moonsai98

One more question is if I follow the battery cable’s + and - and solder the led with a resistor, will it light permanently as I always connect the battery pack. Should  I solder the + somewhere that the power will only provided after inserted the guitar cable. Thank you. 

Many thanks and I will try this in the coming weeks (as I need to find the resistor). 

Fantastic! How you connect the led to the main board or the power supply ? 

Yes, Jaropda is correct. Original WB able to adjust the string volume individually. Thank you. 

Just to emphasise Variax 600 uses the original Workbench (Not HD Workbench) and it does not have the capability to adjust the volume of individual string. Only HD Workbench able to do this but It does not support Variax 300/500/600/700. 

Not sure whether it’s too late for you guys as I just saw this thread. 
 

I owned a 500 and a 600.  With the 500, same sound faded out and sometimes in-and-out, especially using the XPS. Eventually I fixed the problem by spraying WD40 over the entire circuit board and all switches (you need to spray a lot like soaking it with WD40). It’s been over a year and still working good no matter with battery or the XPS. 
 

With the 600, no sound with battery or XPS. I did the same trick by spraying WD40 on the mode selector (soaking with WD40) and the same miracle happened.  
 

If the faulty 500 still with you guys, it’s worth to give it a try as i worked for me.