Ibanez 150 delay problem....help?

[MartyMart]

I've got an old Ibanez 150 analog delay, its the large "amp top" box, about 2/3 rack sized.
It powers up fine.
Dry signal is passed fine.
Delay signal is "almost" working, but only with "zero" repeats/regen
as soon as I "dial up" a few repeats they "feedback" and howl forever !!
So:
1 - I dont know much about delay circuits as yet !
2 - I reduced the "regen" trim pot inside --- no change
3 - On the board I have these trimmers:
regen
level
peak level
clock low
clock high
clock width
7.5v
IV    ?
balance
4 - also 3x 4016's 1x 4013 1x 4069 3xJRC4558's 1x MN3005 1x NE70N
There's no damage to the unit, no burnt out parts or bad connections that
I can see with my mag-glass.......
Could it just be that my "Repeats" pot ( 50k ) is bad and is therefore jumping to maximum repeat at the slightest turn ! ??
Any other experience/ideas folks ?    

Help greatly recieved as I'd love to have this one working !!

Marty.

[MartyMart]

BUMP !
No one ?
It seems that someones "had a go" with the trim pots !!
I've made a few adjustments ( clock width mostly ) and its almost back to life !!
Still have a bit of a regen problem and a "degraded" delay signal.....
hmmm   ADVICE ??..... settings...... voltages/areas that are important ?

Thanks,
Marty.

[walters]

1.) could be your Trim pots are broken inside the wiper
               is not turning, maybe change them


          2.) See if the Feedback pot is the Same value as on the
               schematic if its not the same value thats why its
               oscillating

[ExpAnonColin]

It (obviously) sounds like something is wrong with the feedback path itself.  If you can't find the problem, try messing with the value of the pot, or adding resistors in series.

-Colin

[StephenGiles]

3 x 4016 eh! Could this be another PWM delay?
Stephen

[Maneco]

I'd like to see pictures of the boards,maybe i can trace the schematic and help you,but i second the trimpot suggestions...