Welcome to the site. I'm Dan.
Your 1600W has 3 LED indicators... Ready, Error, and Toner. I need to know what all 3 of them are doing.
Would you say the light is blinking quickly, or slowly?
Sorry, I don't follow. Would you say the light is blinking quickly, or slowly?
I show this link works for your printer also:http://kmbs.konicaminolta.us/wps/wcm/connect/9c24c9e1-4c0a-4c09-98d1-4571478dc5ac/magicolor1680MF_1690MF_4690MF_4695MFFirmwareUpdaterGuide.pdf?MOD=AJPERES&CONVERT_TO=url&CACHEID=9c24c9e1-4c0a-4c09-98d1-4571478dc5ac Using this software, through this software you should be able to download the firmware and install it as needed.
To get the firmware downloader software, you need to request it from the following page: http://www.konicaminolta.co.uk/business-solutions/support/laser-printers-support/magicolor-pagepro-support.html and request the firmware downloader for your printer. I doubt however that it's a firmware problem. Typically when the printer gives an error after an upgrade it's because of a driver issue. I would try removing the printer, downloading the correct driver and doing a fresh printer install.