| Author |
Message |
    
Teraforce88
Tinkerer
Username: Teraforce88
Post Number: 1
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 14, 2009 - 04:54 pm: | 
|
I have a Minolta XE-7 that's been having metering issues. When I first acquired the camera, the meter was erratic, but it eventually fixed itself.
However, the meter decided to not read above 1/30 sec at iso 100, no matter how bright the scenery was. Waiting several minutes/fiddling with the battery compartment would fix the issue.
I sent it off to Garry's Camera, but it appears that all he did was set the meter to read up to 1000 without actually fixing the problem. Sometimes it reads 4-5 stops too high at iso 100; other times it's practically stuck at 1/1000 sec. at ISO 100.
Does anyone have any suggestions/hints on how to fix/adjust the meter? I did see several adjustment pots in the viewfinder housing, but I'm not sure what exactly they adjust.
Thanks,
Matt V. |
Bossman
Tinkerer
Username: Bossman
Post Number: 99
Registered: 02-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 26, 2009 - 09:49 pm: |
|
Matt: Sounds like it needs to have someone completly clean all circuits and controls and check for proper ground etc. When I get one like that, I just start with all areas that could cause erratic exposures. I hate those kind of jobs as opposed to one specific problem that you can go to and repair. Art www.flcamerarepair.com |
Chenard
Tinkerer
Username: Chenard
Post Number: 29
Registered: 11-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 27, 2009 - 09:55 am: |
|
Hi Matt,
The metering system in the Minolta XE-7 is fairly complicated compared to many cameras. As you've noticed, there are several pots and switches. Cleaning these might address the intermittency you're seeing. I would suggest carefully noting the exact position of the wipers, and then cleaning them and restoring their original postions as closely as possible.
If this helps, then it will simply be a matter of calibrating the meter after that. The service manual for the XE-7 goes through how to do this. As I remember, it was a fairly involved procedure involving adjusting a constant current source using a dvm. On two of my cameras (one being the meter housing of an XK which is a simlar circuit to the XE-y), it required measuring the resistance of the cds cells under different lighting conditions, and replacing two fixed resistors based on the values, as the cells in my two cameras had aged to the point where a linear calibration using just the pots was no longer possible. There is a table that tells you what resistor values to use based on the readings you get, but for at least on of my cameras, the cds cells had drifted by way too much, and I had to use the equation they gave to arrive at the values.
I remember it being somewhat involved, but I got through it for both cameras, and they now give very consistent slides and negatives under all conditions.
So, why not give the pots a tweak with some cleaner and a toothpick, and let us know if the camera becomes more consistent in its behaviour?
Paul |
Teraforce88
Tinkerer
Username: Teraforce88
Post Number: 2
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 27, 2009 - 06:00 pm: |
|
I actually had a picure of all the adjustment pots before I sent the camera in. I re-set the pots to their initial positions (and wiggled them back and forth several times to break up any oxidation), and the camera is back to its old behavior of not reading above 1/30 sec at ISO 100.
The thing is, though, if I let the camera sit for several minutes or fiddle with the battery contact, I can sometimes get the meter working normally again. There was a period of time where I had to store the camera lens-down (as opposed to camera base-down) because if I didn't, the meter would glitch up. So I'm thinking there's an issue with the battery contact. (I can hear something rattle if I shake the camera vigorously; though I'm not sure that has anything to do with it)
The problem is, I have no clue how to get down to where the wires connect to the battery compartment. It appears as though I really need to tear the camera down quite a bit to get there. I'll probably get a service manual soon to help me out, but is my assumption correct? And is my theory about the battery contact causing the metering glitches plausable? (all other camera functions work fine)
Thanks,
Matt V. |
Chenard
Tinkerer
Username: Chenard
Post Number: 31
Registered: 11-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 28, 2009 - 07:35 am: |
|
Hi Matt,
I missed the part about the camera working normally after sitting.... If there is ever a moment when the light readings are normal over all the lighting conditions, then ignore what I said about meter calibration, cds cells, etc.
I'm not sure I buy into the battery contact idea, because the camera functions (I think) at all times, even when it has the incorrect readings. What does the battery check light say when you think the contact is bad?
