Balanced Audio REX II Power - Manual (Page 10)

In other cases the tube might continue activating the protection circuit,
indicating the need for replacement.
The standard recommendation is to ignore the first occurance, and
replace the tube following any further events.
What to do when the LED light goes out :
If you notice that one or more green LED’s goes out, the first step should
be to RECORD THEIR POSITIONS.
Then turn the unit OFF by using its main power switch, wait a couple of
minutes and turn it back ON.
If the same tubes exhibit the same fault again, they should be replaced.
While it is always best to replace a matched pair of tubes, it is not always
absolutely required. If your unit is farily new, then you might consider
replacing just one faulty tube. The factory can supply a tube with similar
characteristics.
Replacing the Fuse:
WARNING: Please turn the unit OFF and disconnect the power
cord before proceeding.
There are NO internal fuses in the REX II Power amplifier.
The main power fuse is Slow-Blow type, located on the amplifier’s back
panel, and should only be replaced with the same type and rating fuse:
100-120V 10A
200-240V 7A
If the unit still fails to operate properly, please contact the factory for
professional service.
Factory supplied fuse should only be replaced with the same
type and rating part.