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Dave_whatever
Tinkerer
Username: Dave_whatever
Post Number: 1
Registered: 07-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, July 25, 2007 - 02:27 pm: | 
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Hello
I've recently aquired a nikon md-12 drive to go with my FE. It all seems to work fine except one part of its behaviour seems to be at odds to what i'd expect.
Namely, as soon as I turn the drive ON the camera's meter turns on and remains so until i turn the drive off again. What I understand is normal for the MD-12 is the meter turns on when the shutter release if half-depresed and stays on for about a minute. This doesn't happen.
I know the meter may stay on if a remote is connected to the front socket, bu I havent got one in and the plastic pin in the socket is sticking out, so i can rule-out that as the source of the problem.
I've taken the top-plate off and had a look at the wiring. The circuit board doesn't match exacly to any of the photos i've found online, which is not exactly surprising given they've been making them for 30 years. Anyway, I strongly suspect some previous owner has deliberatley shorted or soldered between some contacts to keep the meter on when the power is on. Its not a major issue for me but i'd prefer it to operate as it did when it left the factory. So, does anyone have any experience of this and know what might be shorted out, or know where I can get a wiring diagram to try and work it out myself? Thanks |
Krp
Tinkerer
Username: Krp
Post Number: 43
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, July 25, 2007 - 07:29 pm: |
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A couple of things come to mind. !st, you may have a MD-11 that has been labeled with a MD-12 name plate. The other is that one of the switches below the release button is stuck or shorted. There was a second switch added to allow the meter top turn off after the 16 second meter on cycle. The MD-11 was notorious for draining camera batteries because the meter always stayed on.
Put the top plate back on and peel back the leatherette below the release button assembly. You'll see the screws, 4 Phillips head hold the button assembly to the rest of the drive. There are only four or five wires running to the switches.
Good Luck, Kevin |
Dave_whatever
Tinkerer
Username: Dave_whatever
Post Number: 2
Registered: 07-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, July 26, 2007 - 12:48 am: |
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Cheers for the reply - yes its certainly badged as an MD-12, the serial number is 9xxxxx (off the top of my head) which aught to help identify it in some way. I'll have to have a look inside the release housing and see what I can find. Are MD-11s badged as MD-12s commonplace?
I suppose another way to check the model type would be to set it to single-shot and see if it winds the film on while the shutter is still depressed or only when I let go of it.
To be honest, i'm not too bothered which model it is since it only cost me a few quid (literally, we're talking single figures) but I'd rather know whether its a fault, modified behaviour of mislabled, for my own interest more than anything else! |
Dave_whatever
Tinkerer
Username: Dave_whatever
Post Number: 3
Registered: 07-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 30, 2007 - 02:59 pm: |
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Ok, i've taken the whole button section apart. It seems that some time in the past the drive has taken some damage to the button part (cracks etc visible on the outside, its probably been dropped onto a hard surface) which broke the metering microswitch away from the buton mechanism, which means its always "on", the button normalls hold the contacts apart. All i need to do to fix is epoxy it back into the cover making sure the microswitch contacs are held away from the other contacts when in the "dormant" position.
I've also sussed out why the drive always works in "continuous" mode even when set to Single - because of the damage, the top of the button housing was moved to one side slightly, meaing the S-C ring cam wasn't contacting the switch. This is easily rectified when i put the whole thing back together and make sure its seated correctly.
Cheers for the advice anyway. Incidentally does anyone know the best typeof glue to stick the leatherette back on with? |
Rlc
Tinkerer
Username: Rlc
Post Number: 14
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 30, 2007 - 04:36 pm: |
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Dave; Regarding sticking leather back, See Paul Ron's excellent advise, Restoration Page (July 28th) Richard. |
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