At this point I would look next at the resistor strips for exposure, and their wipers. These are the ones that vary with the aperature and asa settings. The strip is underneath the top left cover of the camera, and is activated by a little string, strung through small pulleys, which is connected to the aperture ring. I would give it a good clean, and make sure the wipers are making good contact throughout their operating range.
Setting the asa/exposure compensation dial further rotates the strip. So double check that nothing funky happens to the strip and wipers when that control is turned throughout its range.
Also, when you're following the string's path from the aperture ring to the resistive strip, it should go over a little brass pulley at the front of the camera just to the left of the pentaprism housing. There is nothing holding this pulley in place on its shaft, except spring tension, and the string will slide over the shaft and operate the resistive strip without the pulley present. If your pulley is missing, then might be what is rattling inside your camera.
Paul
Paul |
Teraforce88
Tinkerer
Username: Teraforce88
Post Number: 3
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 28, 2009 - 07:12 pm: |
|
The battery check LED is bright at all times, though I think it's slightly brighter when the meter is behaving normally.
I tried getting the top left cover off, but the setscrew that holds the ISO dial down won't budge.... With the pentaprism cover off, I could see the string running to the meter coupling ring, and didn't see anything suspicious there. However, that string did NOT move when I adjusted the ISO dial (The meter is still affected by the ISO dial, however). |
Chenard
Tinkerer
Username: Chenard
Post Number: 32
Registered: 11-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 29, 2009 - 08:56 am: |
|
To get the iso dial off, I made a tool out of an old screwdriver, filing out the middle of the blade until I had two prongs that fit into the slots of the retaining collar.
The string does not move when you move the iso dial. It only moves when the aperature ring is turned.
Paul |
Rlc
Tinkerer
Username: Rlc
Post Number: 78
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, August 30, 2009 - 10:18 am: |
|
After reading this thread I located my my XE-7 which had not been used in years. With fresh batteries installed I found the meter erratic and sometimes nonfunctional.
After excercizing the ASA dial, the speed dial and the aperture ring thru their entire range several times, I found that readings were operating correctly.
I think it was the aperture dial that was the culprit. It is reading O.K. now and continues to read properly after many trials.
Just lucky I guess but it beats disassembly and cleaning the pots.
Richard. |
Teraforce88
Tinkerer
Username: Teraforce88
Post Number: 4
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 01, 2009 - 06:42 pm: |
|
@RIc: That's what happened when I first got my XE-7: Meter was very erratic. Moving the aperture ring back and forth a few hundered (!) times solved that issue. It worked great for several months, then it started having the problem I'm describing now (Not wanting to read above 1/30 at ISO 100) |
Teraforce88
Tinkerer
Username: Teraforce88
Post Number: 5
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 24, 2009 - 09:53 am: |
|
UPDATE: I just acquired the service manual for the XE-7 the other day. However, I'm back in school, so I won't have as much time to work on the camera as I'd like. I will keep you guys posted if I have questions or find out anything once I do begin taking apart and testing the camera. (I still need that tool to get the silly ISO/Exposure Comp Dial off!) |
Teraforce88
Tinkerer
Username: Teraforce88
Post Number: 7
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 27, 2009 - 02:08 pm: |
|
Okay, I now have a tool to get that setscrew off. Problem is, I can't get the rewind crank off now! I've removed the setscrew that holds the crank handle and "spring" in place, but the crank knob is stuck on the shaft. Does it just press-fit on, or does it screw onto the shaft itself?? |
Msiegel
Tinkerer
Username: Msiegel
Post Number: 133
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 28, 2009 - 03:28 am: |
|
Can't say for sure for the XE-7 but normally those are screwed on the shaft. Procedure normally is to fix the "fork" of the rewind shaft - the part that goes into the film canister with a screwdriver or similar and screw the top off. Be careful not to bend it. In most cases it is not necessary to remove handle and spring to do that. |
Teraforce88
Tinkerer
Username: Teraforce88
Post Number: 10
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 28, 2010 - 12:52 am: |
|
UPDATE: Well, I just took apart my XE-7 again, and noticed that one of the solder joints on the Rp resistor (the little resistor towards the back of the pentaprism) didn't look so good. So I re-soldered it, and the meter pointer flew to the top!
After some re-calibration against a known good camera (my X-700; no fancy calibration tools here!), the meter is pretty close to being good as new!
