    
Mikesnothome
Tinkerer
Username: Mikesnothome
Post Number: 1
Registered: 02-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 25, 2012 - 06:25 pm: | 
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I have recently acquired a canon a-1 which seems to be in fair condition with some casual external wear.
However while in program mode, the light meter read-out gives the maximum exposure of the given asa dial value regardless of lighting conditions. I've done some research and have experience with electronic hardware repair so I found a service manual and opened it up.
I could not identify loose connections or corrosion. I did find that the photocell had a white crystalized film covering it which I scrapped off. I do not have any camera specific test equipment for measuring the output of the photocell, and I've never worked with cameras before so I closed it back up.
There was no performance change with the photocell being cleaned up, but for one brief moment a day later the meter seemed to give actual variable readings when initially turned on, but quickly went back to giving a constant max exposure reading.
For your reference the max read-out while at asa 100 in full program mode has been "15" 1.8" with a FD 50mm 1:1.8 lens. This is the readout regardless of full day sun light or dim room light etc. Also I have a currently available energizer 6v battery inside.
That short instance of actual variable readouts leaves me baffled, does anyone have any thoughts on this? Also what kind of tester is required to test the bus leads for the photocell? can this be achieved with a standard circuit testing meter? |
