A very puzzling power problem...

[unixronin]

...upon which I solicit the wisdom of the clueful among my readership.

I have on the desk in front of me an Olympus D-500L digital camera.  I bought it in about 1997, with a set of four Olympus-branded 1.2v (remember that, it will be significant later) NiMH AA batteries and an Olympus-branded NiMH battery charger.  For the past nine years it's worked perfectly with successive sets of 1.2v NiMH batteries of progressively increasing capacity (the original Olympus batteries were 1300mAh, which got progressively replaced with 1600mAh, 1850mAh, 2100mAh, and now 2300mAh NiMH batteries).  About a week ago, it very abruptly totally stopped powering up with NiMH batteries ... but still works perfectly with 1.5v alkaline or photo-lithium batteries.

Olympus has been unable to solve the problem, or suggest any cause, over the phone.  "Your mission, should you choose to accept it":  if anyone has any insights on this, here's your chance to reveal the might of your all-dominating consumer-electronics fu.  Otherwise, the only recourse is to send the camera in to Olympus for diagnosis and repair.

Comments

[greyman.livejournal.com]

Clean the contacts. It's just barely possible that the voltage drop caused by corrosion on the contacts would be enough to dump the 1.2v below the threshold, but not the 1.5v batteries.

Check the spring tension of the contacts for similar reasons.

If that doesn't help, I suspect change in the value of an internal component (voltage divider resistor, perhaps). Capacitors and resistors do change over time.

[otherbill.livejournal.com]

D'oh, you beat me to it! Dirty contacts and contact spring tension was the first thing that came to mind.

[unixronin.livejournal.com]

Clean the contacts. It's just barely possible that the voltage drop caused by corrosion on the contacts would be enough to dump the 1.2v below the threshold, but not the 1.5v batteries.
Check the spring tension of the contacts for similar reasons.

Both good thoughts, but I've already checked those. There's no visible corrosion on the terminals, and the contact springs are still good -- it actually requires a couple of pounds of force to close the hinged battery-compartment door with batteries in place.

I suspect your second specilation, some internal component drifted or leaked, is closer to the mark. It's even possible that lubricant on some key internal component cycled at power-on (the lens zoom, perhaps) has thickened with age to the point that it loads a motor enough to pull the voltage down past a critical threshold value and prevents the logic board from booting up.

[greyman.livejournal.com]

It runs a motor on bootup? That's a strong possibility then. It's old enough for a clean'n'lube anyway.

[unixronin.livejournal.com]

Yup, a couple of things buzz and whir internally as it powers up. I think it makes sure the lens is fully zoomed in, and cycles the mirror (unlike many later digicams, including my Canon, it's a true digital SLR with a TTL optical viewfinder).