Minolta (Maxxum/Alpha) 7000 AF: Tutorial for removing the mirror box and shutter unit, notes on assembly, adjusting the Copal S shutter

[Andreas Thaler]

In order to access the shutter for repairs or replacement, the mirror box on the Minolta 7000 AF must be removed. The same applies to fixing problems with the aperture control or the mechanics of the mirror box.

This tutorial shows the necessary steps.

The basis for this is the Minolta Service Manual and an issue of the SPT Journal:

Minolta Maxxum 7000 Service Manual

Factory service manual and SPT repair guide

learncamerarepair.com

-> See page 139 (PDF) for removing top and bottom cover.
-> See from page 159 (PDF) „Mirror box set removing“

SPT Journal 1997

Issue dedicated to the Minolta Maxxum 7000

learncamerarepair.com

-> See page 19 (original) „Sequence“ for removing top and bottom cover.
-> See page 21 (original) „Sequence to remove mirror box.


Notes

1. This tutorial follows both sources for the most part, but I deviate here and there from the order of the steps as they are listed in the SPT Journal (author: Larry Lyells). Especially in the finale, when it comes to desoldering cables in the bottom area.
2. This process worked for me, but I strongly recommend familiarizing yourself with both sources before starting work. There you will also find additional tips and explanations.
3. I am removing the mirror box from a 7000, where I have already done this before. So this is no longer the original camera mounted by Minolta, which may be relevant given the various screw types that I may no longer have assigned correctly. I have also already replaced two black textile adhesive strips with white insulation tape.
4. I found no indication in either the Service Manual or the SPT Journal that the camera needs to be adjusted after assembly.
5. I investigated the last part - the shutter unit removal - myself without instructions. According to the service manual, the shutter is very sensitive and should not be taken apart. This means that if there was a problem, it was obviously completely replaced by Minolta. You should be able to read in the service manual and SPT journal whether adjustments need to be made after a replacement.
6. All parts are resistant, the camera even stood upside down without the top cover, so I didn't need a vice when working.
7. All screws could be removed without any problems.
8. I recommend using a grounded work mat to protect the ICs from electrostatic discharge, which is also the instruction in the service manual. See Post in thread 'Minolta (Maxxum/Alpha) 7000 AF: Aperture issues resolved/shortcut, viewfinder display/main LCD replaced, mirror box removed, aperture ring exchanged'https://www.photrio.com/forum/threa...d-aperture-ring-exchanged.211422/post-2867118
9. Good luck! If you have any questions, please do not hesitate to contact me
   
10. All information provided without guarantee and use at your own risk.

---

Removing the mirror box

The candidate.

Remove bottom cover, 7 screws.

The screws are different lengths, this picture is not a reference (see start of this posting, „Notes“, point 3), so please pay attention when loosening them.

Top cover, 7 screws.

Handle inside, latch with screw.

5 cables to the hot shoe connect the top cover with the housing, desolder (brown, black, white, blue, purple).

Before desoldering, cover the LCD with tape to protect it.

With flux, desoldering is quick and the solder joints retain their shape.

Done

Removing the handle, 1 screw.

 

[Andreas Thaler]

The two covers on the front panel are attached with double-sided adhesive tape and can be carefully pried off.

When you remove the front panel, the selector switch is set to AF.

Front panel, 2 screws.

This is how the selector switch is installed.

Part of the gearbox, 2 screws.

Measuring cell, 1 screw.

LCD holder, 2 screws.

Connector with rubber pad, 3 screws.

The connector fixes these two flexible circuit board parts, which are aligned with pins.

Desolder 2 cables (yellow, green).

The cover plate above the LCD unit of the viewfinder is fixed with double-sided adhesive tape and can be levered off. Be careful, it bends easily.

 

[Andreas Thaler]

LCD unit of the viewfinder, 2 screws.

For the next step, I moved the LCD a little to the side and fixed it with adhesive strips to make room for the desoldering work.

Two flexible circuit board parts are soldered here including 1 cable (black).

Desoldering with desoldering braid. Apply flux on the braid and the soldering points.

Done, the two board parts and the black cable are separated.

Desolder 1 cable (light grey; the blue piece of shrink tubing I used for another project and is not an original Minolta one).

Desolder 1 cable with two wires (grey).

Desolder 4 cables (yellow, orange, black, purple).

Attention, there is a second yellow cable that remains soldered.

Desolder 2 cables (red, black).

