VTL S-400 II series Owner's Manual page 57

2. When I try to power on the unit with either the remote control or the front panel, the Display Window shows
blinking numbers such as 120 or 240. What is the problem?
Check to make sure that the amplifier's voltage setting matches with your AC line voltage. Locate the
AC Voltage test button hidden behind the Diagnostic cover on the Front Panel and press that button.
The Display Window will display the AC voltage setting of the amplifier (as preset by the factory.) If you hold
this button for more than 5 seconds, the Display Window will show the incoming AC voltage from your AC
.
line
If your amplifier's AC voltage setting matches with the line AC voltage but the problem still persists,
then contact your authorized VTL dealer or the VTL factory.
3. I am getting a noise and hum coming from my speakers when I turn the amplifiers on. What can I do to
eliminate the noise?
It is recommended that you connect your audio components as possible to a good clean AC ground in
your system, and for quietest operation it is recommended that all components be plugged into the same
ground potential (or same AC outlet.) In single ended mode a ground loop hum can result from a
difference in ground potential between different components in the system and it is recommended that
the system be operated in the balanced mode to defeat ground loop problems. Under no circumstances
should you attempt to defeat the ground with a ground lifter cheater plug, as serious damage to the
componets and yourself could result. If the noise persists you should either contact your dealer or the
VTL factory to try to resolve this problem.
4. I am getting a noise and hum coming from my system when I plug in a video source. What can I do to
eliminate the noise?
The noise may be coming in from your video cable system. First disconnect the VCR from the system
to see if this will solve the problem. If it does then you will need to try to lift the ground from the cable
TV wire by means of a cable ground-lifting transformer available from most electronics stores. If the
problem still persists contact your VTL authorized dealer or the VTL factory service department.
5. I am getting a ringing noise from the amplifier when I touch or bump it. What should I do?
One or more of the tubes in the amplifier may be microphonic and the source of the problem. Follow
the procedures listed in this manual to remove the tubes and change them for new ones.
6. When I try to power the amplifier up I get a POWER fault shutdown, or I get power up, but no output.
What is the problem?
One or both of the rail fuses might be blown for some reason, which can happen when there is
a power surge or when an output tube fails, as sometimes the fuse blows before the fault sensing
can complete the amplifier shutdown. Check the fuses in the rear panel Fuse tester, and replace
the blown one and try to re-power. If the problem persists then contact your authorized VTL
dealer or the factory.
7. I cannot clear the POWER fault light, and the amplifier won't let me power it up. What is the problem?
If RS-232 control is attached to the amplifier try checking the message displayed. If it says Over
Voltage fault then the amplifier has an internal power supply fault in the regulator, which cannot
S-400 Amplifier Owner's Manual
VTL
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