QLn 420 How to position for Tear Off

Hello.

We bought a QLn 420 for Demo perposes.

We would like to print labels by CPCL driver and by ZPL.

I didn't succeed to make the printer position after a CPCL label correctly, so that the tear off bar is in front of the label gap after printing a label.

I tried to configure some values using the driver, send configuration using Zebra Setup Utility and creating a RUN.BAT file with

PRESENT-AT and / or SETFF commands.

Nothing helped. Either the label doesn't come out far enough or too far, but completely inconsistently.

And there is another problem: It prints only every second label, after one label the next only some dots/lines are printed...

We are using black mark paper of 152,4mm length and 104mm wide.

The printer is connected via USB (currently).

When printing the Configuration Info from the Printer Menu, it (now) says:

...

Tear Off: +000

Print Mode: Tear Off

Media Type: Mark

Sensor Select: Reflective

Print Width: 623 ---> this is only 79mm!!!

Label Length: 1230

...

Backfeed: Before

Label Top: +000

Left Position: +0000

Reprint Mode: Disabled

Web Sensor: 020
Media Sensor: 024
Take Label: 128

Mark Sensor: 027

Mark Med Sensor: 027

Trans Gain: 153

Trans Base: 000

Trans LED: 059

Mark Gain: 164

Mark LED: 055

Resolution: 832 8/mm Full

Link-OS Version: 4.0

Firmware: V68.20.01Z <-

...

Hardware ID: 6.5.0 3.42

RAM: 8192k R:

Onboard Flash: 65536k E:

...

ZBI: Disabled

What am I doing wrong?

Any additional info needed?

I now wasted about two days of work and more than 2 rolls of paper trying to configure the printer to work correctly...
:-(

I already asked our vendor, but he was not very helpful...

With kind regards,

Harald Henkel