Checking a Minox A or B is very easy and can be done in a few minutes without tools. You can easily do this before purchasing. However, the prerequisite is that you have the camera in your hands. Even if you want to buy the camera online and a certain feature is important to you, you can ask the seller to carry out the corresponding test. It is so quick and easy that there should be no excuse for a reputable seller to carry out the test.
All tests presented here can be carried out directly for Minox A IIIs, B and AX. For the LX and EC models you need a suitable battery for the shutter test and the battery check of course. With the BL you only need a battery to test the light meter.
Check the seals
The first question that arises is whether someone has ever disassembled the camera to try to repair it. Although this is not a problem in principle, it often results in more damage than repair. If the seller can say why and, above all, by whom the Minox was repaired and can show proof, this shouldn’t be a problem.
A camera in original factory condition can be easily recognized by the seals that cover three screws. If a seal is missing, the camera has probably already been disassembled. The check takes place in two steps.
Open the film chamber as if you were loading a film cartridge. Look at the small set screw shown in the picture below. The screw head must be covered with black paint. Left: Seal renewed after a professional repair. Right: Removed seal
Look at the two screws that hold the cap in place. The top of the cap with the two screws is easy to control as long as the film chamber cover is pulled out. Here too, the heads of the two fastening screws must be covered with black paint. Left: Original Minox seal. Right: Removed seal
Please note that the screws on the Minox AX are not sealed at the factory. You can only check whether the screw slots are intact.
Check the shutter
Set the speed dial to maximum speed
Shutter cocked
Close and open the camera and look at the lens from the outside. A circle must be visible on the metal surface of the shutter blade. This signals that the shutter is cocked and the shutter blades are in the correct position. If the circle is not visible, there is probably a problem with the shutter blades.
Press the shutter release button. You should hear a short click and the indicator circle will disappear. The lens should again be closed by a continuous metal surface that does not show a circle. In this case the closure is fine. Shutter blades defectiveIf you can’t hear anything or don’t see a consistent, continuous metal surface without a circle before the lens, there’s something wrong with the shutter blades.
Repeat the last 3 points for all shutter speeds. Pay attention to whether the clicking sound lasts longer and whether you can see the lens during the longer exposure times. Check whether the exposure time for 1/2 second is plausible. On a separate page we see how to measure the speeds exactly with an additional tool.
Check viewfinder
Open the camera, look through the viewfinder and aim it at the sky or a bright surface. Check whether the viewfinder image is clean, without scratches, spots or cloudiness. Also pay attention to the area outside the light frame.
Check the lens
Set the speed dial to “T” (for Minox LX, set the shutter midway between 2000 and A; for Minox AX set to “B”). Close and open the camera. Press the release button to open the shutter. The shutter stays open as you release the button (not for the Minox AX; here you have to hold down the release button). Now you can inspect the lens and the lens window. They must be clean, without scratches and fungus.
Turn the distance dial and watch closely to see if the lens rotates. This is hard to see, maybe you need an extra lamp to see it. If the lens does not move, the transmission between the distance dial and the lens is disengaged. In the following video you can see the lens while the distance dial is turned. Watch the edge of the lens to see how it rotates. Also observe how the lens shifts from front to back:
Check film advance mechanism
Open the Minox and turn it on its back. Open the film chamber. Push the camera back by holding two ends of the opened camera, without touching the opened cover, push the camera together; the three prong film advance spindle should rotate clock wise,otherwise the film advance mechanisam is faulty. In the following video you can see how the spindle rotates correctly:
Note that this test only tests the basic feed rate, not the uniform spacing of the negatives. More information here.
Check the exposure counter
This function is independent of the film advance mechanism and must therefore be checked additionally. It may happen that the exposure counter does not work at all or does not work reliably. I had this happen with two Minox A’s that had been improperly repaired. On one camera the counter didn’t run at all and on the other the counter sometimes stopped moving. So if the camera seals have been removed, you should pay special attention.
