ZITAt (-TM- @ 2007-07-27, 12:04) Gibts die oben erwähnte Anleitung noch irgendwo?
Der Link zu Google-Groups ist leider tot...[/quote]
Mit Hilfe von Google Search ist aber in fünf Sekunden der neue Link gefunden: ;-)
http://groups.google.at/group/de.rec.fotog...06d169748307928
Und damit die eigentliche Beschreibung nicht wieder verschütt geht, ziehe ich sie direkt mal hier rein:
ZITATSubject: I fixed my Minolta 7000 (aperture magnet problem)
From: Thomas Steffen <...@iname.com>
Date: 2000-04-02
Newsgroups: rec.photo.equipment.35mm
Hi!
The most common problem of the Minolta 7000 is the failure of the
aperture magnet. The aperture will close down to minimum whatever
value has been set. This posting tells you how to repair the problem.
If you are reasonable comfortable with small parts and soldering, you
have a fair chance of fixing this problem without breaking anything
else. Since the aperture mechanism is at the very hard of the camera,
this posting also tells you how to nearly completely unassemble the
Minolta 7000.
* The problem
Set the camera to manual mode, and select a big aperture (low aperture
value) and a time of about 1 second. Open the back, fire the camera
and lock through it. You should see the lense, and the aperture is
either wide open (ok), or a very small hole (you have the problem).
With some lenses, you can also see the aperture from the front.
* You need
a Minolta 7000 (obviously) with the mentioned problem, 5000 way work.
a soldering iron with a fine tip (SMD soldering).
a good size 1 philips screw driver and a pair of pliers.
a good memory (or take pictures and notes while unassembling).
several hours of time and concentration.
good luck.
* Step 1: Easy steps
Place the camera flat in front of you, viewfinder at the top, the
bajonett pointing upwards towards you. All directions are given for
this view.
Remove the batteries and the two plastic "shields" on the front cover,
they are hold by sticky tape.
* Step 2: Remove the case
Remove the plastic case: top part (6 screws), bottom part (7 screws),
batteries case/grip (2 screws), front part (2 screws). AF has to be
switched on to remove the front part. Take care with the wires to
flash mount on the top part, they could break. Remember where they
lead, just in case.
* Step 3: Disconnect the electronics (for step 4)
There are two mechanical connections, one is under the external LCD
display, the other on the right side near the lock of the camera back.
Unscrew them both.
The other connections have to be unsoldered:
Left of the bajonett, the red and white wire, and the 3-pin foil
connection.
Left bottom of the camera: all 6 pin connections to the pcb, as well
as the 4 wires to the batteries and the 5 wires to the shutter and the
2 wires going around the left front of the camera (black and purple).
Left front of the camear: the leftmost pair of red/black wires has to
be unsoldered.
Top of the camera (to the left of the pentaprism): the orange yellow
pair of wires.
Right of the bajonett: one ground connection (soldered).
(I hope this list is complete, but I might have missed 1 or 2 wires.)
* Step 4: Two halves
It is time to seperate the metal frame with the bajonett and the
plastic case of the camera.
First, unscrew the internal display (in front of the pentaprism) and
the light metering cell (above the viewfinder, back of the camera).
Unscrew the metal base and 3/8" mount (5 screws) and the plate of
metal to the left of it (3 screws). Unscrew the 2 screws left near the
viewfinder (silver ones). Unscrew the last 4 black screws that connect
the metal frame with the plastic case (one in every corner) from the
front.
Now you should be able to seperate the two parts. 2 gray wires (TTL)
are still between them, there is imho no need to unsolder them.
* Step 5: The aperture mechanism
is behind the left part of the metal frame. The magnet is at the very
top (red and white wire), and it can be removed after unscrewing 2
screws and another 2.
It is a permanent magnet, that is temporarily compensator by an
electro magnet. Once it loses its grip, the lever goes into a cog
wheel and stops the aperture from closing any further. If the thing
gets out of ballance (i thing the permanent magnet gets actually to
weak?), it stops working, and the lever just sticks to the magnet.
I made the two contact surfaces of the magnet rough (with a file), so
that it doesn't stick as strong to the lever. This seems to work, but
maybe you have a better idea. You should also check whether the
electro magnet still works.
(If my theory is correct, and the electromagnet is actually too
*strong*, it should be possible to fix the problem without
unassembling the whole camera, by just inserting a resistor into the
circuit. This could be done after Step 2! Please tell me if you have
tried this.)
That's it.
* Step 6: Reassemble the camera
Just go through everything in reverse order. Be carefull when
inserting the metal plate with the one cog wheel and a lever left of
the 3/8" mount. The cog wheel and the aperture mechanism have to be at
its stopper (the lever being closest to the centre of the cog wheel).
Otherwise, the camere will jam instead of winding. Luckily, this seems
to be the only pitfall.
* Step 7: Does it work?
Good luck. If you did everything correctly, the camera should work
again. If not, try again or use it as spare parts. But don't blame me,
I told you that you need some luck. Sorry.
If you have any questions, don't hesitate to contact me. My account
ths (at) who dot net should work for years to come. Maybe this
instruction will make it onto my web page (ths.home.pages.de).
Thomas Steffen[/quote]
Allerdings liegt es nicht an zu starken Magneten, sondern daran, daß die Polschuhe verölt und damit verklebt sind, weil Schmierstoffe in der Kamera sich im Laufe der Jahre zersetzen und an diese Stellen gekommen sind. Die Minolta 9000 AF hat ein ganz ähnlich gelagertes Problem.
Viele Grüße,
Matthias
PS. Siehe auch: http://www.sonyuserforum.de/forum/showthread.php?t=41030
http://www.dyxum.com/dforum/minolta-9000-f...topic86234.html