Tach/ dwell TDS3 tester quit working

[gunnerb17]

Tach on my TDS3 tester quit working. Tach cable from plug to board inside tester checks good.I have the lead with the split sleeve clamp on end for plug wire.Any help is great.Iam sure any parts will be hard to come by.Dwell part of tester works fine.Many Thanks

[wesk]

Do you have the original owner's manual that came in the case? If not you can try this manual for the AUL version which is the Same FSN as the Simpson:

https://www.liberatedmanuals.com/TM-9-4 ... -and-P.pdf

[gunnerb17]

WES K --I dont have the original manual but I wish I did.I printed the one out that you posted.It looks real good.I believe it will help a lot.Thanks Again