No Signal message on density meter
A No Signal message could be caused by a faulty density meter display or a problem with the PC motherboard.
When the density meter is powered on, you should immediately hear one beep which is firmware related. After about 5 seconds, there should be another faint beep which is from the PC motherboard.
If you hear two beeps (total): please try connecting an external monitor to the VGA port on the back of the DDM. If you see the user interface on the external monitor, the problem is the display itself.
If you do not hear the second beep (only hear 1 beep): the issue is the PC booting.
First, you should replace the PC motherboard on-board battery, this battery can be purchased locally (battery number CR2032). After replacing the battery you will need to go through the BIOS restore document.