Empty cartridge indicator, yet cartidge is new

on ours the cartridges click twice to be fully seated..there are 4 cartridges in this one.. if one is not all the way down, it will error..in extreme cases if all the cartridges are in place..unplug the unit and reboot it..

Are you sure its exclamation mark?..
This warning message related to print head. (warn out). When you are replacing ink tube assembly use dummy print heads to do the priming (new ink tubes are empty & they have to fill with ink)..
Action: Remove all cartridges and print heads, switch on the printer follow the screen message.(Insert cartridges first next dummy print heads).once its recognizes cartridges then it switch over to print heads,insert dummy print heads. Once printer recognized the dummy print heads, printer will perform priming, during priming dummy print heads will filled with respective inks.(follow the display message)Remove dummy print heads & insert normal print heads. Wait till printer recognizes print heads, load the paper & wait till performs the calibration, once calibration is successfully done issue closed.
If calibration not successfully done, check align print out for which print head is not printed properly, replace it..
Pl ensure that minimum 50% ink levels required in cartridges before performing the priming. Best of luck..

I think you need to change the magenta cartridge.

maybe the cartridge is wrong, release it and clean the electrical contacts, put them again one by one, if notting happen, try this
Solution As the printer operates, it moves ink from the ink cartridges into a printhead reservoir. The printer does not deliver a message when an ink cartridge goes empty, because it still has ink in the reservoir. The printer continues printing until the ink level in the reservoir falls to a first trigger point - then a message appears advising the printer owner to Replace Cartridges Soon . At this point, other cartridges that are empty but have not reached the trigger point are also mentioned in the message, to save trips to the retailer. After the first trigger point, the printer can continue printing until ink levels in the reservoir reach a second trigger point. At the second trigger point there is only enough ink left to perform vital servicing tasks, and a new message appears, saying Ink Cartridges Empty . The options offered depend on the usable inks remaining. If no options are offered, the cartridges indicated must be replaced before printing can continue. The Ink Cartridges Empty options are described in the table below: Ink colors out Option Print mode possible All Cancel None Black

AND

Cyan, Magenta, or Yellow (any or all) Black only Continue with other colors Cyan/Magenta/Yellow mode (composite black)

Text and photo quality will differ from those printed when all colors are available Light Cyan or Light Magenta (either or both) Cyan, Magenta, or Yellow (any or all)

(Black still available) Print with black ink only Grayscale

Try remove all cartridges then put back it one by one.Make sure the color cartridges are not empty too.The printer need all cartridges not empty to initialized and working.

There are only 2 reasons why this problem happens to your printer:

1) This usually happens if your printing heavy graphics.
2) You are using HP refilled ink

Take note HP always suggest us to always replace your ink with original HP ink cartridge

HP Deskjet 3915 Inkjet Printer.

Empty cartidge status is related to the refilled catridges.

Please do not use any refilled cartriges in the above printer.

There is a chance of leakage of ink as a result the entire printer will not work properly.

Buy genuine HP Catridges and install the same in the printer.

If the problem still persits, please lodge a complaint with local HP office and get the cartidge is replaced with a new and genuine one.

Try to make user of Annual Maintence serice contract with local authorized ho Vendor for regular servicing of this printer.

slowly off and on the printer for five times without cartridge, printer saves data of cart of last 5 only so next time it reads full ink..

If the error message is only "magenta/cyan low", it doesn't cause any error. The low message stays after replacing ink cartridges if they're replaced too early (before they're indicated as actually empty), it doesn't cause the printer to not work.
However, some other problem might be faulty, or there might be another error message. Try emptying printer queue and print from Ink Management -> Menu/set (twice) to check wether the problem is with communication from pc or if the printer actually is unable to print.

This is only a reminder! The cart will show "empty" when it is really empty. You can print on until the printer stopps because of empty cart (and prints on when it is replaced).
Take the new on out and put it in again. answer display question with "1" (Yes, cart changed). "Near empty" Message will disappear.