MetroLux is getting pretty old. I made the first one in about 1983. Hand wired. MetroLux has proven to be a robust design. I receive very few inquiries for repair, but recently I have had two. Both I fixed by email: a 'socially distanced' repair.
Both units were MetroLux IIs. They had completely different symptoms. If your MetroLux II is doing something weird, then you probably need a RESET. This is very simple, but the instructions are in that lost instruction manual. I can't even find mine.
Here's what you do. First, write down your calibration numbers. There are two of them. These can be seen by pressing/holding the SETUP button. Locations #1 and #2. Write those down.
Next, turn off MetroLux. Then, while holding the SETUP button down, turn on MetroLux and release the button. I believe "1.1" will appear as the 'time' on the display. Now push the "START" or "EXPOSE" button (Same button, different names depending on the when your unit was manufactured.)
The memory has now been cleared and reset. Reload the CAL numbers and test again.
If this doesn't work, it can be that your hardware is broken.
I'm still repairing both MetroLux Ones and IIs. Minimum cost is $50 plus return shipping. All repairs to date have been the minimum.
POCKETSPOT REPAIR
I had never repaired a PocketSpot until a couple of months ago I fixed one that was 10 years old. Repair charges for PocketSpot are the same as for MetroLux: $50 minimum + return shipping + parts and labor. Most parts are in stock. There is no reset for a light meter.
If you contact me by email, I will try to do what I can to avoid you shipping the meter here. As I have only repaired one unit, I can't give you any history except it was relatively easy to fix and costs were held to the minimum.
Feel free to contact me with questions. Put METROLUX or POCKETSPOT in the title.
ejwoodbury at gmail dot com