Maestro Octave Box troubleshooting help

[SonicVI]

I just got a partially working Maestro OB-1 Octave Box.  The octave part is not working correctly. The octave just kinda pulses for a second, no sustained note.  I've done some audio probing and there is octave division going on after the divider IC (see schematic). I'm getting good signal at all of the preamp stages. I seem to lose a bit of signal at the emitter of Q6.  I believe the problem is in the Q6-Q8 (pick det amp & monostable vibrator) area but I'm not sure how that works.   I think it just detects the guitar signal and allows the octave signal to pass D1 and D2 while there is adequate signal.  If I bypass the diodes with a jumper the octave makes it through but it doesn't really track the guitar frequency very well.  Any help would be appreciated.

Schematic:
http://homepage.mac.com/sonicvi/maestrooctave.pdf

Voltages
V+=9.35

Q6
C-8.58
B-.38
E-.01

Q7
C-8.54
B-.14
E-0

Q8
C-.14
B-.64
E-0

[isildur100]

Is this the real pedal or a build following the schematic? I'm asking because I was wondering if that schemo was accurate since I plan on trying to build it.

[SonicVI]

It's an original pedal.  I haven't found any errors in the schematic so far.  You may have trouble cloning it as the Motorola single flip-flop IC was discontinued in 1975. 

[SonicVI]

anybody have any ideas?  Does the Q8 collector voltage look too low?   Should I just try replacing Q6-Q8 and maybe the diodes too?

[isildur100]

The collector voltage for Q8 looks wrong, can you measure right before that 10k resistor? Are you sure you have 8 volts going to the 220k and 10k resistors just above Q8 in the schemo?

[SonicVI]

I'm sorry, I have Q7 and Q8 backwards up there.  

With that in mind. I get 8V before the 2.2K resistor off Q7's collector and .14V on the other side.  I get 0V on the cathode side of the diode off Q7's collector.

[SonicVI]

I pulled and tested Q5-Q8 and the diodes and they are all ok.
I get the same voltage at the collector of Q7 as the base of Q8 (.14V) despite a 220K resistor being between them, which doesn't seem right.

[isildur100]

Yeah this is strange. I wish I could help you more

All I can say is check for continuity between those connected components, maybe a trace is damaged. Check or replace those resistors (the 2.2k and 220k) and make sure they are really connected to the 8v and to the tranny collector etc.