No Printing Is Performed; The Interface Malfunction - Brother P-touch QL-700 Service Manual

[4]

No printing is performed.

Tape feed is normal but cannot print.
Is the print head cable
connected correctly?
Is the thermal head
appearance normal?
If replace the main PCB
Replace the power supply ASSY.
[5]

The interface malfunction.

The interface malfunction.
connected correctly?
Is the USB cable damaged?
The USB cable is defective.
Replace the cable.
N
Y
Y
N
Y
ASSY, is it OK?
N
Is the USB cable N
Y
Y
N
Correct the connection.
Replace the thermal head ASSY.
Replace the main PCB ASSY.
Correct the connection.
Replace the main PCB ASSY.
IV - 10