Desolder all cables except those in the 2 markings and except both the thick black and red one accross.

Desoldering the 6 holding points for circuit board part on the case.

 

[Andreas Thaler]

For this I use a desoldering suction pump.

Loosen 1 screw.

The circuit board is now separated from the housing.

Tripod plate, 5 screws.

Connector, 2 screws.

Desoldering this fixing point that holds the board to the housing.

Desoldering this fixing point that holds to parts of the flexible board.

Only the upper board needs to be desoldered, the lower one stays where it is

Loosen 1 screw.

Loosen two screws.

Carefully pull this part of the flexible board out from under the LCD.

 

[Andreas Thaler]

2 fastening screws for the mirror box on the left …

… and 2 fastening screws on the right.

The white arrow points to a plastic fixing pin that breaks easily, so be careful when pulling out the mirror box.

Now the mirror box can be separated from the rear part of the housing. Be careful of cables that may still need to be led out.

Once all connection points have been completely loosened, the mirror box can be pulled out without resistance.

Congratulations, that was some work!


Removing the shutter unit from the rear part of the housing

-> See start of this posting, „Notes“, point 5.

The shutter is fixed to the rear housing part at two points.

Bottom left and …

… bottom right.

Here are the pins on the back of the rear part of the housing that are used to attach the shutter unit.

Be careful that the two circlips do not fly away when removing them.

All shutter control connections converge here.

The cables remain on the shutter control, are unthreaded and now the shutter unit can be carefully pulled out downwards.

All removed parts at a glance.

Reassembly is carried out in reverse order.

-> See service manual from page 162 (PDF), „Mirror box set installing“, especially the note on coupling the mechanism for assembly.

-> See SPT Journal from page 21 (original) [Mirror box] „Reassembly highlights“.

+++

All information provided without guarantee and use at your own risk.

 

[Andreas Thaler]

Reassembly is carried out in reverse order.

-> See service manual from page 162 (PDF), „Mirror box set installing“, especially the note on coupling the mechanism for assembly.

Preparations for assembling

Before assembling the mirror box and housing, the charge lever must be positioned on the mirror box.

From this position …

… by moving the lever in the direction of the arrow …

… to this position.

On body side complete winding of sprocket and take-up drum. Lock take-up drum, turning it in winding direction.

-> See page 108 (PDF) in the service manual.

 

[Andreas Thaler]

I investigated the last part - the shutter unit removal - myself without instructions. According to the service manual, the shutter is very sensitive and should not be taken apart. This means that if there was a problem, it was obviously completely replaced by Minolta. You should be able to read in the service manual and SPT journal whether adjustments need to be made after a replacement.

Note: I replaced the shutter unit on a Minolta 7000 AF and did not notice any problems when measuring the shutter speeds:

Post in thread 'Minolta (Maxxum/Alpha) 7000 AF: Aperture issues resolved/shortcut, LCDs replaced, aperture ring exchanged, shutter unit replaced'
https://www.photrio.com/forum/threa...ged-shutter-unit-replaced.211422/post-2869638


+++

All information provided without guarantee and use at your own risk.

 

[Andreas Thaler]

Adjusting the curtain speeds of the Copal S shutter on the Minolta 7000 AF

Once the mirror box is removed, access to the shutter unit is clear.

To replace it or adjust the curtain travel times, the shutter unit must be removed from the back of the 7000 AF. This is easy; only circlips or screws have to be losened.

To adjust the curtains, you need a camera tester that can measure the curtains travel times. For the Minolta 7000 AF, this is 7.2 milliseconds each. I use the Reveni Labs Camera Tester.

Detailed information can be found here:

Minolta (Maxxum/Alpha) 7000 AF: Aperture issues resolved/shortcut; LCDs, aperture ring, shutter unit replaced; aperture solenoid cleaned

There is always too little space on the table for such work 😌

www.photrio.com

Copal S(quare) Shutter: Testing when removed?

I am currently working on the Minolta 9000 AF shutter, which has problems with a rotting damper that is sticking the blades together. An attempt to clean it from the outside while it was removed was unsuccessful; the shortest times of 1/4000 to 1/1000 s are not formed or are not formed...

www.photrio.com

Copal S(quare) Shutter: Testing when removed?

Now everything is ready for checking and adjusting the shutters on the Minolta 9000 AF and 7000 AF on the camera tester. However, they must first be removed. Then we can proceed.

www.photrio.com

+++

All information provided without guarantee and use at your own risk.