Pentax 6x7: vexing battery issue

cooltouch · Joined: 15 Jan 2009 Posts: 9096 Location: Houston, Texas

I just bought a clean old Pentax 6x7 from KEH, had it for about a week. Yesterday, I finally had some time to give it a test drive, so I loaded it up with a battery and . . . that's as far as I got. It takes a 6v battery -- same as the Canon A-series and Bronica ETR-series, and probably quite a few others. Well, I didn't happen to have a new 6v battery handy, so I pulled one from an AE-1P that still had plenty of juice left -- or so I thought. The 6x7's battery check LED wouldn't light up, the shutter wouldn't fire, the mirror wouldn't go up. The meter wouldn't work.

Huh. So I dug a battery out of an A-1 and tried it out. Same difference. So next I pulled a battery from my ETRSi and it wouldn't bring the 6x7 to life either. At this point, I'm on the phone to KEH, checking with them in case I'm doing something wrong, but nope. So KEH sez they'll issue an RMA and for me to send it back.

But I still wondered if maybe I was being too rash. So I went down to the store and bought a new 6v battery. Wow, prices have changed a LOT since the last time I bought one. I was used to paying about $5-6 for one, now they're $10-12. Maybe it's cuz its a new battery chemistry now that's more expensive? The old ones were silver oxide, whereas the new ones are lithium.

Ok, so I install the new battery in the 6x7 and hey! It works! The battery check LED illuminates, the mirror pre-releases, the meter works, and the shutter fires. But now I'm wondering if maybe this old camera might have a voltage problem. I d/l'd a copy of the 6x7's manual from Butkus's site, and in a couple of different places in the manual it states that the camera's current draw is 4mA. That is a tiny amount and it sure seems to me that those used batteries should have had enough life left to handle 4mA of current draw.

So that's what has me concerned. Maybe this old camera has a slight ground leak, for example -- a tiny leak to ground somewhere that increases its current requirements -- and which will also cause a fresh battery to become exhausted faster than normal. From what I've read, these old 6x7s (and the newer 67s) are not battery hogs at all, but this one is behaving as if it might be.

So anyway, if you've got experience using one of these beasties and can give me some perspective, I'd appreciate it. I've wanted one of these cameras for the longest time and I love having one -- finally -- but I want to make sure that the one I keep will be working properly.

pentaxpete · Joined: 02 Dec 2011 Posts: 651 Location: BRENTWOOD England

I bought a 6x7 outfit new in 1981 and it has never had any battery issues -- I also got ' very cheap' a 6x7 Mk II in about 2004 or 2005 and it takes different batteries -- 2 x123A lithiums and I test it occasionally if not in use and SO FAR everything OK ---

cooltouch · Joined: 15 Jan 2009 Posts: 9096 Location: Houston, Texas

Hey Pete, thanks for the feedback. I decided to go for the second model of this camera. The one that I got originally was a 6x7. I "upgraded" to a 67, hoping that any non-obvious wear to the externals and internals would be proportionally less. Well, the upgrade took care of the battery problem I was having. This new camera runs fine on used 6v batteries, whereas the other one wouldn't, so everything is good.

I've added a few items to my 67 outfit as I was able to afford them. Right now, I have the 67 body with metered finder, a 45mm f/4, 135mm f/4 macro, and 200mm f/4. I also have the gray Pentax 2x teleconverter. So I have a decent rig, so far. I'd like to add a leaf-shutter lens at some point, and maybe a fast lens, like the 105mm f/2.4.

pentaxpete · Joined: 02 Dec 2011 Posts: 651 Location: BRENTWOOD England

YEE=Ha !! ( Hope that is 'Texan' for : Greetings from across the Atlantic Li'l Ole England --

Thanks for feedback and glad you enjoy a new 6x7 model -- well now I see you have CANON A-1 cameras -- have you have any problems with the SHUTTER causing severe -over-exposure especially on the fast speeds 1/1000 and 1/500th ? My lovely 'Gift' A-1 is now having that trouble -- I wonder if the lubrication from a 'de-squeak ' of the mirror linkage I did about a year ago has caused it ? Do you think any oil has 'migrated' into the shutter ? I took off the base-plate again and cannot see any oil seepage.

Regards -- Peter

bychance · Joined: 24 Apr 2013 Posts: 347 Location: Kent, England

What lubricant did you use Pete?

cooltouch · Joined: 15 Jan 2009 Posts: 9096 Location: Houston, Texas

pentaxpete · Joined: 02 Dec 2011 Posts: 651 Location: BRENTWOOD England

Thanks for reply -- I used 'Three-in-One' oil just a touch not a squirt !

bychance · Joined: 24 Apr 2013 Posts: 347 Location: Kent, England

Um . . . er . . well -- it's more like Okie for "brilliant!" I guess. Whatever a Brit would exclaim first time he got a ride in a Supermarine Spitfire, would probably be close.

FUC*ING ARS*HOLES!!!......... Shocked

I see what you mean Smile