Minolta X-700: A renovation project

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
As announced, the first project in the new year will be the renovation of an X-700 with obvious moisture damage.

Today the cheaply purchased and well used X-700 arrived and I did an initial inspection.

The goal is not to get the camera back to full function at all costs, but to see what damage is present and what techniques can be used to repair it.

I draw on my own experiences with the X-700/500/300 as well as a tutorial from Simon Pate, Learn Camera Repair, who repaired a X-700 with water damage:

Minolta X-700/500/300 (700/570/370): Recommendations and notes

Timeless, robust and reliable classics: the three Minolta X SLRs from the 80s Based on my previous (repair) experiences with the Minolta X-700/500/300 (X-700/570/370) cameras with regard to preservation/problems/repair options, I would like to give a summary of the following...
www.photrio.com

Minolta X700 CLA Tutorial

Tutorial by Gene Pate
learncamerarepair.com


There is an article about repairing water damage to cameras in a 1977 issue of the SPT Journal, which I will also include:

Water damaged cameras

There is a detailed report on this topic in the SPT Journal September/October 1977, which was just published on Learn Camera Repair: https://learncamerarepair.com/product.php?product=1750 I think fixing water damage to a camera is the most work with the least chance of success. Corrosion is...
www.photrio.com

There is also a reference to Thomas Tomosy in the article on PHOTRIO, who is dedicated to the topic.


Unfortunately I'm still dealing with COVID, but I hope to be able to start in the next few days

Here is a preview of the condition the camera is in:




















 
Last edited:
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
I'm curious to see what it looks like under the casing. This also provides information about how protected the X-700 is against environmental influences.

Even specimens on my workbench that were very dirty on the outside were clean on the inside, which suggests that the housing protects very well even without special seals. But it remains to be seen whether this is also the case with humidity.
 
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
I suspect that the camera was stored in a damp place for a long time, as indicated by the numerous signs of corrosion. You can see this very clearly in the two screws beside the eyepiece, which are made of metal.

The batteries have leaked or are corroded, but the battery contact in the battery chamber is clean.

The screw on the winding lever has come loose, maybe the spring inside is rusted.

The exposure compensation wheel release button is stuck and there are fungus spots on the mirror.
 
Last edited:
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
The question is whether I can even remove the case if the screws are rusted. But there are enough spare parts available and therefore less elegant methods can be used if necessary

I'm excited anyway to see what will happen
 
Last edited:
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
Tomorrow we go!

I'm also writing this to commit myself since I'm still tired but able to work again after COVID, thank God.

I'm excited to see what challenges this moldy X-700 has in store
 

ic-racer

Member
Joined
Feb 25, 2007
Messages
16,485
Location
USA
Format
Multi Format
May need to drill out the screw head...
This camera was repaired, I think I can just put a dab of paint in the hole and it will look ok. For extra points I could put a fake screw head there.
 

ic-racer

Member
Joined
Feb 25, 2007
Messages
16,485
Location
USA
Format
Multi Format
Small drill bit. Just the head was drilled out. The shaft of the screw is still in the camera.
 
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
Andreas Thaler said:
Tomorrow we go!

I'm also writing this to commit myself since I'm still tired but able to work again after COVID, thank God.

I'm excited to see what challenges this moldy X-700 has in store
Click to expand...

Unfortunately, the project still has to wait. The head works but the body is still tired. But it will be okay. This is how I learn to wait for something. A good but hard exercise for me
 
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm



Back at work after a long illness break!

It's 9:25 a.m. (CET) in Vienna.

I'm excited to see how far I can get today.
 
Last edited:
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
1:15 p.m. (CET) in Vienna, I'm writing the first summary.







To test the power supply, I clean the battery holder and the contacts in the battery chamber with electronics cleaner. Also the screw thread that makes contact with the camera ground.




Despite the obvious effects of moisture, the light meter works. Incredible! Only the displayed times jump around when I turn the ring on the bayonet with the lens/light meter coupling. The wipers and contact tracks are probably dirty.




The main switch can only be turned with force. In the ON position with signal, the LEDs in the viewfinder do not light up. Probably also a contact problem.




With the probe I was able to scrape rust off the screw head profiles so that the screwdriver would grip.





The left screw is tight. I put WD-40 on it.




Front




Maybe I should have waited longer to allow the WD-40 to work more. In any case, I overtightened the rotten screw head.








I use the Dremel and a tungsten carbide cutter to remove the screw head. This also removes material around the hole in the top cover. A smaller cutter would be an advantage. But I will repair the spot later with Sugru.

I can't unscrew the stuck remainder of the screw from the thread with the pliers. This is not a disadvantage, the top cover is also one screw less tight.

So there is a cosmetic task waiting for me here.




The top cover comes off now.








Dirt can only be seen along the edges of the case.
 
