*ist D frozen

My old istD (given to a relative) has developed a fault. The camera appears to work OK (metering, autofocus, etc.) but when the shutter is fired, the mirror lifts but the shutter doesn't operate. The main batteries are OK but the backup battery (lithium cell) has never been changed and the camera is over 5 years old (it still registers 3V on a voltmeter but I can't test the current delivery). Before I venture out to try and find a replacement, does anyone know if the failure of this battery can knock out the shutter operation, since it is related to timing, i.e. the clock setting?

John

As far as I understand the button cell is just there to maintain menu/clock settings it should have no effect on the operation of the camera.

Does the mirror remain locked until you remove the main batteries?

Agreed. The button cell would not have the power to move the mirror.

3V is a bit low for a lithium cell. 3.3-3.7V would be nearer.

I would suggest:
* Remove the back up battery and the main batteries
* Leave for an hour or two
* Put in a new back up battery
* Put back in the main batteries
* Reset the camera to defaults in the menu

HTH!
Matt

You forgot the all important one Matt....


....cross your fingers

I Hope Matts suggestion works John, the istD is a nice camera, I gave mine to a relative too (my son) and I miss it already

Following a call to Pentax who were unable to help, except to say send the camera back to them for repair, I tried reloading the firmware, after which the camera started to perform correctly again. However, during a photo session, the user accidentally pressed the flash button on the top plate when the camera went into the frozen shutter mode again. Since the flash appeared to have been involved in the earlier incident, I suggested firing a flash shot off, which she did, and the shutter worked again. I assume that the camera was waiting for some sort of flash complete message before completing the exposure but could not get it because the flash was not raised. However, pressing the flash button again did not cause the fault to recur, so something is amiss.