GK- No normal guitar output through 13 pin cable

Started by batman, July 24, 2016, 01:59:14 AM

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batman

I took my strat in for some servicing to fix up my dodgy mounting of the GK3 internal kit.  It's worth noting everything worked fine before I took it in.
Now I don't have any signal from the normal pickups coming out through the 13 pin cable.  It's definitely a problem with the guitar because I get sound tapping the pints on the 13-pin cable when I pull it out.
I've spent the last few hours going over everything with a multimeter and can't seem to find a single problem; it all appears to be wired up correctly (and the hex pickup works fine).  Could I have missed something?  It's driving me mad!
I don't get continuity between the 13-pin guitar output (pin 7 - normal guitar out) and the pickups; but I think there is an op-amp on the circuit board so this is normal, correct?  There is continuity between the pickups/6.5 mm jack and the corresponding pins on the GK3 board.
Is it possible the op-amp or something else on the board has blown?

Also I get a massive amount of noise when I plug a normal guitar lead into the guitar at the same time as the pickup.  Is this normal (ground loop-type issue?) or could it be related.  Usually I wouldn't do this but my "sound" is a blend of the normal guitar signal through an amp and the hex-pickup through the PA.
Thanks

gumbo

If you are using a switching (1/4") jack, (as in the Roland-Ready Strat) check the switching contacts on it...

Peter

See also:  https://www.vguitarforums.com/smf/index.php?topic=17585.0
Read slower!!!   ....I'm typing as fast as I can...

Elantric

#2
You may have a bad Output Jack

Its a switching type jack  - actually the same type used as an Input jack on old vintage Fender Twin reverb amp

When this Jack's switching elements go bad, the Roland Ready Strat's mini three way toggle may act non-functional.


This arrangement of using a switching output jack is unique to the the Fender Roland Ready  / GC-1 Strats  - and different than Roland Gk Internal kits.

The goal of the switching Output Jack is when the 1/4" Guitar cord is connected, this will  completely remove the entire Roland GK circuit from the normal guitar output path. 

* Remove the Jackplate and verify the contacts are clean on the SWITCHING OUTPUT JACK. If these contacts become dirty, much noise can be introduced or worse, complete failure of the normal guitar sound passing thru the 13 pin cable. Most Roland Ready Strats older than 5 years will suffer contact failure on this unique 1/4" switching jack. (Hint: This is the same switchcraft type switching jack as used on a 1960's Blackface Fender Twin Reverb Input Jack



batman

Thanks but it isn't a RR strat.  Just a normal strat I've installed a GK-KIT-GT3 in.  It doesn't have a switching jack - only 2 contacts (ground and signal).

It worked fine before I took it in but now it doesn't.  Could it be anything besides the Roland circuit board?  I don't want to buy another one and find out it still doesn't work.

Is there a way to test the Hi-Z to Lo-Z preamp/conversion on the Roland board?

admin

#4
QuoteThanks but it isn't a RR strat.  Just a normal strat I've installed a GK-KIT-GT3 in

GK-KIT-GT-3 thread is here - explains most troubleshooting and debug procedures
https://www.vguitarforums.com/smf/index.php?topic=133.0

I understand you are using a GP-10

suggest back up your presets and then perform a GP-10 factory reset to see if the normal guitar pickups are restored  - you should be able to hear them on GP-10 factory presets 80-89

batman

Thanks but the GP-10 is fine.  I have another guitar with the external pickup and it works.

gumtown

QuoteI don't get continuity between the 13-pin guitar output (pin 7 - normal guitar out) and the pickups; but I think there is an op-amp on the circuit board so this is normal, correct?
Yes there is an opamp buffer to convert the Hi-Z input to Low-Z to keep the noise low through the GK cable.

