MN3007 and probably a MN3101.

[syamilaliff]

The voltages on IC1 and IC2 look good but IC3 and IC4 are very wrong.
The clocking chip (IC4) is not working. The following voltages are from a working CE-2 clone with both Depth and Rate controls set to mid-range;

IC3 - MN3007

1= 9.1V
2= 4.7V
3= 5.1V
4= 0.65V
5= 0V
6= 4.66V
7= 5.08V
8= 5.08V

IC4 - MN3101

1= 9.1V
2= 4.66V
3= 0V
4= 4.7V
5= 0.4V (varies slightly)
6= 7.9V (varies slightly)
7= 1.7V to 3.2V (varies relative to Rate and Depth)
8= 0.616V

There have been quite a few fake MN3007 chips sold and they do not work at all. Remove IC3 and re-measure the voltages on IC4 and see if they are now close to the voltages above.
Be prepared to source another MN3007 and probably a MN3101.

It was the BBD. Tried a few of them and only a pair of them works.

Thanks for your help.