Tacho not working sv650 X 1999

[nickpowell]

Hello SV650 people

I've just finished restoring my Son's SV and it rides sweetly for a bike of 23 years vintage.

Everything works apart from the Tacho. (rev meter)
I'm into electronics a bit as it was my trade so measured the incoming signal on a scope from the ECU and it seems to vary its frequency upon changes in revs which suggest the signal is good.

The mechanical dial doesn't move at all. I can't see any signs of physical damage, the shaft doesn't wobble and the needle returns to zero if manually moved.
I can see that one of the resistors has got rather hot so plan to replace this but I have no idea as to its Ohm rating as its black!

Two questions please:
1. any clues as to where to get a new tacho? ( Ive tried Ebay for a bit)
2. Any other pointers.

Ta
Nick