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Dave
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 28, 2004 - 10:52 am: | 
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I recently picked up a pentax spotmatic at an antique shop, and the meter was still dead even after replacing the battery. I cleaned the battery compartment, and the various contacts on the bottom of the camera, still didn't work. Then I took the top off, and found that I had 1.5 volts everywhere that seemed appropriate, the one irregularity is that the switch for the meter never seems to turn off. there is voltage in the lightmeter circuit no matter what position it is in. So could this be related to my problem, do I need new sensors, or a galvanometer, and if so, is there somewhere I can get replacements.
Thanks
Dave |
Berk Sirman
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 28, 2004 - 11:44 am: |
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I do not know enough about repairing cameras to answer whether you need a galvanometer or not but with a camera of this age the CDS cell may be shot and even not it may be not linear. If you have put the effort and taken the top plate off and possibly changing the galvanometer it is a good idea to change the cell too. I do not know the details to do this.
Once I got a CdS cell from Mark Hama (www.markhama.com) for a Yashica camera that was at repair. Maybe he has cells that fit spotmatics too. The CdS cells are, I think, pretty standard anyway for TTL cameras that have them in the viewfinder so even if it is not an exact replacement I think it will work.
From what I have heard the switch mechanism in spotmatics are pretty fragile so maybe that is damaged. |
Aaron
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 28, 2004 - 07:43 pm: |
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What battery are your using? Make sure the baseplate should be "-ve". If you use a substitute instead of the the original mercury cell, it is likely you have put the battery the other way round. Aaron |
Stuart Willis
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 31, 2004 - 07:04 am: |
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For whatever it is worth.
The Spotmatic uses two CDS cells wired in parallel. If therefore one of them has gone short circuit - then the total array is then short circuit. Since the Spotmatic will work just fine on one cell - it is perfectly feasible to just totally isolate the bad one.
If you are using the correct battery for the camera then it would be a mercury cell of 1.3v.
The spotmatic will however work perfectly on a Silver Oxide 1.5v cell of the same physical package.
Also - it is conceiveable that the hot wire from battery compartment to the first soldered connection on the electronics, has black wire corrosion (cores corroded to a non conductive and non-solderable black powder) This is typical of aged cameras which use mercury cells. In such instance you will need to replace the wire.
Hope this helps
Stuart Willis |
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