Pentax Motor Drive A

pendennis · 11-15-2017, 01:56 PM

I'm running into a problem with a couple of Pentax Motor Drive A units. One I bought a couple of months back included with a Program Plus, and the second, which arrived today. Both units are in what I'd call excellent condition. I mounted one on another Program Plus, and the one arriving today on a Super Program. According to all literature, the drive should be compatible with both model cameras.

The problem is with the film advance. On either camera, with either drive attached, I can cock the shutter manually, and the shutter can be fired from the camera, or the drive and in either the "S", "H", or "L" mode. It doesn't make any difference the setting on the camera, either Program, Manual, or 100/125 default. The drive and advance are aligned, and the drive fits snugly on both cameras. The vertical release will not trip the shutter at all. The motor will not come on, turning the film advance gears.

I have tried new batteries in each tray, swapped trays, and repeatedly mounted and dismounted the drives.

I've read the instructions completely, and checked both camera's user manuals.

Any ideas? Thanks!

jimfellows · 11-16-2017, 06:22 AM

I just want to clarify your what exactly the issues your are having with the drive. The film will not advance at all. or only when firing in the vertical shutter release button? The vertical shutter release button does activate the shutter.

It has been a while since I had my Super program and Motor Drive A, but I do remember the vertical button being a bit finicky. Dose the motor on drives work when off the cameras, do they make noise like the motor is working when on the cameras? With the drives off the cameras, does the dick on the camera where the drove attaches move when you manually advance the shutter on the camera?

Jim Fellows

pendennis · 11-16-2017, 08:05 AM

The vertical release doesn't function at all. The drive doesn't make any noise as though it's trying to operate. Both cameras and drives had the film counter advanced to "1" before testing the drives. The LED's do not activate.

After sleeping on the problem, I'm wondering if the cameras being empty have an effect. These were all "dry" tests, i.e. no film in the camera. I didn't want to waste film testing these drives. I don't see anything in the instructions as to dry firing.

Ontarian50 · 11-16-2017, 09:23 AM

With vintage motor drives (and flash units), the number one cause of trouble is bad battery contacts.

Often the devices were stored with old leaking batteries in them for months or years. Cleaning the contacts thoroughly often helps, although it can be hard to reach the ones deep inside a motor drive battery compartment.

If the batteries leaked badly, then the corrosion spreads to surrounding wires and circuitry, making repairs much more difficult, if worthwhile at all.

Shine a light down inside the battery compartment, and maybe you can see the cause of your troubles. If all is pristine, then the problem is more serious.

pendennis · 11-16-2017, 12:49 PM

Originally posted by Ontarian50

With vintage motor drives (and flash units), the number one cause of trouble is bad battery contacts.

Often the devices were stored with old leaking batteries in them for months or years. Cleaning the contacts thoroughly often helps, although it can be hard to reach the ones deep inside a motor drive battery compartment.

If the batteries leaked badly, then the corrosion spreads to surrounding wires and circuitry, making repairs much more difficult, if worthwhile at all.

Shine a light down inside the battery compartment, and maybe you can see the cause of your troubles. If all is pristine, then the problem is more serious.

The battery contacts have been inspected and thoroughly cleaned, even though there were no signs of battery leaks, or age-type corrosion. The positive and negative contacts in the battery trays are the actual battery contacts.

Thanks for the response.

**c.perkins** · 11-16-2017, 05:23 PM

You do have the vertical shutter release switch lever moved to the position so the red square is showing ?
Green square showing is safe position = will not activate.
Just some thoughts.
My motor drive A does not function off the camera.
Installed it and with out film dry fired it, all worked fine.
Vertical shutter release is like a safety on a rifle, green is safe(no trigger), red is fire(will trigger).