The only thing now is the fact that when set to "Auto", the camera fires roughly 3/4 stop faster than what's indicated by the meter needle. Any suggestions?
Thanks,
Teraforce88 |
Teraforce88
Tinkerer
Username: Teraforce88
Post Number: 11
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 28, 2010 - 11:56 am: |
|
UPDATE 2: I've fixed the Auto mode glitch mentioned in my previous post. Adjusting R3 ("adjustment of the meter pointer" according to the Service Manual) fixed that issue. |
David_nebenzahl
Tinkerer
Username: David_nebenzahl
Post Number: 233
Registered: 12-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 28, 2010 - 01:41 pm: |
|
Mazeltov! |
Kippaxaus
Tinkerer
Username: Kippaxaus
Post Number: 2
Registered: 12-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 09, 2010 - 05:00 pm: |
|
Can you explain in more detail how you adjusted the meter pointer, as I have a similar issue.
Thanks David |
Teraforce88
Tinkerer
Username: Teraforce88
Post Number: 23
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 10, 2010 - 04:39 pm: |
|
When you say "similar issue", do you mean the issue where the meter won't read above a certain speed no matter what (you could be pointing the camera at a super-bright light source and it won't read above 1/30 second),
--OR--
Do you mean the issue where the Auto mode speed doesn't line up with what the meter is reading? (I.E., the meter reads 1/4 sec but the camera fires at 1/8 sec on Auto) |
Aurelios
Tinkerer
Username: Aurelios
Post Number: 1
Registered: 01-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 05, 2011 - 06:27 pm: |
|
Hi Teraforce,
In my XE-1 (= XE-7) I have the second one: the issue where the Auto mode speed doesn't line up with what the meter is reading (I.E., the meter reads 1/4 sec but the camera fires at 1/8 sec on Auto)
In manual mode everything is OK, I know there is a separate circuit for manual shutter times and this one is good on my XE
How can I manage to fix the problem in auto mode? Have I to adjust R3, R5 or what else?
Thanks in advance,
Aurelio (Italy) |
Teraforce88
Tinkerer
Username: Teraforce88
Post Number: 27
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 05, 2011 - 11:52 pm: |
|
R3 is the one you want to adjust.
Below is a picture of the meter board, which shows all the locations of the various pots (highlight the entire line below; for some reason this forum doesn't parse links correctly)
http://www.flickr.com/photos/38686641@N08/4886466251/ |
Zenzaman
Tinkerer
Username: Zenzaman
Post Number: 12
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 15, 2011 - 10:49 am: |
|
i'm looking into buying an xe-7 that also has some exposure meter issues. the seller says that sometimes the needle goes up and than instantly goes down (the shutter is said to function properly). i concluded the battery connections are fine but there's smth wrong with the exposure meter circuitry (hopefully just a contact). any ideas?
and btw, any chance you could upload somewhere that service manual?
thanks a lot! |
Teraforce88
Tinkerer
Username: Teraforce88
Post Number: 28
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 29, 2011 - 11:32 am: |
|
Zenzaman: It could be that some of the pots are dirty. Try moving the aperture ring and the ISO/ASA dial back and forth a bunch of times to see if that fixes it. If not, then try cleaning the pots under the pentaprism (be sure to take a pic of the pots first so that you remember their initial positions!).
I used to have a similar issue with my XE-7, except the meter would randomly shoot up instead of down. Moving the aperture ring a few hundred times fixed that issue.
At any rate, be sure to handle the camera yourself before you buy, just to make sure that the shutter is indeed functioning properly. Be sure to test ALL speeds, not just X or B (which don't require batteries).
Regarding the service manual: I paid for the pdf version I currently have. I really don't want to upload that service manual because a) I don't want to get sued by uscamera.com, who had originally sold the service manual to me, and b) people would then have free access to something I had to pay for.
I apologize if that sounded selfish, but I will be more than willing to freely share any other knowledge I currently have in helping you out. Keep in mind that I am by no means a camera repair person; I just bought the service manual just so I could figure it out myself.
If you really do want the service manual, I suggest going to http://www.uscamera.com/xesm.htm. This is the place I got my pdf service manual. It's only $9.99, but the wealth of information you get is almost priceless IMO. |
