Philips DPTV400 Series, Training Manual

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ing, check for Vertical and Horizontal drive to the LSB from the SSM. Vertical drive can be checked
with an oscilloscope on Pins 3 and 4 of connector 1510 on the LSB. Horizontal drive can be
checked on Pin 9 of 1510. If the G2 voltage is missing, and Horizontal and Vertical drive is present,
the LSB should be repaired or replaced.
Once G2 has been verified, check the Filament voltage on Pin 3 of connector 1202 on the LSB.
This voltage should be approximately 6 volts DC. The G1 voltage on Pin 4 of 1202 should be
approximately minus 20 volts. If this voltage is a minus 200 volts, the CRTs are being blanked,
indicating a problem with the LSB.
Audio problems
Audio from AV3, AV4 and AV5 on the HD-DW module is fed to the SSM on connector 1753 on the
SSM. Selected AV audio is fed to the ATSC module on Pins 7 and 8 of 1751 on the SSM. Tuner
audio is processed on the ATSC module. The audio processor on the ATSC module selects
between the AV audio from the SSM or the Tuner audio on the ATSC module. Selected audio is
then fed to the SSM on Pins 3 and 4 of 1751. The audio is then fed to the SSB via the SSM for
additional processing. The input to the SSB can be checked on Pins 53 and 58 of connector 1420.
Volume control, muting, balance, along with other functions are controlled by the audio processor on
the SSB. The output of the SSB can be checked on Pins 75 and 76 of connector 1420. The power
supplies for the Audio Amplifier can be checked on Pins 10 and 11 of connector 1516 on the SSM.
This should be a minus and plus 19 volts. Output from the Audio Amplifier can be checked on Pins
1 and 5 of connector 1349 on the SSM. In the HD and Epic versions, the speakers are connected
to 1349. In the Epic Plus version, it is connected to a Center Channel speaker switch.
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