Delayed Start of the Motor in Electric Trimmer

[Boris_yo]

Hello. The issue is this hair trimmer. It used to start with one second delay until it got to over 10 seconds. Yes I have been spraying electric contacts cleaner or rubbing contacts with IPA 99%
but soon the issue would return. Here's a link to the video:
https://streamable.com/m4i9n4

I wonder what causes it. The battery installed is a single lithium AA at the moment. It happened with alkaline too. But once it starts and I turn it off again and then on it then works with no delay.

[Kim Christensen]

Usually with these kinds of things it's a gummed up mechanical problem. Does it start if you tap it on the counter?
Might just need some cleaning and lube on the cutting blades and motor shaft.

[Boris_yo]

Does it start if you tap it on the counter?

Actually it does but not always. I tried spinning battery in place and whenever I reached certain directions the motor would either start but work not at its full power or start and work at its full power. I would then spin slowly again and it would either stop or slow down from full power. There is no gap between contacts so I wonder why.

[Kim Christensen]

Lightly buff the contacts with a fine abrasive such emery cloth or brillo pad. There might be a bit of oxide/contamination on the contacts. This can happen to the battery too.

[Boris_yo]

Lightly buff the contacts with a fine abrasive such emery cloth or brillo pad. There might be a bit of oxide/contamination on the contacts. This can happen to the battery too.

Will this happen again after I buff the contacts? The device is stored in bathroom's cabinet but compartment has the O-ring and is tightly closed.

[Kim Christensen]

Yea, you'll probably have to do it again eventually. Just don't over do the buffing as most contacts have a thin layer over the base metal that you don't want to wear away. Just buff until they are shiny and then stop.