Battery Problem with Pentax K-M

[glenn_holden]

<p>Just before Christmas, my old *ist DS finally died, well, at least it became unreliable in that every second or third exposure went wonky. Considering it had something like 27,000 exposures on it, I didn't feel to bad. I considered updating to a K7 but my wife used the DS, it was light and simple enough for her- so I always had a backup body for the K10, and I didn't have to carry it. (grin).<br>

Anyway, rather than have it looked at, I bought, on super sale, clear out, the last K-M the photo shop had. It was a good "camera of record" until exposure 2547, that is. Then it got part way through an exposure and the mirror locked up! (Had a fresh set of batterys in it- 2500 maHr rechargeable). Anyway, I replaced the batterys with another set, and it did work again, for about 25 exposures, then it did the same thing. Unfortunately, I was on vacation, so I didn't have time to take a good look at it.<br>

When I got home, I had a good look at the batterys. They all test good on a discharge. It looks like they have tiny pin point weld splatter marks on them. I burnished them up, and took a look inside the battery compartment. The contacts inside are not like the contacts in the cover, they are a piece of small brass bent up with a point on the end with a surface area not much larger than a pin point. I did a light burnish on them, and re-installed the batterys and it's been good for another 100 shots so far without any problem.<br>

I looked at the old dS contacts, it is an entirely different design inside- the contacts are a Y shape arrangement, with much more surface area in contact with the battery.<br>

I now suspect what happens is that the small surface area in contact with the batterys inside the K-M slightly develop some sort of a corrosion, and the weld marks on the battery result from the high current during exposure through a small area, until there is enough corrosion that it prevents enough current flow from activating the mechanism.<br>

Sounds like a design defect to me. Has anyone out there had a similiar problem, and what was their fix?<br>

Sorry, I burnished up the batterys before I thought to take a picture of what the marks on the batterys looked like.</p>

[glenn_holden]

<p>Wow, a couple of weeks, and no response yet. Does this mean no one on this forum ever bought a K-M?<br>

Maybe that is why Pentax discountinued them.<br>

Glenn Holden</p>