OM POWER OM2000+ Manual page 37

Plate voltage error
Grid voltage is low
Screen voltage error
Amplifier is too hot
HARD FAULT
Heating voltage error
Cooling error
Mains error
Check plate power supply
Check grid power supply
Check screen power supply
Check cooling system
Set up additional blower
Check HV circuits and Tube
Set up proper transformer
voltage selector
Check blower rotation
Check mains voltage and set up
nominal mains voltage Set
up proper transformer voltage
selector
High voltage supply fault. Check the fuses on HV board.
Low voltage on the grid. Check fuse F9 on HV supply board.
Check fuse F10 and F11 on HV supply board and fuse F1 on
the Screen board.
Check the airflow (ventilation grid on the rear panel).
Cooling exhaust must be free from any obstructions. During
extended use set the blower speed to ALWAYS ON (page
16).
Protection circuit saved HV against overload. If high current
from the HV supply caused the HARD FAULT then is
activated the protection and the PA is automatically
switched OFF. Check HV circuits, blocking capacitors and
the tube itself.
This error is usually due to improper setting of the primary
voltage on the transformer (page 27). In normal condition
filament voltage Uh readings should be 9V +/- 0,3V for FU-
728F tube.
Main blower problem. Check its functionality.
This error may be caused by the improper setting of
the nominal value of Um. Check your AC mains
voltage and set it as nominal Um (page 18). Check the
primary voltage setting on the transformer. This fault
may also be caused by "soft" mains, when during
transmitting the AC voltage drops to a very low level.
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