Potentiometer problem on Chinese 40w laser.

[cropwell]

I presume that, if you can say the markings are illegible, you can get to the pot. Is it possible to measure the resistance at the ends and check that the resistance changes smoothly from zero to max when you meter across the end and the middle and operate the knob. (power off, of course).

If it is the pot, then the symptoms you describe are strange. Normally I would expect a burnt or worn track where the wiper made poor contact, or some sort of short.

Note that other components could cloud the results, so it would be best to check the pot when it is out of the circuit.

It would help if you could tell us the make and model of the laser.

Cheers,

'Doc'

[andyisko]

I presume that, if you can say the markings are illegible, you can get to the pot. Is it possible to measure the resistance at the ends and check that the resistance changes smoothly from zero to max when you meter across the end and the middle and operate the knob. (power off, of course).

If it is the pot, then the symptoms you describe are strange. Normally I would expect a burnt or worn track where the wiper made poor contact, or some sort of short.

Note that other components could cloud the results, so it would be best to check the pot when it is out of the circuit.

It would help if you could tell us the make and model of the laser.

Cheers,

'Doc'