Thursday, June 14, 2012

HOW TO ENTER SERVICE MODE TO PHILIPS [PTVs]



PHILIPS - PTV - 800_805_810_811_815_820_825 - ALIGNMENT PROCEEDINGS.
PART-2
+130VDC - B+ ADJUSTMENT
The adjustment control can be located at the large signal panel in zone area [A-6]; is (R455).  Upon replacement of large signal panel. of if suspect of possible problems with +130VDC arise, check and adjust.
  • Connect the +ve lead of digital voltmeter to +130VDC [TP-4].
  • Connect the -Ve lead to isolated ground.
  • Adjust [R455], so that the voltmeter reades +130VDC.
HIGH-VOLTAGE ADJUSTMENT
To do this, a High Voltage Probe and digital volt meter is necessary.
INITIAL PTV SETTINGS
  • Turn the TV ON.
  • Confirm that the 130VDC is OK.
  • Select a Non-Aux input for black picture.
  • Turn the TV Off.
  1. Connect the ground lead of voltmeter to chassis Ground.
  2. Connect the High-voltage probe to meter.
  3. Set the digital multimeter to measure DC volts.
  4. Remove one of CRT anode connections from High-Voltage splitter. Make sure that [R943] is turned fully clockwise.
  5. Insert the probe tip into the CRT anode connection of the High-voltage splitter.
  6. Turn the PTV ON.
  7. Adjust [R943], High_Voltage _adjust, on the large signal panel  [zone H2] for 30Kv.
  8. Turn OFF the PTV.
  9. Remove the High-Voltage probe.
  10. Re-install CRT anode connector into the combo block.
  11. Turn the PTV On, and confirm proper operation.
PROGRAMMING FACTORY DEFAULT VALUES
Service Mode Entry and Exit.
  • Using the remote control, enter digits [0-6-2-5-9-6 > Menu].
  • Depressing the Power button on the front panel of the TV, will Exit the Service Mode, and save the current modifications, and turn the chassis OFF.
There are 81 registers within the system.  Some of the data held in these registers should not be altered and others which are factory set and uneque to unit under test.  It is highly recommended that the current values held in these registers be recorded.  This procedure could save a significant amount of time, should a mistake occur causing an undesirable condition to the unit under test.
DESCRIPTION OF SERVICE MODE
This service mode is used for changing service control register values from their default values to new values.  When entering this service mode, the tuning system will attempt to receive the current register values that are stored in the EEPROM.  If the EEPROM has never been programmed, default data values will be stored.
Depression of the PWR button on the front panel of the TV while in this mode, or, setting register 00 to "00", shall cause the tuning system to write the adjusted values to the EEPROM IC before chassis power is turned OFF.
ADJUSTMENT OF REGISTERS IN SERVICE MODE
When the receiver is operating in the service mode, all normal on-screen displays are suppressed and replaced by special display.  This display has two lines of information at the bottom of the screen.  The first line of text shows the factory part number of the microcomputer.  The next set of characters denotes the version of the software currently operating.  The second line starting from left, has currently tuned channel. Channel 3 is the default when entering the service mode setup as most signal generators output comes at channel 3.  If no signal is available on this channel, pressing the channel Up/Dn button will allow  to select an active channel.
  • The Cursor Left/Right keys are used to select among the channel, register and data held in that register.
  • The Cursor Up/Dn keys allow the data value to selected items to alter.