Nrg MC3 rev counter issue

Hi all ive had a few issues with the lights etc on these clocks so i stripped em down to find the plastic printed circuit board was rotten to with a lot of solder and wire to bridge the breaks in circuits etc i got it all working all the lights etc work on the panel fuel,battery gauge works the problem is i turn on the ignition the rev counter flickers but when i start the engine it dont move if this makes any sence to you guys...lol any ideas were the issue could be
thanks for looking

 

water damage mate myn did it got a nuffa set of clocks worked fine

 

For a start on piaggio clocks the rev counter normally flickers the a couple of seconds when you turn it on nut dont know why it doesnt work when the engine is running