Bad piezo or short on B string

[Gelphledor]

Hello everyone i'm new to this board after discovering the old parker board has vanished
I have a 1994 hardtail deluxe that recently developed a severe 60 cycle hum whenever the peizo pickups are engaged and it seems to be just the b string that is causing the issue if i depress the b string against the frets the hum goes away ,i have never had a saddle off and not sure if any local techs are familiar with parkers,i'm pretty good fixing most things and if its just a solder issue i may tackle it .

the only other issue i have had was the input jack becoming missalinged from tightening it many times over the years from the outside only,this made the contact points on the plug not seat " just had to spin the the outside of jack out and tighten the inside nut when the length was right again"

[vjmanzo]

Hi @Gelphledor; welcome!

I've encountered this issue before and have been able to solve it a few times simply by changing the strings. The piezo element in the saddle needs to be as close to the string as possible to make good contact and if it's not seated properly in the underside of the saddle, it can cause a hum or simply no output at all.

On a 94 Deluxe, you likely have what we're called the "screw saddles" as shown here. You might try blowing some compressed air on the saddle the next time you change strings. If the problem began as the result of a string change or some sort of intonation adjustment, I'd say the problem might be worse, but, in my experience, it's likely due to the string getting old.

#PiezoIssues

[Gelphledor]

i loosened the b string and removed the hex screw then gently lifted the saddle piece and had a peek with flashlight,could not see much but the wire seemed secure so i hit it with compressed air and a tiny blast of Deoxit D5 reassembled and it seems to be ok now,thanks for the tip and will repost if the issue returns.

[vjmanzo]

That’s such great news, @Gelphledor! Glad this worked out for you!

[schrectacular]

Hi,

I'm suffering a similar problem on my '06 Fly Mojo. I sent it to my tech with an issue on the G string - piezo worked, but if the string is bent, it cuts out. My guy has looked at the board and everything looks fine... but since he restrung now we get no sound at all.

Any suggestions on what he could try? Is it possible to source a new board? Does he just need to fiddle with it and spray some air in there and just try to reset the strings and see if that helps?

Any advice welcome!

[vjmanzo]

Hey @schrectacular and welcome!

It sounds like the Piezo element (underneath the saddle) is just not seated properly in there. You could hit it with compressed air and see if that fixes it, but it sounds like that’s where the problem lives. sometimes the particular brand/material of the string or even a string gauge can be the issue, so I wouldn’t be shy about trying that as well.

The piezo elements themselves are really small—for reference, here is a photo of some of the elements we affixed in the saddles of the 12-string Fly:

Keep us posted!

[mmmguitar]

+1 to VJ’s suggestions. Considering the element is just epoxied into the bottom of the saddle with a single wire soldered to the “summing board” on the underside of the bridge, the point of failure resulting in intermittent or total signal loss in a single string would have to be limited to the element itself or its wire. If you tap the saddles and get sound out of every one but the G, it may be cause for saddle replacement (if no other cause for signal loss is apparent).

[schrectacular]

Awesome tips, thanks y'all! I'll be calling my tech tomorrow and I'll let you know what we find.

He already touched the element with a bit of solder to see if it was loose in that respect, but no go. I'll definitely tell him to try some air and some contact cleaner and to just fiddle with it and we'll see.

I'll definitely report back.

[schrectacular]

So after fiddling with it for ages, my tech actually got the G string working much better than it ever had. I could bend quite a bit more before it cut out and I was really happy with it. He said he had to bring it out of tone just to get the pickup to engage right. He tried everything, spraying with air and contact cleaner, but only actually physically adjusting the strings made a difference.

But I think it didn't like some whammy bar shenanigans I was doing because now it's even worse, no sound at all unless I bend the bridge down quite a bit. Kind of sad to have it being better, then worse. Alas.

But the guitar is set up great now and it's a joy to play. I don't use the piezo feature that much anyway. But I'm sure I'd use it more if it worked...

I wish I knew how to get in there and fix whatever is broken. It feels like something is just not seated right within the pickup itself. Works if the angles are just right. Very strange.

[vjmanzo]

Hi @schrectacular--what kind of strings are you using? Brand and gauge?

[mmmguitar]

Very curious about what the problem ends up being. If you’re getting a piezo signal only when the bridge is being tilted, my first thought is that something in contact with the summing board solder or a slacked wire with the bridge in “zero position” is shorting the signal. Hopefully it ends up being something that simple/frustrating. I’m with VJ in hoping it ends up being a string issue, but under-the-hood gremlins can sadly never be ruled out when it comes to symptoms that leave you scratching your head.

For what it’s worth, going Graphtech with everything would be a permanent solution (each saddle is an element embedded in composite, leads are plugged in to summing board in control cavity instead of soldered to underside of bridge, etc.). It’s not the cheapest solution, but neither is paying a tech to chase gremlins for months.

[Patzag]

What kind of saddle do you have on your Mojo? @schrectacular

[Fly Rod]

Have a look at this link, There are a few Parker related problem fixes, One is the issue I think you might be having..
The string may not be making a ground at the bridge due to a painted string ball..
http://jmstaehli.com/guitar_css.html?fb ... NOzAEKJBa8

Newer made D'Addario String Balls are anodized instead of painted & Should allow for contact at the bridge
A way to check is as stated in the link to allow excess string at the tuner end to touch the next one or twist together to check
Says something about some have something in the bridges string hole? I was thinking some of that copper foil tape I have for shielding control cavities..
Just another Idea floating threw my head..

[schrectacular]

Sorry all for taking so long to get back. The issue comes and goes, especially when I use the whammy bar. I still am struggling with it.

@Patzag

http://jmstaehli.com/guitar_css.html?fb ... NOzAEKJBa8

This is very interesting. I tested with a multimeter, but the string is connected to the other strings and this doesn't change even when it cuts out. It seems like this would rule out the issue described in the above post.

[billy]

Piezos need pressure to work properly.

Since your issue is intermittent, I would guess that it is either a problem with the wiring, a loose saddle element, or something underneath the saddle preventing consistent contact.

I would try removing the saddle and cleaning both the saddle and the bridge's mating surface.

Check to be sure the saddle element is not loose. If so, and you get it to work, you might be able to use a little ca glue to hold more securely in the right position.

[schrectacular]

Super late reply... sorry for that... I suppose this could also be made better by using heavier gauge strings. I never noticed it when I had 10's on there.