Help debugging Variax 600

[mkoslowski]

Hi everyone,

 

Short story:
I've got a "not working" Variax 600 from a friend to try to fix it.
The problem is that the guitar is not able to save any patch.

Long story:
My friend got the guitar 2nd hand from a local store. It played fine for a few months and started malfunction (low volume in some strings, no sound sometimes and so on..)
He took the guitar to a repair center pointed by Line6 and after 7 months they returned him the guitar saying it was Ok. It played for a few weeks and stop making sound again.

One month ago he gave me the guitar to try to fix it and when I opened it I found the battery cables squeezed between the metal cage and the guitar body and one of them was broken.
After changing the broken cable the guitar started to work again. Then, when I tried to change patches and save them the guitar stopped making sound and was hung until I re-powered it again.

What I tried so far:
- Edit and Save patches, I tried 2 methods:
   - Variax USB Interface
    The guitar will connect, sync, and I can edit any patch and hear the sound changing (connected via P10 to Amp)
    When sending the modifications back to the guitar (to save it), workbench hangs and the guitar no longer plays any sound in the amp.

   - Using the method described in the user guide, where you select the patch to be copied, hold the model knob down, rotate it to the target and releases it.

    Both ways, the guitar stops playing  any sound in the amp, and I need to turn it off and on again to get the sound back.

- Check with the oscilloscope if the Write Enable pin on the flash memory was being driven by the processor, and it was only driven when the guitar was not hung.

- I also checked with the oscilloscope other pins (data, clock, power and piezos) and everything seems to be working.

- Yesterday, I carefully removed the flash memory IC and soldered a new one. I was hoping that the flash memory had only data (no code) and so I would be able to write that data back through the MIDI channel (the same that is used by WB to change patches). With this new blank flash memory, the WB does not find the guitar through Variax USB interface.

Questions:
- Does anyone from Line6 can help me recover this guitar?
- Does anyone have a raw dump from the flash memory? if so I can write it to a new one and solder it! (I still have the original flash, but who knows if I will be able to read "good" data from it)
- I also want to try to force an update through the MIDI channel. To do so I need someone with a working guitar to get a log from the WB. Anyone can help me getting the log file?
 

If you need any more details, please ask!

Sorry for the long post.

Thanks,

 

Mikhail