Otherwise you will do more harm than good....
A few intro shots....
Two "Mighty 19's.... And here is a Zenit-12. Yes it is smaller than the 19.
Another difference with the "normal" Zenits is the esquisite leather ever ready case. No stiff leather here. Next to the 19 (text is now restored but not in this shot) is it's brother the 18. Almost the same but no depth of field preview button. And it has an aperture priority program built in. Usuable with all lenses if stopped down but with the original and rare Zenitar stopping down the lens isn't nessecary.
The Zenit-19 or the "Mighty" 19 as I like to call it, is one of the best FSU cameras around. It has enough speeds and is a delight to work with. But the innards of the 19 are a delight as wel. In sharp contrast with other Zenits the 19 has a modular built. It has an electronics module, a shutter module, a metering module in the top, a mirror/prism module and if you will a battery module. Disassembly and reassembly on the 19 is a lot easier than on other model. Unfortunatly spare parts are scarce.
What can go wrong with the Zenit-19?
A word on batteries,Allways try fresh batteries first before dismanteling the camera!
This goes esspecially for the problems of, no led and the led works but shutter shoots 1 speed, try fresh batteries first.
The Zenit-19 and the MT1 (Suprise) use two batteries and the 18 uses four batteries and if you have the databack an additional three are neccesary to make the back work, both 1.35 v mercury and 1.5 v 625's work without problem, meter is NOT affected, the 18/19 has a bridging circuit to deal with the difference in voltage.
If you encounter the following problems,
Main breakdown points of the Zenit-19One of the big problems facing the 19 is contact problems. This can cause the camera to fire at one speed or the meter to stop working. But sometimes the battery check light still lights up. From the bottom to the top runs a bunch of wires. In the bottom they hook up to the electronics module through a connector. Lets look at this one first.
Remove the bottom plate, two or three screws and another located in the battery compartment (18 has more screws).
You are now looking directly at the electronics module (the PCB). The electronics module is held by two or three screws.
At the front, located near the lensmount is the connector that creates all the problems. This happens because the pcb has tinned connectors while the connector has copper ones. You get a small resistance here and it causes a corrosion build up. After a while it gets so big that it becomes a resistor effectively blocking signals. Since you now have removed the bottom, check the battery compartment and clean it. Also check the contactspins, retin them on the electronicsmodule and retin the pins themselves.
Solutions;Disconnect the wires ONE by ONE and Solder them ONE by ONE onto the PCB. Tin the wires first and tin the board first. (makes it a hell of lot easier) After this you can throw away the connector.
Two closeup shots of the connector, plastic with sealed in copper pins.
Warning, after this you will not be able to disassemble the 19 or 18 easily anymore. ONLY USE THIS AS A LAST RESORT MEASUREWorkaround, use contact spray or clean the contacts carefully with iso propyl alcohol or contact cleaner. This works very well if done properly. But the problems can come back. On the other hand, full disassembly is still easier.
A point of advice, resolder board, (in dutch vanwege een mogelijke koude las) to remove bad solderings. In case of the 19 this is very important, these cams are from the early 80's and bad solderings are a common cause for the 19 to break down.
19/18 weak spot, the ISO knob in the left shot, treat it with contact spray.
Time to open the camera up. Once you remove the film advance lever and the rewind know you will finde a small ring on top of the camera. This one is sometimes loose. When it is the top of the camera is loose aswell.
The screw on the advancelever moves counterclockwise once the lever is of there is a secundary screw underneath which holds down the top. When both rewind and advance levers have been removed you can remove one screw from the speed dail, be sure to set the speeddail to B. Now you can pullup the speeddail a little but it can't be removed yet. On the 18 the speed dail can be removed on the 19 however it sometimes can not be removed. See the little piece of metal in the middle of the shot on the speed axis? The speed dail is connected to long rod running through the camera. The little piece of metal on it fits into the speeddail on the pcb.
Remove the little piece of metal, pull it out with a pair of pliers and you can remove the top. Watch the wires inside the top if they are broken your flash will not work. Resolder them just in case. Now you can remove the top.
With the top removed you now have a clear look at the gears module, the prism module (on top of the shuttermodule) and the metering module. The last one needs resoldering. Right shot shows the fototransistor that measures light. Be carefull here. It uses reflected light to work. The elements must be clean.
A not moving needle, either the needle is bust or there is a problem with the wiring or a transistor. I haven't had time yet to work on this, I've made some guesses but simply couldn't work them out yet. But try replacing the needle meter. This seems to work but I can't verify it yet.
The advance and gear assembly, wind lever cocks shutter, shutter fires, wind lever is stuck! press shutter again but deeper, wind lever is freed solution, adjust shutter pawl, left of the main wind gears (it is on the blue button for rewind). You will see that when you press the shutter it pushes a lever near the blue button, you can regulate the height with a screw/nut. Be carefull with adjusting.
In the right shot you can see the foam, if it needs replacing do so.
When the metering module is disconnected (2 to 3 screws dependent on model) there are two screws around the prism. When removed you can take out the mirror/prism module. Again, watch the foam. Replace it.
Also have a look at the mirror spring, in some cases it has become weak. This causes the camera to fire perfectly for several times but then it fails and stops. Replacing the tiny spring for the mirror fixes this.
More mirror problmes. The camera sometimes fires okay for several shots and then fails. If you look at the mirror it doesn't go up all the way. The plate between lens mount and the mirror is bent inwards in some cases, so the front of the mirror can't move all the way up. Bend it back and the problem is gone.
Now you can also carefully remove the shutter module, to make it run more smoothly you can use a teflonspray on it. Watch the springs. It is still connected to the electronics module, check the wires.
The wind and break problem, after that a small rattling noise and the wind lever goes, whiz.... in the bottom is a small rotating knob which cocks the shutter, this one sometimes breaks. You'll need a replacement part for this one (other 19/18/MT1/Suprise)
Left shot, this is how it supposed to look like, the hook cocks the shutter with this pawl which is in turn cocked by the advance lever on the top. The right shot shows a broken pawl, it is gone....
The broken part, this was rattling inside the camera. Next to it its replacement part. I got it from a broken MT1. Replace part and you are all set.