From doing my research, I have found that the 50C Error message comes from the cartridge, usually if it has been refilled. If this cartridge is new, please return it to the place of purchase for a new one or a refund.

Here's what happens when you refill the series 2 ink cartridges. There is a sensor in them that cannot be reset. Article on refilling Dell ink cartridges  

Dell ink cartridges can only be purchased at Staples, Walmart or Dell's website.

Rick

I have had a lot of problems with my Dell products over the years and I have found that Dell support is not always supportive. I have a A940 which does not get used a lot as I also have a J740. One prints photos better than the other. My problem now with the A940 is that I am getting an error code that my cartridge is stalled. There is not any info to be found on a stalled cartridge. I am not wanting to purchase a new printer as both ink cartridges are full and I don't care to waste money. Anyone have a similar problem?

cmpachel,

Try reading THIS THREAD. It sound like you encoder strip came off.

You can also try the second post at...

Cleaning the encoder strip (Loud bang from printer carriage)

Rick