|Re: 41CV Math Pack Power Problems|
Message #4 Posted by Dan Grelinger on 16 Sept 2008, 11:46 a.m.,
in response to message #3 by Peter Woysch
That is strange behavior, that if you wait more than 10 minutes after turning if off, it is able to turn back on again. About the only thing I can suggest is trying new batteries. This type of problem may be related to an interaction with the batteries and the small extra power requirements for the module. A bit of a stretch, but if the batteries are marginal, the extra time in an off state may allow enough voltage recovery to allow a turnon. If the module is not there, a somewhat smaller amount of power is required, perhaps letting the HP-41 turn on. One would expect the BAT annunciator to be turning on, though.
Another guess might be that the math pac has a marginal thermal problem, i.e. when it has been used (and theoretically slightly warmer due to power dissapated from use) it has a failure that locks up the HP-41 when it is polled at turn on. This will prevent it from essentially turning on. If it has not been on for awhile, it cools down, and function is restored. You may try putting it in the fridge for awhile, turning it on, then off, then back on again. If it starts off cold, it would take awhile to heat back up, and you could rule in or out a circuit thermal issue.