Frequently Asked Question

TECHNICAL SUPPORT - ISSUE: Photo-eye does not power up (before or after installing a replacement).

Last Updated 3 years ago

Mach 1 semi-automatic wrappers using "DIGI-TECH control unit", including:

Considerations:

It is necessary to use a voltage meter to measure voltages in various areas of the control system in order to properly trouble-shoot issues such as this.
An electrical schematic for this control system is available in the manual that was supplied with this machine.
It’s nearly impossible to get two faulty photo-eyes in a row.
The top/bottom limit switches, turntable counting sensor and photo-eye all run on the same 24VDC supply.
The top/bottom limit switches, turntable counting sensor and photo-eye all get their power source from the exact same terminal in the control panel.
If all the above devices function as expected, except the photo-eye does not power up, the logical conclusion is that there is faulty wiring between the photo-eye and the terminal in the panel.

Connection details:

There is one connection in the junction box on the film carriage where the photo-eye's cable connects to the grey harness that runs to the tower.
The white wire and the blue wire (COMMON POWER, -24VDC) from the photo-eye must be connected to the #5 wire from the harness.
The brown wire (POWER, +24VDC) from the photo-eye connects to #6.
The black wire (SIGNAL) from the photo-eye connects to #2.
NOTE: There may be other wires connected to #5 and #6 that run to the limit switch.
The grey harness runs to the control panel and connects to the terminal strip on the I/O board.
In the control panel check that wires #2, #5, and #6 are all properly connected.
Pull on them lightly to make sure they are well fastened.
Check that they are not shorting with nearby terminals.
NOTE: The SIGNAL from the photo-eye can be seen inside the control panel on the main I/O board (a series of 6 LED's) located next to a green terminal strip. The photo-eye SIGNAL is the second from the bottom. When functioning correctly, this light is on when there is no product blocking the photo-eye, i.e. there is no load on the turntable. It will turn off when a load is placed on the turntable.

Additional follow up:

If all of the above checks out, but the photo-eye fails to power up, the photo-eye(s) must be sent to the factory for testing and determination of next steps.
The services of a stretch wrapper service technician are available, however, installation of parts, trouble-shooting and repair services, and the cost of returning warranty parts to the factory is not covered by the manufacturer's warranty.