Fender Bassman 100T Instrucciones De Funcionamiento página 9

The Bassman® 100T uses the following types of tubes:
Pre-Amplifier: Two 12AX7A tubes (V1, V2).
Power Amplifier: One 12AT7 tube (V3) and Four 6L6GC power tubes
(V4, V5, V6, and V7).
(Chassis, bottom view)
If your amplifier is not performing as it should, refer to the
Troubleshooting section below. Generally speaking with most tube
audio amplifers the tubes are the most likely thing to fail and may
be replaced without taking your amplifier to a qualified service
technician. If any tubes need replacing, carefully read and follow
these steps. If you do not feel comfortable replacing your amplifier's
tubes, take it to an authorized Fender service center. All other service
needs should be refered to an authorized Fender service center.
There are no user serviceable parts inside the electronics chassis.
Lethal voltages exist inside your tube amplifier! Tube amplifier
components get very hot! Failure to follow all these instructions may
result in damage to your amplifier, or personal injury!
How to Replace the Tubes on your amplifier:
1) If Fender Automatic Bias indicated a tube failure, make a note of
which tube(s) failed. NOTE: Bad tubes will remain displayed as
bad until they are replaced, even if the power is cycled on/off.
2) Turn off the amplifier and remove the power cable from the IEC
inlet {O}. You might also want to disconnect other cables (such
as the speaker, line-out, effects loop, etc) so that they are not in
the way.
3) Caution! The tubes and transformers get very hot during
operation, and may cause burn injuries. Wait for the amplifier to
cool down before proceeding to step 4.
4) After the amplifier has cooled, use a #2 Phillps screw-driver to
remove the four screws that secure the wooden back panel &
metal cage to the cabinet. There are two screws at each end. The
two large screws in the middle do not need to be removed.
5) With the rear cover removed, you now have access to all of
the tubes and tube fuses. Pre-amp tubes have metal shields
that must be twisted and pulled down to remove them. The
power amplifier tubes have spring-retainer clips that must be
held upwards (pressed toward chassis surface) to remove the
tubes. Pull the tubes straight down to remove them and avoid
rocking them side-to-side to prevent breakage. They should
be somewhat difficult to remove. Caution: Excessive side-
to-side motion could cause the Locator-Pin on the bottom of
Tube Replacement Tube Replacement
Front face of chassis
Fuses
fender.com
the tube to fracture in the socket, which will not be covered
by the Fender Electronic Product Warranty to remove. If you
are uncomfortable in performing this process please seek the
assistance of an Authorized Fender Electronics Service Center.
6) Refer to the tube chart
for tube type and
location. Fuse holders
are marked to indicate
the corresponding tube
pairs.
7) Replace faulty tubes
with tubes of the same type. Refer to the note below about
proper tube handling methods. NOTE: It is not necessary to
replace output tubes with matched sets of the same grade. Any
output tube of the same type (6L6) will work.
8) Replace all the necessary fuses. NOTE: The type of fuses used
for the tubes can be blown without showing any visible signs of
failure. If Fender Automatic Bias indicated that a tube and fuse
have failed, you should replace the fuse, even if it looks okay.
9) Replace the rear cover of the amplifier and install all four
mounting screws.
10) Reconnect the speaker cable and any other signal cables you
disconnected in step 2.
11) Reconnect the power cable.
12) Turn on the amplifier, but keep it in standby for at least 1 minute.
13) Press & hold the up/down adjust buttons for 2 seconds to reset
the Automatic Bias settings.
14) Take the amplifier out of standby and wait for the Fender
Automatic Bias display to update (10-15 seconds). If the display
still indicates that the tubes are bad, either the fuse or tubes
used as replacements were not good. Repeat steps 1 – 14, with
new tubes or fuses.
Note on Handling Tubes:
It is important not to leave fingerprints,
grease, or other foreign substances on the
glass surface of the tubes. This is especially
important for the power output tubes. If
fingerprints or other substances are left on
the surface of the tube, they will cause the
tube to become hotter than normal in that
spot, which can lead to cracks in the glass
and premature failure of the tube. Some
people recommend not touching the tubes with bare hands at all.
However, it this is usually impossible to avoid. Take the following
steps to ensure that the tubes are clean and will have the maximum
possible life:
1) Wash your hands before handling the tubes.
2) Avoid excess handling of the tubes.
3) After installation of the tubes, wipe them with a clean cloth to
remove any fingerprints or foreign substances.
POWER FAN
TRANSFORMER
POWER
TRANSFORMER
0091052000
SOAK
V2
V1
12AX7A
12AX7A
CHOKE
0036486000 V7 V6 V5 V4
V3
6L6GC 6L6GC 6L6GC 6L6GC 12AT7
2A 1A 1B 2B
TUBE
FUSES
OUTPUT
0091053000
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