Hey,
I recently bought a vx1100 monitor second hand and thje other day went
to switch it on and nothing happened.
I opened up the monitor and found the fuse had blown.
I notcied the fuse in there said t3.15a 250v , although marked on the
circuit board was t4a.
Ireplaced it with another 3.15 a, which blew straight away, so i
replaced with a 5a fuse on the basis that it asks for a 4a and the
nearest i had was 5a.
The fuse did not blow but the unit does not start, no green l.e.d on
the front power switch. no noise , nothing, there were no obvious burns
inside the case!,
any ideas guys?

cheers
muncey

wrote:
Hey,
I recently bought a vx1100 monitor second hand and thje other day went
to switch it on and nothing happened.
I opened up the monitor and found the fuse had blown.
I notcied the fuse in there said t3.15a 250v , although marked on the
circuit board was t4a.
Ireplaced it with another 3.15 a, which blew straight away, so i
replaced with a 5a fuse on the basis that it asks for a 4a and the
nearest i had was 5a.
The fuse did not blow but the unit does not start, no green l.e.d on
the front power switch. no noise , nothing, there were no obvious burns
inside the case!,
any ideas guys?

cheers
muncey


No insult intended but...
My idea is you should not be servicing electronics. By describing what
you tried as a repair, if the monitor had turned on it would have caused
a fire and/or electrical shock hazard.
The stickers on the back that state "For service by authorized
personnell" or something similar refers to someone who will try to do
some basic troubleshooting before replacing a fuse and who will NEVER
use a fuse rated higher than required by the manufacturer.
The fuse is the first line of defense against a fire and almost never
opens unless there is an overload or short-circuit later on in the device.

muncey:
Generally, whan a fuse blows in a monitor, it means that there is a
short on the primary side of the switching power supply.
The power supply is designed so that it can detect an over-voltage or
over-current (short) on the secondary side (load side) and
automatically
shut down.
I would check the bridge rectifier (or 4 individual rectifier diodes)
and
the switching FET (on the heat sink) for shorts. Once in a while, a
capacitor
will short, but it is somewhat rare.
Hope this helps....
John