Clarence

11-15-2017, 01:56 PM	#1
pendennis Junior Member Join Date: Aug 2017 Posts: 41	Pentax Motor Drive A I'm running into a problem with a couple of Pentax Motor Drive A units. One I bought a couple of months back included with a Program Plus, and the second, which arrived today. Both units are in what I'd call excellent condition. I mounted one on another Program Plus, and the one arriving today on a Super Program. According to all literature, the drive should be compatible with both model cameras. The problem is with the film advance. On either camera, with either drive attached, I can cock the shutter manually, and the shutter can be fired from the camera, or the drive and in either the "S", "H", or "L" mode. It doesn't make any difference the setting on the camera, either Program, Manual, or 100/125 default. The drive and advance are aligned, and the drive fits snugly on both cameras. The vertical release will not trip the shutter at all. The motor will not come on, turning the film advance gears. I have tried new batteries in each tray, swapped trays, and repeatedly mounted and dismounted the drives. I've read the instructions completely, and checked both camera's user manuals. Any ideas? Thanks!

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11-16-2017, 06:22 AM	#2
jimfellows Senior Member Join Date: Aug 2014 Location: New Hampshire Posts: 108	I just want to clarify your what exactly the issues your are having with the drive. The film will not advance at all. or only when firing in the vertical shutter release button? The vertical shutter release button does activate the shutter. It has been a while since I had my Super program and Motor Drive A, but I do remember the vertical button being a bit finicky. Dose the motor on drives work when off the cameras, do they make noise like the motor is working when on the cameras? With the drives off the cameras, does the dick on the camera where the drove attaches move when you manually advance the shutter on the camera? Jim Fellows

11-16-2017, 08:05 AM	#3
pendennis Junior Member Join Date: Aug 2017 Posts: 41 Original Poster	The vertical release doesn't function at all. The drive doesn't make any noise as though it's trying to operate. Both cameras and drives had the film counter advanced to "1" before testing the drives. The LED's do not activate. After sleeping on the problem, I'm wondering if the cameras being empty have an effect. These were all "dry" tests, i.e. no film in the camera. I didn't want to waste film testing these drives. I don't see anything in the instructions as to dry firing.

11-16-2017, 09:23 AM	#4
Ontarian50 Veteran Member Join Date: Mar 2015 Posts: 530	With vintage motor drives (and flash units), the number one cause of trouble is bad battery contacts. Often the devices were stored with old leaking batteries in them for months or years. Cleaning the contacts thoroughly often helps, although it can be hard to reach the ones deep inside a motor drive battery compartment. If the batteries leaked badly, then the corrosion spreads to surrounding wires and circuitry, making repairs much more difficult, if worthwhile at all. Shine a light down inside the battery compartment, and maybe you can see the cause of your troubles. If all is pristine, then the problem is more serious.

11-16-2017, 12:49 PM	#5
pendennis Junior Member Join Date: Aug 2017 Posts: 41 Original Poster	Originally posted by Ontarian50 With vintage motor drives (and flash units), the number one cause of trouble is bad battery contacts. Often the devices were stored with old leaking batteries in them for months or years. Cleaning the contacts thoroughly often helps, although it can be hard to reach the ones deep inside a motor drive battery compartment. If the batteries leaked badly, then the corrosion spreads to surrounding wires and circuitry, making repairs much more difficult, if worthwhile at all. Shine a light down inside the battery compartment, and maybe you can see the cause of your troubles. If all is pristine, then the problem is more serious. The battery contacts have been inspected and thoroughly cleaned, even though there were no signs of battery leaks, or age-type corrosion. The positive and negative contacts in the battery trays are the actual battery contacts. Thanks for the response.

11-16-2017, 05:23 PM	#6
c.perkins Loyal Site Supporter Join Date: Jun 2017 Location: New Lisbon, WI. Photos: Gallery \| Albums Posts: 515	You do have the vertical shutter release switch lever moved to the position so the red square is showing ? Green square showing is safe position = will not activate. Just some thoughts. My motor drive A does not function off the camera. Installed it and with out film dry fired it, all worked fine. Vertical shutter release is like a safety on a rifle, green is safe(no trigger), red is fire(will trigger). Clarence