Hardware Rock Band 2 Fender Stratocaster won't go into Overdrive easily

[HarveyHouston]

Okay, so here's the thing. I bought a Wii Rock Band 2 guitar (like the one in the image below) from Goodwill, along with its corresponding dongle. Everything works fine except Overdrive. In the RB2 manual, it says:

Page four:
NOTE: Tilt the controller neck upwards to go into Overdrive.

Page twelve, under GUITAR/BASS:
When the meter is at least half-full, you can use your Energy to go into Overdrive by tilting your guitar towards the heavens.

With the RB1 Stratocaster, this works flawlessly. But with the RB2 guitar, tilting it up seems to do nothing unless I shake the guitar a little, which can cost me some notes in-game. It seems that the internal accelerometer gets stuck, perhaps from rough handling of the guitar or some idiot spilling something sticky inside. I was just wondering if anyone here knows how to fix it before I take my guitar apart. Is any one else having a similar issue?

Here's what my guitar looks like:

 

[Alexander1970]

Hello.

Sorry to hear that.
I can not really help you since I have this one:

And I do not know if this works in Rockband 2 because I never played it on the Wii (PlayStation 2 with Guitar Hero Guitars).Maybe the GUITAR HERO one works ?

 

[HarveyHouston]

I don't have that one yet. I started playing Rock Band 2 & 3 AFTER the Wii Shop closed, which is why I am hacking those titles. I want to use my RB2 guitar because it has extra USB ports.

 

[Alexander1970]

It seems that the internal accelerometer gets stuck, perhaps from rough handling of the guitar or some idiot spilling something sticky inside.

Maybe thats the reason.

 

[HarveyHouston]

I took the back off my guitar. Nothing appears to be sticky, yet I'm not sure where to look for the accelerometer. Maybe in the fret board?

 

[Alexander1970]

The videos on youtube are terrible....

https://www.youtube.com/results?search_query=rockband+2+fender+stratocaster+disassemble

 

[HarveyHouston]

Okay, so here's the thing. I found that the accelerometer consists of two plastic cylinders taped to a circuit board in the very center of the body of the guitar. Shaking it by hand, some stuff rattles inside (broken parts?). After testing, if I shake the guitar vigorously, nothing happens, but if I slowly raise the fret board, Overdrive is activated. I think what's happening is that there's something inside that makes contact with the bottom of each of the cylinders (made of metal, to be conductive). If I'm shaking the guitar (bouncing up and down, jerking it side to side, etc.), the "stuff" doesn't come in contact and Overdrive is not activated. If I swing the guitar neck sharply, whatever's inside seems to stick somehow and doesn't come in contact with the conductive bottoms.

If the RB2 guitar is broken, then I either need to find an appropriate fix or buy a new one. If this is the way it's designed, it seems very flawed. The RB1 controller "just works", no matter how hard you're shaking it.

EDIT: Probably a capacitive accelerometer is being used, similar to that of the Wii remote but only designed to detect a vertical plane.