P21 Digital Back User Manual

All C and CF lenses manufactured since 1957 will work on your 553ELX. The only Hasselblad lenses which will not work are the F types manufactured after 1976 for those bodies which incorporate a focal plane shutter.

You can download a free user manual courtesy of the Norman Butkus website by clicking here.

I hope that my reply has been clear and useful, if so then please spare a moment to rate my answer.

goto samsung.com find your product and you should be able to download manual.

You can download the manual from
http://www.hasselbladusa.com/media/116541/uk_h3d_manual_v4.pdf

(You may have to register your camera first.)

hasselblad makes a digital back--approximately $20,000 USD (yes, that is 20 THOUSAND) and then you need the adaptor (approx. another $1000-$1500 USD). If you can afford that, why not buy a NEW MAMIYA RZ22 (22 mP) or the 33 (33 MP)? would cost less and already digital.

http://butkus.org/chinon/hasselblad/hasselblad_503cw/hasselblad_503cw.htm

Here's where you can download a brochure describing your camera. This is also the website where you can download the owner's manual but you have to register with your e-mail address. http://www.hasselbladusa.com/downloads/product-brochures.aspx

The Hasselblad ELM does not need adapting to use the Imacon or hasselblad digital back  the following backs fit on the ELM and can be triggered with a cable that should be supplied with the back. 
Hasselblad V96c 16mp square format back  Hasselblad CFV 16mp square format back with CF slot Hasselblad CFVII 16mp square format back with CF slot + larger screen
the following backs will work but need to have a V adapter plate fitted to the back 
96c 16mp square format back  132c 22mp 645 format back  528c 22mp 645 format back with Multishot option CF-22 22mp 645 format back with CF slot CF-22 MS 22mp 645 format back with CF slot & Multishot option CF-39 39mp 645 format back with CF slot CF-39 MS 39mp 645 format back with CF slot & Multishot option

When fitting and digital back to an older camera the best advice is to get the camera body serviced to ensure that the back mount is correct as the digital backs require a better fit than the film backs did. If the mount is off it will cause back or front focus. 

This site has a link to downloading the manual:

http://www.butkus.org/chinon/hasselblad/hasselblad_503cw/hasselblad_503cw.htm

I was reading through your user manual and did not see any reset p21. I did find an eject error, which may be of help.

I would first try an emergency eject. Look at page 49 of your user manual. If you do not have a user manual, here is a link to the pdf format version:

http://resources.jvc.com/Resources/00/00/95/LVT1134-001B.pdf

If this does not help, you can always try to do a complete system reset, which should reset it to factory specs. That is located on page 2.

Please let me know here if this helped.

Dean
Rollin CBs

There were several versions of the 500C/M as production was over many years. The 501C had all the latest revisions of the 500 C/M series to make it the better choice. You'll get more $ for the 501 for this reason. Later versions of the 500C/M had a much better coil spring to control the mirror for starters. Unless you are going to use this camera for daily professional use, either would be a reliable camera. A good way to check the amount of use on any Hasselblad is to look at the back of the camera where the film magazine mounts. A good solid black with no shiny spots on the plate would indicate little use. There are raised lines around the aux. shutter opening that will wear as film back are removed and replaced.