CE-2 Debug

[Zben3129]

I have sound, but it isn't affected by the whole BBD/LFO parts of the circuit, as these can be disconnected with no change to the sound. Problem must be down there somewhere

I was looking around for a voltage table for the CE-2 but couldn't find one. Does anyone have voltages I could use as a reference?

Thanks

Zach

[natalio]

I had the same problem, so look at this:
Andre posted his voltage levels for reference, and it was really helpfull


http://www.diystompboxes.com/smfforum/index.php?topic=69046.0

Hope this help!

[gigimarga]

Try to adjust the trimpot...i had the same problem 

[Zben3129]

Alright, I have some voltages, and it seems that there aren't one or two that are off. There are TONS that are off. I'm starting to suspect a bad 3101, I bought it from one of those hong kong ebay sellers.

The "top part" of the circuit is working fine (4558 and its input buffer) so I won't post those voltages (they are correct)

MN3007:
1: 7.3
2: 1.2
3: 4.8
4: 3.4
5: 0.0
6: 0.8
7: 7.2
8: 7.2

MN3101:
1: 7.3
2: 0.8
3: 0.0
4: 1.2
5: 1.3
6: 6.1
7: 0.8
8: 3.4

TL022:
1: Varies
2: 4.5
3: Varies
4: 0
5: 4.5
6: 2.4
7: Varies
8: 8.7

Q2:
E: 5.8
B: 5.7
C: 8.7

Q3:
E: 5.5
B: 4.4
C: 8.7

Q4:
E: 3.5
B: 3.3
C: 7.3

Q5:
E: 0.0
B: 0.7
C: 0.1


Something is obviously horribly wrong, as nothing is working correctly in the BBD section. There is no difference in audio signal if I remove any/all of the chips besides the 4558.

Help!

Zach

[natalio]

Take a look at the trimpot!!

[Zben3129]

I tried, 2/3 allows circuit to pass normal audio, other 1/3 just kills entire circuit. No position on the trimmer effects the non-functioning BBD section.

Zach

[Andre]

The voltage on pin1 of both the MN3101 and MN3007 is too low.
It should be only little under the battery voltage.
Please check if R52 is really 33 ohms.
You could also remove the MN3101 and then measure the voltage on pin1 of the MN3007 again.
If the voltage is OK now, you could be right about the MN3101 being defective.

[Zben3129]

I looked at some other threads and found out that my mn3101 is defective. I contacted the seller and he said he will ship me a new one tomorrow, but will not refund me....So I'm thinking I'm just gonna get another crap one. Sweet.

Anyone got a spare mn3101?

Zach