Pentax ME Super Repair

The ME and ME Super represent Pentax's effort to create smaller, easier to handle SLRs compared to previous generations. They were introduced alongside the Pentax MX, a compact all mechanical SLR, and a series of redesigned compact lenses, the Pentax-M lenses. The ME Super has an electronically timed shutter, which enables an aperture priority autoexposure mode. While the light meter and various shutter speeds require electricity to function, the fundamental functions of the camera are still primarily mechanical. For example, the mirror and shutter release, self-timer, film advance and focusing are all fully mechanical. The camera can even shoot at its default shutter speed, 1/125 of a second, without batteries, serving as a kind of fail safe mode.

The ME Super has a modular construction, which makes it quite easy to disassemble, compared to other SLRs of its era. Separating the front lens board and mirror box from the main chassis is usually the first step in a major repair or overhaul. From there, individual subassemblies can be separated and inspected. If the viewfinder is dirty, that can be removed, disassembled and cleaned. If the shutter is malfunctioning, it can be removed as a unit and either serviced or replaced.

All ME Supers share the same overall construction, but there are some differences between production runs. The main PCB and particularly the adjustment potentiometers vary from year to year. Some of the wired connections may also look different than what is presented in the guides. Before unsoldering anything, make sure that your camera matches what is shown, and if it differs, take your own pictures to reference during reassembly.

The most common failures for the Pentax ME Super are a stuck reflex mirror or an advance lever that winds continuously (aka, "infinite wind"). Both have the same root cause, which are degraded rubber dampers in the mirror box mechanism. The failure can usually be repaired by cleaning out the old material to free up stuck parts (see the Mirror Box Disassembly guide).

Stuck shutter curtains are another common failure and are also caused by degrading rubber components. Disassembling and cleaning the shutter can restore proper functionality (see the Shutter Block Disassembly guide).

The electronics in the ME Super are generally reliable, but it's not uncommon to see inoperable light meters. This is usually caused by corroded battery contacts or internal wiring, which is repairable. Sometimes the light meter cell can fail, which requires a replacement part.

If you are already performing significant disassembly of the camera for a repair, consider doing a more complete overhaul of the camera to reduce the chance of future issues. The following service will address the most common failure points of the ME Super.

• Mirror box mechanism: Remove old degraded rubber bumpers and clean all affected components.
• Shutter block: Remove old degraded rubber bumpers and clean curtain pivots.
• Viewfinder: Clean and replace old foam light/dust seals.
• Light seals: Remove and replace old foam light/dust seals.

In general, cameras do not require lubrication to function. They should be able to operate normally without oil or grease. Consequently, if a camera is not functioning, adding lubrication is not the solution. But there are some areas where adding proper lubrication will improve performance or reduce wear. Whenever possible, use the service manual for your specific camera model to identify critical points. When that isn't available, some general guidelines can be used to determine what kind of lubrication a mechanism might benefit from.

Generic levers and gears: No lubrication. Most of the mechanisms in a camera shouldn't be lubricated. A latch moving back and forth or an idler gear spinning do not require lubrication. If such a mechanism is sticking, it needs to be disassembled and cleaned. Lubrication is not free and comes with drawbacks, mainly that it attracts dirt and grime. If an interface is lubricated, it needs regular cleaning and re-lubrication to maintain. So the first rule is, unless it's serves a specific purpose, don't use lubrication.

Fast moving shutter mechanisms: A lightweight synthetic oil (e.g. NyOil). These are gears and shafts that spin or move rapidly when the shutter is fired. Some cameras require oiling the interfaces to get more consistent shutter speeds, but the shutter in the ME Super runs dry, without any lubrication. When servicing the shutter, cleaning and reassembly is all that is required.

Latching points: A heavy weight lithium grease with molybdenum disulfide (NLGI 3-4). There are a lot of metal-to-metal interfaces where mechanisms interact with each other. Sliding, hooking, latching, etc. These are often high friction interfaces and if left unlubricated can wear over time. Choose a grease that is very sticky and will stay in place on the applied surfaces. The moly additive helps further reduce wear at the surface of the materials.

High load interfaces: A medium weight lithium grease with molybdenum disulfide (NLGI 2-3). The film advance mechanism would fit into this category where it's common practice to grease the shaft of main wind gear, providing a much smoother feel and, more importantly, preventing wear.

Knob and dial detents: A medium weight lithium grease (NLGI 1-3). Shutter speed dials, aperture rings, etc. Most of the time the clicks will be provided by some kind of spring loaded feature jumping between grooves. Picking the best lubrication for these interfaces can require some trial and error as getting the proper feel is highly dependent on the geometry of the detents, the force of the spring, and the types of interfacing materials.

• Open cell foam, self-adhesive, 1.5 mm thick: For light seals and mirror bumpers
• Isopropyl alcohol: General cleaning
• Cotton buds: General cleaning
• Contact cement: Adhesive for attaching leatherette
• Molybdenum grease: Lubrication for mechanical latching points

See the Pentax ME Super Troubleshooting page.