Performance Monitor Temperature Sensitivity?

[rakserv]

hello,
i recently experienced some intermittent operation with a PM2. after it had been left outside all night, temperature down in the 40s F it would not turn on (screen dead), the batteries were replaced with new cells and it sill would not turn on. after driving around with in the car (temperatures 80s F) it powered on successfully.

the only quantifiable variables seem to be time and temperature, other than it's electronics any ideas ?
thank you,
-rob

[Allan Olesen]

Let me guess: It was outside in the cold, you took it into a heated room and after some time tried to turn it on?

Electronics really don't like that. The air in the heated room contains much more humidity and it will condense on the cold surfaces, also the surfaces of the circuit board inside the monitor.

So you have probably had some currents creeping through the moisture on the board, causing the electronics to not work. Later, when the monitor got to room temperature, the condensed water has evaporated, and the electronics have started working again.

If this is the case, you were lucky. Sometimes you can fry the electronics for good by doing this.

[Carl Watts]

There is a specific component in the PM2 that provides the negative 3V for the LCD to function.

This part fails quite often and after all the PM2 is at least 20 years old.Most of the time this parts fails totally and you get no display at all.

I have repaired one that was temperature sensitive and then I tested the PM2 by leaving the monitor in the freezer and it still powered up.

There are probably numerous PM's out there with this fault but there are not too many people who like to row in sub Zero temperatures

[rakserv]

Let me guess: It was outside in the cold, you took it into a heated room and after some time tried to turn it on?

Electronics really don't like that. The air in the heated room contains much more humidity and it will condense on the cold surfaces, also the surfaces of the circuit board inside the monitor.

So you have probably had some currents creeping through the moisture on the board, causing the electronics to not work. Later, when the monitor got to room temperature, the condensed water has evaporated, and the electronics have started working again.

actually, that was not the sequence ... it was stored outside at a gym overnight because it was being worked on ... in the morning when it was still outside on the deck it would no power on. the monitor was removed from the erg to take home and after it had been in the car all day, it powered on successfully.

but yes, electronics can be very touchy

[rakserv]

There is a specific component in the PM2 that provides the negative 3V for the LCD to function.

This part fails quite often and after all the PM2 is at least 20 years old.Most of the time this parts fails totally and you get no display at all.

I have repaired one that was temperature sensitive and then I tested the PM2 by leaving the monitor in the freezer and it still powered up.

There are probably numerous PM's out there with this fault but there are not too many people who like to row in sub Zero temperatures

thanks carl!

[rakserv]

Same Topic Different Situation:
Location: Southern California, Normal Weather Warm (mid-50Fs to 60F lows) and Dry
Current Weather: Lower Than Normal Temperatures (high 30Fs/Low 40Fs) and Damp (unusual amount of rain and humidity)

Local Crossfit Gym with a Fleet of 10 Model Cs with PM2/PM2+ Performance Monitors
Conditions Inside the Gym:
No Environmental Controls (No Heating or Cooling) and lots of rollup doors

Suddenly, multiple PM2/PM2+s failed to turn on (LCD):
1. (3 of 10) either by the ON/OFF button or pulling the handle
2. (2 of 10) ON/OFF button stopped working, but pulling the handle turned on LCD

after replacing the 3 of 10 that failed to turn on the LCD at all with other working PM2/PM2+s, i took the old monitors to my house where the temperature inside is mid to high 60Fs and low humidity . After 12+ hours, all three turned on with the ON/OFF switch.

This temperamental temperature/humidity situation doesn't really work for the crossfit gym, but the PM2/PM2+s will work just in a more environmentally friendly situation.

Any thoughts on a remedy for this? Carl do you think that the -3V voltage regulator could be the culprit?