CASIO PG-380 Electric Guitar Schematics I Seek

Go To Last Post
15 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Hey all,

    A musician friend of mine has asked me to try and repair his CASIO PG-380 electric guitar that has in on board synthesizer.  I replaced all the Capacitors that the interwebs call out as faulty, yet still the synth part is a no go.  I can download the service manual, but they all are missing the pages with the schematics on them....How ironic.

 

My usual Go-To site for schematics is shut down so no luck there either

 

So, I thought I would reach out to the freaks here that play and see if any of them might have said service manual with schematics.

 

Any help would be a great help.

 

JIm

If you want a career with a known path - become an undertaker. Dead people don't sue! - Kartman

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB user

Last Edited: Sun. Nov 12, 2017 - 12:43 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

jgmdesign wrote:
but they all are missing the pages with the schematics on them....How ironic.

...

I look at the world and I notice it's turning
While my guitar gently weeps
With every mistake we must surely be learning
Still my guitar gently weeps

...

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Lee,

YOu using that 'smoker' with something other than wood? wink

 

Jim

If you want a career with a known path - become an undertaker. Dead people don't sue! - Kartman

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB user

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

My Google-fu must be stronger:

http://warningwillrobinson.com.a...

There's a few custom ics in there! Check the obvious (ie: easy) things first. Things like op-amps tend to die, so they're pretty easy to pick. I had the case recently on an old Roland synth that the 2k ram chip died. I only found that by substitution - and after I had tried the micro. Once I'd fixed the ram and got the thing operating, I then found a dead op-amp in the sample/hold circuit. It was a japanese tl072 but in a 9pin sip. A normal tl072 was pressed into service with a few bits of wire. A quick rendition of Depeche Mode's 'just can't get enough' and the job was done.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I found that one as well, but the problem is when you try ans zoom in, all the component values become illegible.

 

JIm

 

EDIT:

Hmmm, Those schematics look better on this PC than the other one I originally looked at them with.

 

Thanks!

If you want a career with a known path - become an undertaker. Dead people don't sue! - Kartman

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB user

Last Edited: Sun. Nov 12, 2017 - 02:51 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Have you tried the Boat Anchor manual archive?  http://bama.edebris.com/manuals/

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

Good find!  Unfortunately it appears that archive is for test equipment.  I am looking for the schematics for an electric guitar with a synthesizer in it.  Kartmans link seems to be the big winner.

 

JIm

If you want a career with a known path - become an undertaker. Dead people don't sue! - Kartman

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB user

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Yeah, a friend told me about Boat Anchor.  I has come in useful a couple of times.  Good luck with your project.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

This should give you the schematic and more - but it's not free.

 

Last Edited: Mon. Nov 13, 2017 - 04:57 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Have you managed to narrow down the problem? I would try scoping the bus to see if the logic levels are ok and if there is a keypad, see if that is being scanned. This is a fair indication of whether the micro is alive.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I have activity on the data lines for the micro that runs the synth board.  Gonna have to do some poking around the other main board and see what happens.

 

Kartman wrote:
Have you managed to narrow down the problem?

Sure.  The problem is the synthesizer no longer outputs any of the pre programmed sounds.  The guitar pickups and those assorted analog circuits work just fine.

 

Jim

If you want a career with a known path - become an undertaker. Dead people don't sue! - Kartman

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB user

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

jgmdesign wrote:
The problem is the synthesizer no longer outputs any of the pre programmed sounds.

Interesting.  So it could be that no sound is "picked" [pun intended] ...

Kartman wrote:
if there is a keypad, see if that is being scanned.

 

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

The keypad seems to be scanned because when I enter a selection I hear an electronic 'click' in the amplifier which tells me that the command was recognised, but nothing else.

 

Jim

If you want a career with a known path - become an undertaker. Dead people don't sue! - Kartman

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB user

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

All keys? If a key is stuck, it might confuse the scan engine.

"Experience is what enables you to recognise a mistake the second time you make it."

"Good judgement comes from experience.  Experience comes from bad judgement."

"When you hear hoofbeats, think horses, not unicorns."

"Fast.  Cheap.  Good.  Pick two."

"Read a lot.  Write a lot."

"We see a lot of arses on handlebars around here." - [J Ekdahl]

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

All Keys seem to work, but for the hell of it I will clean the keys.  Good idea

 

JIm

If you want a career with a known path - become an undertaker. Dead people don't sue! - Kartman

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB user