Zoom 9120 LCD

Bit of a long shot...But I have a Zoom 9120 Rack FX. It's my main  thing for reverb etc.
But the LCD has lost its LCD backlight and it's difficult to see the LCD text without it.
I've pulled it out of the rack to see if there was any change by moving the rear panel LCD CONTRAST control did anything.
It does in the sense of 'blurring' the text but no sign of a backlight. I've looked for anything obviously wrong and reseated the connectors at LCD and PCB end.
So if anyone should happen to have a schematic or any service info' then that would be good.
Although if the LCD board is the problem it's unlikely to still be available (rather old unit now).

Anyway - if anyone can help or advise it would be very much appreciated.
Thanks for reading.

Some photos of the thing might help. The LCD might even have some part number on it.

Sorry can't help much but did you ask here
https://www.facebook.com/groups/music.gear.display.retrofits/

The 9120 is a great, natural sounding reverb that is easy to  tweak the patches on.  Weird they go for no money.  I must have had mine for must be 20 years now & only paid 80 quid for it then.

Khron said:

Some photos of the thing might help. The LCD might even have some part number on it.

Click to expand...

Hi. Yeah - it has a PCB number on it but given the age - I think I got it in the 90s and it was one of the last retail units it's not a great deal of use. But see my reply to Rob Flinn for update...

Rob Flinn said:

Sorry can't help much but did you ask here
https://www.facebook.com/groups/music.gear.display.retrofits/

The 9120 is a great, natural sounding reverb that is easy to  tweak the patches on.  Weird they go for no money.  I must have had mine for must be 20 years now & only paid 80 quid for it then.

Click to expand...

Thanks. So as it happens I accessed the pcb itself with aim of taking photos as suggested by Khron. But then the backlight sprang into  action, So seems a mechanical connection thing. maybe a dry joint after all these years. The backlight is simply a light on one side of the display module.  Half the display stilled seemed in 'shadow' but I could see that that was due to the lie of a cable within the display module. I thought I'd be able to shift it such that it would be out of the way. But there's a transparent plastic (I guess) barrier that stops me moving it so can't really do anything on that without risking the whole display itself.

So I'll go with it as it is atm. Thanks for the tip to that Display site - I love that sort of community. I requested to join the group but not yet heard back. And yeah - it's a pretty cool unit if you're not hung up on high resolution / sample rate specs'.  I got mine 'new' but it was one of the last in stock from what was a major retailer based in  IIRC Nottingham UK and it came minus the rack ears so I've 'improvised' around that.

I had two 9120's at one point but swapped one for a DBX 164.  The sample rate isn't a big issue for me.    I have some other reverbs that are much more upmarket, but I still like the reverbs on this unit a lot.  It was something like £750 RRP when it first came out, which was quite a pile of dough back then.  Zoom also did a pro specced reverb with xlr in and out, but I think it was only available in Japan because I have never seen one over here.

One thing I have always contemplated is fitting an internal PSU & i.e.c because there is bags real estate in the case.

Newmarket said:

But then the backlight sprang into  action, So seems a mechanical connection thing. maybe a dry joint after all these years.

Click to expand...

It might be a bad contact, solder joint or wire, I would recommend you to clean all connections and re-touch all solder joints.

Another thing to think is sometimes LCD's in FX processors loose the light because of shot electrolytic capacitors in the LCD circuit.
I repaired some Yamaha FX processors with the same issue where the problem was related to dead Lytic caps.
I don't remember the Yamaha model name at the moment but I searched online at the time and it was a known issue.
Replacing all the Lytic caps in the LCD circuit recovered all the lighting.

Regards