Check the wires to the 3 position toggle switch, in particular the shielded pair, as this is shorted to kill the normal P.U. in "synth only" switch position. Maybe unsolder this from the switch and check it is not short circuited.
Free "GR-55 FloorBoard" editor software from https://sourceforge.net/projects/grfloorboard/

HecticArt

Can there be issues if the GK wires going to the 1/4" out aren't connected to the right contacts? As in, connected to tip & sleeve instead of sleeve & tip?

batman

Quote from: gumtown on July 30, 2016, 03:23:08 AM
Check the wires to the 3 position toggle switch, in particular the shielded pair, as this is shorted to kill the normal P.U. in "synth only" switch position. Maybe unsolder this from the switch and check it is not short circuited.

Gumbo you champion.  It turns out there was a short.  I have no idea where it was but I unplugged and plugged in a few things a few times and it went away.
However it still didn't work; but you're post got me thinking and I suspect that something inside the guitar was shorting on the new shielding paint in the cavity.  A few random bits of insulation stuck in there has appeared to solve it!  I'll sort out a more permanent fix later.
I didn't mention the shielding paint initially because I didn't think it was relevant.  Obviously I was wrong :)

gumbo

Quote from: batman on July 31, 2016, 01:03:42 AM
Gumbo you champion.  It turns out there was a short.  I have no idea where it was but I unplugged and plugged in a few things a few times and it went away.
However it still didn't work; but you're post got me thinking and I suspect that something inside the guitar was shorting on the new shielding paint in the cavity.  A few random bits of insulation stuck in there has appeared to solve it!  I'll sort out a more permanent fix later.
I didn't mention the shielding paint initially because I didn't think it was relevant.  Obviously I was wrong :)

To be fair, credit where credit is due..  ...that was GUMTOWN, not me..

...although that was the next thing I was about to suggest.. ;)

Just good that it's all fixed!

Cheers,
Peter
Read slower!!!   ....I'm typing as fast as I can...

batman

Haha sorry Gumtown!  You guys have both helped me out now anyway so cheers to you both :)

DrD

Apologies to tack onto this thread, I am new to the forum and just fitted my first GK-3 to my stunt double Les Paul. No issues with fitting or with playing synth functions (position 3 for presets 1-48 and position 2 for presets 49 + 50 of the SY1000). There is no output for presets 49-50 from position 3 as expected. However, there is no guitar output from position 1. Tried all the obvious : exchanged jack/jack to GK-3 cable, tried two different Boss 13 pin cables with same result.  The guitar output direct to a Boss Katana amp or Helix unit is fully functional.   Is this a common problem or am I just unlucky.  I have another 13 pin cable on order just in case !

Thanks for your patience, I did not know where else to post this query.

Chris

Elantric

#12
Quote from: DrD on April 02, 2023, 02:17:05 PMApologies to tack onto this thread, I am new to the forum and just fitted my first GK-3 to my stunt double Les Paul. No issues with fitting or with playing synth functions (position 3 for presets 1-48 and position 2 for presets 49 + 50 of the SY1000). There is no output for presets 49-50 from position 3 as expected. However, there is no guitar output from position 1. Tried all the obvious : exchanged jack/jack to GK-3 cable, tried two different Boss 13 pin cables with same result.  The guitar output direct to a Boss Katana amp or Helix unit is fully functional.  Is this a common problem or am I just unlucky.  I have another 13 pin cable on order just in case !

Thanks for your patience, I did not know where else to post this query.

Chris

Verify you have the short 1/4" cable from normal guitar output feeding the 1/4" input on the GK-3


SY-1000 GK-3 three way switch functions
https://www.vguitarforums.com/smf/index.php?topic=30399.0

DrD

Thanks for the rapid response !  Yes, indeed I was using the supplied 1/4 to 1/4 short cable that came with the GK-3 pickup then tried another high quality 1/4 to 1/4 short patch cable then a short length 1/4 to 1/4 guitar cable in case there was a problem.  Synth sounds are great just no guitar from the guitar only GK-3 switch setting.  The GK-3 booklet does not provide any useful information.

Regards

Christopher

Elantric