Last edited:

koraks

Moderator
Moderator
Joined
Nov 29, 2018
Messages
20,697
Location
Europe
Format
Multi Format
Andreas Thaler said:
I use the Dremel and a tungsten carbide cutter to remove the screw head. This also removes material around the hole in the top cover. A smaller cutter would be an advantage. But I will repair the spot later with Sugru.
Click to expand...

If you put the Dremel in a drill press stand, you can drill much more precisely and thereby prevent collateral damage as happened here.
I doubt Sugru is very useful for this particular application. I don't really see how it will make a sufficiently reliable fix with the required mechanical strength here. That top lid is basically FUBAR; too bad, maybe find a replacement on a broken donor camera.
 
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm






Even on the front there is only dirt on the edge of the case.




There are two tantalum capacitors installed in the upper deck. This is good news because, unlike capacitors with liquid electrolyte, these cannot leak. So I save myself the work forward on the circuit board to check the capacitors. I'm assuming they work.






I unsolder the cables between the top cover and the housing so that I can clean the cover thoroughly.




Removing the bottom cover. A lot of dirt and some corrosion is to be seen.




A tantalum capacitor is also installed here. It should be ok too.






The tools from ifixit for opening smartphones can be used optimally here.




I had bent this contact.

But it can be easily corrected later.




A screw is missing here. Where is it? Under the table? But replacements are available.




The bayonet ring is removed and the contacts to the exposure metering system are accessible.




The mechanism that transmits the smallest aperture on the lens for the program automatic is dirty and stiff. It will be cleaned later.




The wipers for transmitting the aperture values on the lens are worn out. I will replace the ring.
 
Last edited:
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm

I'm just going to touch this up cosmetically since I can't get the rest of the screw out. Sugru is good for this. I then have to separate a screw head from its thread and fit it. So that the illusion is perfect

But I can also replace the top cover.
 
Last edited:
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm


The contact tracks for the wipers waiting to be cleaned.




The retired ring with the wipers.




So that I don't lose the screws and mess them up, I screw them temporarily into their holes.




The contact is bent back.

I then work on it with the small pliers.




Overview




The leatherette on the right is heavily worn. I will replace it.




Things have now come to life at the table






Break - and a late midday meal
 
Last edited:
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
It paid off to do this exercise. This is how I quickly progressed with the dismantling today:

Minolta X-700: Removing the mirror box and shutter

Today I would like to take a closer look at the mirror box and shutter of the X-700. To do this, the camera must be partially dismantled. It's a bit of work, but if you are familiar with a screwdriver and soldering iron, it can be done without any problems. Tutorial bei Gene Pate, Learn...
www.photrio.com
 
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
koraks said:
If you put the Dremel in a drill press stand, you can drill much more precisely and thereby prevent collateral damage as happened here.
Click to expand...

The boundary of the hole then becomes regular with the drill stand, but with the shape of this milling head it hardly gets any smaller.



Because until the screw head is off, it goes in a bit. The smaller milling heads from Dremel don't grip the metal of the screw, nor do my drills.

Here I have again reached the limit of what I can do when it comes to metalworking at home. I can't fit anything more than the Dremel here.

But perhaps there are smaller milling heads made of tungsten carbide from other manufacturers?

Recommendations?
 
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
6:53 p.m. (CET) in Vienna, here is the next interim report.





I removed the lens/camera coupling ring from an abandoned X-700.




Here are the wipers in perfect condition.




I decided to replace the entire leatherette, which also saves me cleaning.

Below are the old parts and above are the parts from the spare X-700.




The contacts are now fully aligned. The candidate in the front and an abandoned X-700 in the back as a reference.




Cleaning with isopropyl alcohol.




In order to be able to completely clean the clutch mechanism including wipers for the program automatic and the area underneath it, I remove it.

Cleaning with isopropyl alcohol and aqua purificata.




Before cleaning …




… and then




The clutch mechanism is reinstalled, I attach its spring.




A little Ballistol silicone oil allows the parts to slide together without friction.

The lower part of the spring is still adjusted to the groove.

A Glock pistol can be seen on the bottle in the background. A quality product made in Austria




Cleaning the bayonet rings before assembly.




The mechanics around the bayonet are now cleaned, oiled in spots and installed. Everything is running smoothly again.




Things will continue soon.

Next step is cleaning all disassembled parts.
 
Last edited:
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
By the way, I have no idea whether the camera will trigger.

The winding lever was already partially dismantled, so I took the top cover off straight away to look under the hood.

For this project, my focus is on cleaning and getting things partly back into working order.

If the camera works in the end, I'll be even happier
 
Last edited:
OP
OP

Andreas Thaler

Subscriber
Joined
Nov 19, 2017
Messages
4,353
Location
Vienna/Austria
Format
35mm
Cleaning the removed parts




The parts are bathed in a bowl of warm water with a generous dash of Durgol descaling solution for about an hour.

It's best to use a sieve for this so that small parts such as screws don't get lost.




The diluted descaling solution removes some dirt as well as residues of battery acid and corrosion.

Where small air bubbles rise, the process is active. As can be seen here on the base plate.
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…