can a tech offer their help?

[rev mex]

I'm getting to the nuts and bolts of my problem. I have a request.
Testing around has brought me to IC 4023 which is in 13E.
I'm visually noticing that there is a ripped off trace that once connected pin 3 and 12. Holding up a light under the board confirms that.
The schematic (Service manual 1.0) says that pin 2 and 12 should be connected.

Which one is correct?

If you so happen to have a drumulator board open, can you let me know which one beeps continuity when touching both IC pin points?

-Rev

[Dynamikk]

Hi Rev,

I'll have a check when I get home tonight!

/Dynamikk

[Dynamikk]

Pin 2 and 12 are connected on my PCB (just like the manual).
Where do you see the ripped trace? Under the 4023 (13E)?

/Dynamikk

[rev mex]

Pin 2 and 12 are connected on my PCB (just like the manual).
Where do you see the ripped trace? Under the 4023 (13E)?

/Dynamikk

Yes I unsoldered the 4023 ic and noticed the connection was gone between 2 and 13. I wish I could post a pic. The reason I ask is because I see evidence from the board print that there a connection from pin 2 to 13. I?m going to go back to the schematic if you?ve confirmed that it should be 2 and 12.
Appreciate it.

-Rev

[rev mex]

Well I learned how to upload an image. As you can see 2 is not connected to 12. 3 was connected. I?m totally confused. It sucks soldering and unsoldering.

-Rev

Pin 2 and 12 are connected on my PCB (just like the manual).
Where do you see the ripped trace? Under the 4023 (13E)?

/Dynamikk

Yes I unsoldered the 4023 ic and noticed the connection was gone between 2 and 13. I wish I could post a pic. The reason I ask is because I see evidence from the board print that there a connection from pin 2 to 13. I?m going to go back to the schematic if you?ve confirmed that it should be 2 and 12.
Appreciate it.

-Rev

[Dynamikk]

Hmm...strange.
What kind of issue do you have with your drumulator?
Still the freeze when trying to record a pattern?
What PCB revision do you have?
Serial number?

My Drumulator works fine except when I press the Copy/End button...then the Drumulator freezes.
I've just received some spare parts so I guess I'll try to get it up and running pretty soon...I hope :-)

/Dynamikk

[rev mex]

the board says - 11/30/1982
serial: 1710

at this point i cant turn it on. I'm trying to get it back on.
I made things worse when i removed this IC.

I'm wondering if there are other service manual version out there besides 1.0

-Rev

Hmm...strange.
What kind of issue do you have with your drumulator?
Still the freeze when trying to record a pattern?
What PCB revision do you have?
Serial number?

My Drumulator works fine except when I press the Copy/End button...then the Drumulator freezes.
I've just received some spare parts so I guess I'll try to get it up and running pretty soon...I hope :-)

/Dynamikk

[Dynamikk]

Hi Rev,

I just checked my PCB again and it actually beeps continuity between 2-3-12
If you look under the PCB pin 2-3 are connected with a trace, and I guess that 3-12 are connected under the 4023 on the other side of the PCB.
So if you don't have a connection between 2-12 I guess the trace on that side of the PCB has been damaged.

My PCB is also marked 11/30/82

/Dynamikk

[rev mex]

Hi Rev,

I just checked my PCB again and it actually beeps continuity between 2-3-12
If you look under the PCB pin 2-3 are connected with a trace, and I guess that 3-12 are connected under the 4023 on the other side of the PCB.
So if you don't have a connection between 2-12 I guess the trace on that side of the PCB has been damaged.

My PCB is also marked 11/30/82

/Dynamikk

awesome. that'll work!
Can I bother you for one more pin check?
Same 4023 chip (13E) pin 9 and/to pin 20 on 13K
I don't get a beep but I think I should. It may be another dead trace from one point to the next.
I really appreciate all the info you've given.

-Rev

[Dynamikk]

Yes, they should definitely be connected, also 13E pin 10 to 15K pin 20.
I'm glad I can help