Weird science/electrical issue

[Mike Wilkins]

I have a Bosch VS 3/8" corded drill with a funny issue.
Holding the drill upright it works fine.
Turn the drill on its side and nothing. Squeeze the trigger and nothing.
Do the usual-check the plug. Yes, plugged in.
Something makes me think there may be a brush issue inside the thing. Have had it over 20 years with no issues.
Also, no UFO activity in the area lately.

[Tom Giacomo]

Probably brushes are worn out.

[Charles Lent]

Likely worn brushes, but sometimes a break in the power cord can do this. They usually break very close, within a couple of inches of, the entry point near the handle. Position the drill so it runs and then without moving the drill, bend the drill end of the power cord in multiple directions. If it keeps running during this your problem is most likely the brushes.

Charley

[Steve Baumgartner]

I'd go with the power cord theory first, since you can easily test it as Charley says without opening anything up. It is very common for the flexible wires to fatigue and break right where the cord enters the strain relief at the drill. Tipping on the side most likely flexes the cord at that spot and breaks the circuit. I won't rule it out, but I haven't experienced worn-out brushes causing a tip-sensitive total failure.

Steve

[Brian Tymchak]

I'd go with the power cord theory first, since you can easily test it as Charley says without opening anything up. It is very common for the flexible wires to fatigue and break right where the cord enters the strain relief at the drill. Tipping on the side most likely flexes the cord at that spot and breaks the circuit. I won't rule it out, but I haven't experienced worn-out brushes causing a tip-sensitive total failure.

Steve

I had a reconditioned cordless drill do the same. I suspected brushes, but since the spindle was slightly bent (or the chuck was misaligned somehow) I just dumped it without dissecting it.

[Patrick Grady]

Probably in the power cord. Brush wear a good second suspect. Brushes can fail in a number of different ways depending on their construction. If a brush has failed in an intermittent way, then continuing to operate the drill might cause damage to the commutator. I would take the drill apart immediately. Also most any brush can be replaced even if stock replacements are no longer available.