What does CHA mean on Nikon D-90?
I have a Nikon D90 camera body and today I started getting a
CHAerror on the display on the top of the body that shows f-stop and other settings. Looking around, I do not find a definition for exactly what this means, only suggestions like remove the battery and memory card and reseat them to make it go away, but many say it returns later. What exactly does
CHAmean and how should one resolve it more definitively?
The D90 uses
CHAas a generic 'card error' condition if a problem occurs while the card is in use. If the card works at all or has been working then it's unlikely to be a formatting issue.
This could just be a case of a poor connection and cleaning the contacts on the card and reseating everything may solve it.
If it has been working then there could be a problem with the card in which case you should be able to test it in a desktop machine and retire/replace it if necessary.
There is also an issue I've had with the D90 and larger memory cards (over 8gb) where it incorrectly calculates 'checksums' used to determine if there is a problem (although it writes them correctly) when the value isn't what it expects then you'll get a
CHAmessage. As a temporary resolution you can access the card in a reader and copy & remove the last written file but if this is your issue then the problem will return at some point.
I've been in touch with Nikon about it but without being able to reproduce the issue at will Nikon have not been helpful. The solution I ended up with was just to use multiple cards, which is no great hardship.