Casio CZ/ VZ/ FZ - Pro Series

This is what I have found out:
The processor appears to be operating. The digital and analogue supplies appear to work,since moving a potentiometer sends a voltage to the analogue inputs of the processor,this then sends out transmissions on the tx pin (17) and it even makes it to the MIDI out although seemingly at not a sufficient level to generate MIDI,it does flash the LED on my MIDI/USB cable - but not the correct colour. I am wondering if the output stage tranny is fouled.
The whole front facia does not light up,I have not located the LED power,but there is a 'backbone' ribbon cable of the type that tends to break when bent,which I am about to beep out to see if it is intact.
It seems the machine is operational ,but just not indicating what it is doing,or producing MIDI strong enough to be noted AS a midi signal.Indeed I read on a forum that someone else had an AZ1 with power light on and producing MIDI but not showing any LED action. It is suggestive of the LED power or ribbon cable being at fault.

At least there is hope if the processor is not dodgy and doing what it should.

      From: "Daniel Forró danforcz@... [CZsynth]" <CZsynth@yahoogroups.com>
 To: CZsynth@yahoogroups.com 
 Sent: Friday, 23 October 2015, 13:46
 Subject: Re: [CZsynth] AZ1 repair
   
    Then I would start to check all circuits delivering the power - there's one for digital circuits, another one for analog circuits, third one for LEDs. Maybe something is wrong there.
Service manual describes some voltage settings on page 28, and troubleshooting starts on page 30.
Daniel Forro

On Oct 23, 2015, at 9:39 PM, Lee Borrell templarser@... [CZsynth] wrote:


Diag is not going to get too far without anything lighting up - it is as though no power is coming from the PSU PCB - yet the power light is on. It is possible for everything but the power LED to get power.
I have asked the seller what the history is - that may shed some light - otherwise I'll have to go in and see where the power is and isn't.