The easiest way is to carry out this check during the shutter test. To do this, pay attention during cocking to see whether the counting disc moves by one mark.
Check the parallax compensation
Be sure to check the parallax compensation. With the camera open and the viewfinder facing you (you are looking at the front of the camera), turn the distance dial. You should notice the viewfinder moving sideways. If not, the linkage between the distance wheel and the viewfinder is defective.
In the following video you can see when turning the distance dial the viewfinder’s optics swivel to show the right frame, especially in close-ups:
Check the measuring chain
3 Minox measuring chains. On the far right a self-made one
There are three types of Minox chains : unbeaded chain for EC, metric measuring chain in meter and imperial measuring chain in feet.
The bead positions on imperial chains are 8″ (20cm), 10″ (25cm), 12″ (30cm) and 18″ (46cm). The total length of the chain is 24″ (61cm).
The bead positions on metric chains are 20cm, 24cm, 30cm and 40cm. The total length of the chain is 60cm.
For an intact metric chain, dimension L4 in the picture below must be 40cm. For an imperial chain, L4 must be 18″ (46 cm).
Minox metric chain
Be careful to match a metric chain to a metric camera, and an imperial measuring chain to an imperial camera. You can differentiate a metric chain easily from an imperial chain: the first three beads on metric chains are separated by unequal distances, the first three beads on imperial chain are separated by equal distances. The 8″ bead on imperial chain is exact match for 20cm bead on metric chain.
Check the chain against a ruler. The chains can wear out. I measured deviations of 1cm at length L4.
Check battery (BL, LX, EC)
Minox BL: According to the original operating instructions, one Mallory PX675 is required. Since this is no longer available, I use a hearing aid 675 button cell. Battery check: With the camera open, press the slider for the ND filter up. The pointer on the exposure meter must move to the right edge.
Minox LX: According to the original operating instructions, one Mallory PX27 is required. Since this is no longer available, I use 4 x LR43 button cells with adapter Check the battery with the camera closed or opened and cocked. Press the lever on the shutter speed dial towards the front of the camera; the green light should light up.
Minox EC: Battery: Same as Minox LX, see above. Battery check: Open the camera, press and hold the slide switch to the battery symbol. Look through the viewfinder, the red LED should light up.
Check the light meter (B, BL)
The pointer of the instrument must deflect when the front of the camera is held in bright light. However, this is not proof that the light meter works accurately. In sunlight or a very bright lamp, the pointer must move completely to the end of the scale. If not, the exposure meter is no longer OK. The exposure meters cannot be repaired, but they can be completely replaced on the Minox B.
Check the accuracy of the exposure meter with an external, tested exposure meter or with one of the numerous smartphone apps.
Open the camera, look through the viewfinder and aim it at the sky or a bright surface. Check whether the viewfinder image is clean, without scratches, spots or cloudiness. Also pay attention to the area outside the light frame.
Set the speed dial to “T” (for Minox LX, set the shutter midway between 2000 and A; for Minox AX set to “B”). Close and open the camera. Press the release button to open the shutter. The shutter stays open as you release the button (not for the Minox AX; here you have to hold down the release button). Now you can inspect the lens and the lens window. They must be clean, without scratches and fungus.
Open the Minox and turn it on its back. Open the film chamber. Push the camera back by holding two ends of the opened camera, without touching the opened cover, push the camera together; the three prong film advance spindle should rotate clock wise,otherwise the film advance mechanisam is faulty. In the following video you can see how the spindle rotates correctly:
This function is independent of the film advance mechanism and must therefore be checked additionally. It may happen that the exposure counter does not work at all or does not work reliably. I had this happen with two Minox A’s that had been improperly repaired. On one camera the counter didn’t run at all and on the other the counter sometimes stopped moving. So if the camera seals have been removed, you should pay special attention.
Be sure to check the parallax compensation. With the camera open and the viewfinder facing you (you are looking at the front of the camera), turn the distance dial. You should notice the viewfinder moving sideways. If not, the linkage between the distance wheel and the viewfinder is defective. 
