Need help with PM2

[adutton]

I recently purchased a Model C with a PM2. The monitor was working well for a while but then would intermittently stop recording stokes. Sometimes I could just keep rowing and it would eventually pick up again but most of the time it just didn't work. All the features and the display work fine. For reference, the serial number indicates it was made in 1994.

I put in new batteries and noticed that there was some old corrosion (must have been from previous batteries because the ones I took out were pretty fresh). That didn't seem to make a difference.

I tried all of these but they didn't make a difference:

• I took out the cable from the back and re-seated it.
• I pulled out the other end of the sensor from near the flywheel and dusted it.
• I took apart the monitor and blew/brushed off the corrosion.

I am thinking that it might be the sensor cable but I was curious if the corrosion in the monitor may have fried the monitor. In that case I think I'll just upgrade to a PM3. Your thoughts?

[Carl Watts]

Battery leakage eventually causes corrosion that eats through the tracks. An area in the leakage zone below the batteries supplies power to the tach amplifier. I have repaired dozens of PM2's but unless you are in New Zealand I cannot do it for you.

[adutton]

From what I gather, if the amplifier is not working properly, it is highly likely that I'll need to replace the monitor. I will probably attempt the cleaning regimen I've read about on the boards before I purchase a replacement.

I'm in the USA, so I'll be on my own. Thank you for the offer.

[Carl Watts]

The tach pick-up in the flywheel can be tested with just a multimeter. It is simply a 100 Ohm coil of wire. With the multimeter connected wiggle the monitor plug and as long as there is no intermittant breaks at the plug its fine and definatley the PM2 thats playing up.