On my D200, I am getting a CHR or CHA, can't tell if it is an A or an R, on all my CF cards. They used to work. I can read the cards on my PC. It wil ot take pics or format. Any clue?

Dear Sir e_jamandre, probably the connector memory card has one or more bent pins or cracked solder.
The worst thing would be that the memory compression circuit is damaged.
Greetings

If there are brackets around the CHR, it means the card is locked. SD cards have a slide switch along one edge. The position farthest from the contacts locks the card, protecting it from writes. The position nearest the contacts unlocks the card. If the switch is already in the proper position, slide it fully the other way and then back again.

If there are no brackets around the CHR, it means the camera cannot read your memory card. Try a different card.

When you removed the card from the computer, did you remember to use the "safely remove hardware" function? You are formatting the card in the camera, right?

Card error.

I had the same problem and thought I had looked closely at the pins in CF slot but after finally taking it to a repair shop, the tech showed me a bent pin. It really wasn't that apparent first time around. He told me its a common problem as long as they use the CF cards. I had the pins replaced and my D100 is working great. Best of luck.

You can always try the reset button. It is under the flap where the USB/Video out/ and power connector is. It is just above the power connector.

Is you camera plugged into you computer. If so, you cannot format the card from the camera, unless it is unplugged. This just happened to me (I was about to look for a bent pin). Unplugging solved the problem.

I assume by "microdrive" you mean the compact flash card - right? Not all compact flash cards will word with the D200 - what is the brand of each of the flash cards you have (and are they all the same-purchased at the same time)?

Have you done the firmware update? If not the update is available here: CLICK HERE FOR MACINTOSH or CLICK HERE FOR PC.

If that didn't solve your issue, you may have to go to an authorized Nikon dealer to have the camera reset. The internal battery cannot be serviced by untrained persons. I would also suggest that going forward, you carry your camera inside your coat when you're outside in cold weather, since electronics are easily damaged (especially software) by frost and / or water vapor which can very easily damage parts of your camera (hardware and software) in any weather.

try another cf card first. if the trouble is still the same,  there is an internal malfunction in the unit, you need pro fix then.. [:0(