On Thu, 30 Dec 2010 17:02:27 +0000 (UTC), Meat Plow
wrote:

On Thu, 30 Dec 2010 08:48:48 -0800, wrote:

Sorry if this type of problem has been discussed before, I didn't find
any useful usenet search of this newsgroup history. Boy, do I miss
DejaNews! If someone knows of a usable search of
sci.electronics.repair please post it. The google one was pretty
terrible IMHO.

I have a "computer" on a Schwinn exercise bike that the monochrome LCD
is nearly blank. I can see that it is working, but the display is very
light. When I turn it on I can hear the friction control motor in the
bottom of the bike working. That system does seem to work, I can
increase the friction with the buttons on the computer. So buttons
work, display works a little, other functions work.

A single failure in the display circuitry. The problem is just the
display.

This runs on 4 C cell batteries, I did check the voltage on the
batteries and when I press the soft "start" button on the panel the
battery voltage diminishes from over 6V to less than 1V. Something is
dragging it down!


What should I be looking into?

If something is dragging the voltage at the batteries down 5 volts that's
going to consume a huge amount of current seeing it's almost a short
circuit. I doubt any of the internals would be able to sustain such a
current draw without making a little smoke. I'd check for a bad
connection within the battery cage itself. Maybe where the contacts are
riveted to a supporting structure. This makes more sense to me.

Yes, except for the problem didn't occur until I pressed the start
button on the panel. a soft button, btw. That kind of leaves out a
constant short from the battery box.