Doepfer

by CD I mean of course the CD4069

Hi

I don't know if this adds anything helpful, but I have a Yamaha DX7II from the 1980s that stopped working about a year ago - no lights or anything when I plugged it in.  Yes, I thought it was a blown fuse - but it wasn't.
I did a LOT of research on the web, which pointed me in the direction of the capacitors in the on-board power supply.
I replaced these for few £s, and the synth powered up as new.
So, if there are a few electrolytic capacitors [they show a '-' (negative) on one side] and you can replace them [needs soldering] that would be the first type of component I would suspect, as they do die with age (like us).
If you can't solder, you will have to find someone who can.

Hope this might help.

Stu


--- In Doepfer_a100@yahoogroups.com, <mantzster@...> wrote:

>
> by CD I mean of course the CD4069 
>  
> 
> ---In doepfer_a100@yahoogroups.com, <mantzster@> wrote:
> 
>  Hi All, 1st message and it's a plea for help  As the title say my Wasp is no longer working, I had it out of the case, and on putting it back all I get out is the original audio from the HP out ie. the HP/LP balance acts as a volume control. Nothing from the BP out either, and the Freq & Res controls have no effect on the audio I can hear via the HP.
>  Swapped out the CD as I understand this can be vulnerable, no change. Tried swapping out the 2 CA3080s one at time, again no change. Only thing I haven't swapped out is the 5532. No obvious signs of shorts / crack damaged components. What's the next step? Do have some electronics experience and a multimeter 
>  
> 
>  cheers for any advice.
>

> Hi All,
> 1st message and it's a plea for help  As the title say my Wasp is
> no longer working, I had it out of the case, and on putting it
> back all I get out is the original audio from the HP out ie. the
> HP/LP balance acts as a volume control. Nothing from the BP out
> either, and the Freq & Res controls have no effect on the audio I
> can hear via the HP.
> Swapped out the CD as I understand this can be vulnerable, no
> change. Tried swapping out the 2 CA3080s one at time, again no
> change. Only thing I haven't swapped out is the 5532. No obvious
> signs of shorts / crack damaged components. What's the next step?
> Do have some electronics experience and a multimeter
>
> cheers for any advice.

in 95% of all cases the problem can be solved by replacing the integrated
circuits (as you did). I'd recommend to replace the NE5532 too. If this does
not help take a look at the two transistors Q1/Q2 - especially if the pads
are still connected to the pcb tracks. It happens now and then that the pads
are damaged by applying an excessive force to the transistors. If you cannot
find the fault the module has to be sent in for repair to the dealer where
you purchased the module.

Best wishes
Dieter Doepfer