Print job will not print from the manually feed tray unless I select the Go button for it to process

Device error An internal error occurred in the device. Press (Select) to resume the job. - Door open The printer door is open. The door must be closed before printing can continue. - Engine comm. error The device experienced an internal communication error. This is a warning message only. Job output might be affected. - Invalid driver You are using the incorrect printer driver. Reselect the printer driver appropriate for your device. - Invalid entry Invalid data or response. Correct the entry. - Jam in Cartridge area A paper jam has occurred in the print path. Open the door and clear the jam. Then press the (Select) button on the control panel - Jam in Output bin A paper jam has occurred in the output area. Clear the jam, and then press the (Select) button on the control panel. - Jam in print paper path. A paper jam has occurred in the print path. Open the door and clear the jam. Then press the (Select) button on the control panel. - Jam in tray 2 A paper jam has occurred in Tray 2. Clear the jam, and then press the (Select) button on the control panel. - Jam in tray 3 A paper jam has occurred in Tray 3. Clear the jam, and then press the (Select) button on the control panel - Load paper The HP Color LaserJet 1600 printer is out of paper. Please load specified paper type into the tray indicated. - Load Tray X [TYPE] [SIZE] The printer is processing job, but the tray indicated is empty. Please load specified paper type and size into the tray indicated. - Manual feed The printer is waiting for paper in the tray indicated Load the paper as indicated. - Memory is low The device memory has been almost completely filled. Allow the device to finish the job, or press (Select) to cancel the job. Break the job into smaller jobs that contain fewer pages. - Misprint The printed pages have been incorrectly placed on the paper. To continue, press the (Select) button on the control panel.

Clean the feed rollers.

Did you re-install your printerdriver? It looks like a driver-problem.

Selecting which tray is used for printing

You can select how the printer pulls paper from the trays.

Understanding tray order

When the printer receives a print job, it selects the tray by trying to match the requested paper

type and size with what has been loaded in the trays. Using an "autoselect" process, it searches

all available trays for the paper that satisfies the request, starting with the bottom tray and ending

with the top tray (tray 1). The printer begins printing the job as soon as it finds the proper type/

size.

Note The "autoselect" process occurs only if no specific tray is requested for the job. If a specific tray

is requested, the job prints from the requested tray.

If paper is loaded in tray 1 and tray 1 is set TRAY 1 TYPE=ANY and TRAY 1 SIZE=ANY on the

Paper Handling menu, the printer will always pull paper from tray 1 first. See "Customizing

tray 1 operation" on page 47 for more information.

If the search fails, a message appears on the printer control panel display requesting that

you load the correct paper type/size. You can load that paper type/size, or you can override

the request by selecting a different type/size at the printer control panel.

If a tray runs out of paper during a print job, the printer automatically switches to any tray that

contains the same paper type/size.

The autoselect process changes somewhat if you customize tray 1 operation (as explained in

"Customizing tray 1 operation" on page 47) or set tray 1 for manual feed (as explained in
"Manually feeding paper from tray 1" on page 49). See if this works. Good luck !

1st thing to do is upgrade the firmware. Go to hp.com and look for the software and drivers. Drill down to the firmware and read the instructions.

It does stand for Manual Paper Feed.
On this printer, that's on the front of the unit, above the paper trays.

Once your PC has sent a print job with the paper-select set to "Manual Paper Feed" the printer will not do anything until it's processed this job.
The easiest way to do this is to put paper into the MPF and let it print, but at some point you're going to want to fix your PC so it doesn't send MPF print jobs anymore.

To do this, open your Printer Properties and select the default paper tray instead of the Manual Feed.

if you using office go to page setup and select the tray(s) that you want to use for the first page and other pages ( both must be the same ) unless you only want the first page as letter head and the rest on plain paper or something along those lines ?

Also if you go into the properties of the printer and go to advanced and then click on the printing defaults button and see if the options in there are the same or different to whats in printing preferences.

If they are set to tray 1 then it will default to tray 1

from the configuration menu you most select the manual tray and keep it first