Disable paper tray size sensors

[JimSchuuz]

We've recently replaced an aging line of older HP LaserJet printers with new M607s.  Among the many differences is the way the paper size is determined.  Apparently, the drawer (paper tray 2) guides tell the printer when the size changes.  Is there a way to disable that so that the printer just accepts whatever size you say is in the drawer (paper tray 2)?  In the first month, we've already had to replace 2 drawers out of 8, and I fear that this is going to be a problem going forward.

Just to explain, on one the printer kept saying that the paper size was A5 and on the other it kept saying the paper was Legal size, but both drawers were set to Letter.  Placing the problem drawer into another printer made the new printer think the paper size changed, so the problem was with the drawer.  Swapping the drawers to brand new ones from HP under warranty fixed the problem.  Everything on the drawers appears to be mechanical, but to the naked eye I wasn't able to see any difference between a good drawer and bad drawer.  Has anyone else seen this same type of problem, even if it was just isolated?  Can the auto-sensing size option be disabled?

[Valsimot]

The printer has media size detection electronics that is a combination of switches and levers.  Depending on the combination state of switches ON or OFF printer knows what is paper size.

On paper drawer when you remove it on the left side should be mechanical levers that change their positions depending on size adjustment levers in the tray.

So when you adjust one paper size the levers on the drawer are set to one position, and that levers on drawer are pressing levers ( switches) inside printer so the printer knows what is the paper size when a tray is inserted. if you change paper size in the tray the combination of levers change on the left side of the tray, and when inserted the combination of switches is changed so printer knows the paper size.

if you look inside the printer with a removed tray on the left side you will see something like this:

That is the part inside printer for detecting paper size.  It can't be disabled, but the problem is in the drawer, so if you still have the old ( bad) drawer compare on the left side when set to the same paper size levers there should be differences. Press with a finger each lever on a tray and you will feel differences between lever positions.

[JimSchuuz]

Unfortunately, I already returned the problem drawers back to HP so I'm not able to inspect them at this time.  Thanks for telling me where to look the next time... perhaps I will be able to fix the drawers myself instead of having to go through the warranty exchange process.

It's important to note that several drawers did require some work on them after setup because the gears were out of alignment - presumably from shipping.  However, I don't remember having had to work on the specific trays that had to be returned, so maybe this won't actually be a problem going forward.  I just have to make sure they are all operating at peak performance because 75% of our office's annual work is done in the first quarter, and January will be here very soon.