Old School PM1 questions

wsucoug9 · Post by **wsucoug9** » June 12th, 2007, 2:33 pm

I picked up a C2 Model B with the old PM1 monitor. From reading around the forum I know I should probably upgrade and retrofit to a PM3 or PM4, but my use will mainly be for CrossFit and I don't necessarily need all the advanced features they offer.
My question pertains to the way my PM1 operates and whether it is normal or not. I have rowed on a newer model with the PM2 at my gym and it seemed normal and worked fine. My PM1 display seems to bounce around and it is hard to pick up what it is telling me. The numbers seem to change so fast I have trouble understanding the meaning behind the readouts. The pace and spm jump up and down continuously during the workout. I am curious if this is the way the old technology worked and I just need to adjust to it or if my used machine is so old that the monitor is not working properly.
Hope some long term rowers can remember back to the days when they used this equipment and offer some solutions.

Thank you-

PaulS · Post by **PaulS** » June 12th, 2007, 2:51 pm

The numbers should be as stable as any of the electronic PM's. "Jumpy" displays tend to be related to a failing sensor cable, batteries getting low, or perhaps even the monitor finally failing. (It's probably 20 years old by now).

For Cross Fit, you may not even really require a Monitor, just go as hard as you can for the prescribed time interval, but it is nice to have some idea of what is being accomplished.

johnlvs2run · Post by **johnlvs2run** » June 12th, 2007, 3:38 pm

Make sure the sensor is clean on the inside of the cage, and that it's plugged all the way into the monitor.

DragFactor · Post by **DragFactor** » June 12th, 2007, 4:42 pm

What the other two said.

I have a PM1 and a PM3 on a B. Both stable.

Steve.

wsucoug9 · Post by **wsucoug9** » June 13th, 2007, 12:26 am

Thanks for the replies. I cleaned off the sensor inside the fly wheel and it seemed to help somewhat. The strokes per minute readout is still all over the board, but I think I can live with that for a while. I initially plugged in new batteries, & double checked connections so it appears the remaining malfunction is due to age/use.
The distance, time, and total calories seem to be in working order, all the bare bones features I absolutely need for CrossFit.
This does seem to be extremely addicting, getting instant data to analyze based on effort put forth. Between this Concept 2 and my Nike+ I am very happy.

johnlvs2run · Post by **johnlvs2run** » June 13th, 2007, 1:02 pm

You can clean off the flat side of the fan well to make sure the surface is clear, and check the sensor line to see that it's in good shape.

I think you can take the pm1 apart and clean the terminals but am not sure about that.

c2jonw · Post by **c2jonw** » June 13th, 2007, 4:50 pm

Pace and spm should be stable and update once per stroke. Jumpy values usually mean either a failing sensor (less than $20 to replace), dirty sensor, dirty magnets (there are three of them imbedded in the flywheel), a bad magnet or possible a bad connection at the plug (pull the plug out and clean with alcohol). Also the spacing between the pickup and the flywheel is important- should be about 1/16-1/8" (1.5-3 mm). Also note that with the monitor acting this way it's unlikely the cumulative data is correct. C2JonW

DragFactor · Post by **DragFactor** » June 13th, 2007, 5:07 pm

Just to add that the socket for the plug from the sensor often develops dry joints on the circuit board within the PM1. The web site has instructions for disassembling the PM1 to clean the board, which cleans the LCD connectors too. I resoldered the 2.5mm jack skt conections at the same time. Bad connections here would produce the fault you describe, especially on the PM1 which doesn't calculate everything each stroke as later models do.

Steve.

davidsgift · Post by **davidsgift** » July 15th, 2007, 12:48 pm

If you would like a replacement pm1, I'd happily offer mine. I upgraded to a PM3 and now it's just sitting around. Is there anyplace to send an old PM1? I just hate throwing stuff away when it still works!