Grinder turns off when turned at angle - but not wiring fault

[CrazyOatmeal]

I'm fixing an old Makita 9527 that turns on and off intermittently based on the angle it's held at, and recently has stopped working altogether. I thought it was the wire where it comes into the unit, but I replaced that section and it's still dead. I've also replaced the terminal block, which I get about 8 volts across, and the main power inside the unit reads 100 volts (110V model). Everything else inside the unit looks fine. I'm stumped as to what would cause such a weird intermittent failure. Any ideas before I start bodging parts?

[Biggie]

Might be too simple but did you check the brushes.  When they get weak they can cut in and out intermittently for a while until they completely stop working.

[ToolBane]

If you think the angle has a strong effect then definitely there’s a loose connection somewhere where the weight of the conductor, board, or whatever helps it preferentially disconnect as the tool vibrates during use. Trying to visualize what’s being pulled where while you have it pulled apart and are thinking how everything is being shaken at the angle of operation might help you isolate where it is.

[CrazyOatmeal]

I fixed it - it was somehow a problem in the middle of the cable, no idea how that happened since there was no damage, and I already replaced the end near the grinder to a length of about six inches, but oh well.