Need help in Mamiya DTL 1000 meter calibration.

The meter seems to work in the spot mode. If I place in average mode the meter need goes to the + or overexposed reading. I removed the top to see if the meter linkage chain was off. I found that my spot metering was also not working at speeds below 1/250. I noticed moving the meter chain affected the range for the meter. I can't adjust the chain but is there a way to adjust the meter unit itself? The unit has a red painted slotted screw on the side. I don't know if this is an adjustment, does anyone have any info that can help me? TIA.

This is a LONG shot. but I vaguely remember there being a adjustment-screw where the chain meets the front of the prism (of course, under the cover). - David Lyga

David Lyga said:

This is a LONG shot. but I vaguely remember there being a adjustment-screw where the chain meets the front of the prism (of course, under the cover). - David Lyga

Click to expand...

I looked and the chain near the front of the prism runs down to the A/S switch. The chain is used to transmit pulling the little pointer in the viewfinder, quite ingenious. The meter chain wraps around a large silver housing where the meter and needle resides. The whole housing unit rotates when the asa or the shutter speed dial is turned. When the meter housing rotates that determines the needle exposure. I have properly set my asa to 84 and speed to 1/4 to position the chain. However the meter thinks that is too much light when I set the asa and speed to the proper exposure according to my other DTL with a working meter. The meter cutoff is definitely being triggered at the wrong Asa and shutter speeds! It seems the meter is probably 4 stops too fast. If I compensate I run out of available stops. What's strange is the meter was working perfectly and was accurate last week. The meter was always a little slow to react but when it got going it was good. Then I tried it again the next day and the meter needle shot to the + mark and stayed there no matter the combination. These things are very old and I guess mine just ran its course and died. The shutter works and sounds good and I cleaned the prism and viewfinder since I had the top off so not all is lost!

Look VERY closely and carefully where the chain is near the prism. Use a magnifying glass. I still remember there being a screw that adjusts this. - David Lyga