REPAIRING AND NOT THROWING AWAY

REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

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Tuesday 26 February 2019

HOW TO ENTER SERVICE MODE TO PHILIPS PROJECTION TV PHILIPS - PTV - 800_805_810_811_815_820_825

HOW TO ENTER SERVICE MODE TO PHILIPS [PTVs]


HOW TO ENTER SERVICE MODE TO PHILIPS [PTV SERES] TVs


PHILIPS; PTV800_PTV805_PTV810_PTV811_PTV815_PTV820_PTV825 _ SERVICE ADJUSTMENTS.
                                                                    
  • All service adjustment to this chassis are hot voltage wise, So ensure the use of properly insulated tools.
TUNER ADJUSTMENT
  • Turn the set ON, and tune to an on-air station.
  • Connect digital voltmeter to [TP-41] on the small signal panel.
  • Adjust (C341) [Zone E-6] to obtain a reading of 2.5VDC on the meter.
  • This adjustment may effect on-screen menu positioning  as well as other graphics generated set.
RF AGC DELAY
  • Single tuner models. [ASG051 & ASG052]. The adjustment control [R202] can be located on the small signal panel in zone area J2.

  1. Tune to a weak station.
  2. Set R202 to its fully counterclockwise position.
  3. Slowly advance it to a point slightly beyond the point of minimum noise in picture.
  • Two tuner models. [ASG053 & ASG054]. Control resistor [R256] can be located on the small signal panel zone area K5  Use the adjustment procedure as described above, to this adjustment too.
  • Do not advance the control any further, as it may result in an overloaded picture.  The range of the AGC voltage supplied to pin [9] of the Varactor tuner may vary from 4.2VDC without signal, and 1.87VDC with signal.
VCO AND AFT ADJUSTMENT.
Single tuner models.
  1. Cut the shield break point around IC200, and the IF circuitry.  Peel the top cover of the shield to gain access to internal circuitry.
  2. Short test points 16A&16B of the varactor tuner module.
  3. Short test point [23] to ground.
  4. Connect DC voltmeter to test point [7].
  5. Turn the set ON, and record the voltage reading from test point [7].  Typically 4.5V to 5.0VDC.
  6. Turn OFF the set, and remove both shorts from test points TP16A/B and TP23.
  7. Connect the coincidence line at the collector of [Q207] to +5V DC line on the tuner.
  8.  Apply local broadcast signal, preferably on-air signal, to antenna terminals and turn the set ON.
  9. Select the cable tuning from the menu item, select channel 36 or other high band inactive cable channel.
  10. While still in cable mode, select local VHF broadcast channel.  The tuning system will attempt to tune three times and then lock on to the FCC assigned frequency.
  11. Adjust AFT coil [L202] to obtain a reading of +7.5VDC at test point [tp2].
  12. Adjust VCO coil [L204] to obtain the same DC voltage that was noted above.
  13. Remove the jumper wire from coincidence line.
  14. Verify the adjustment by changing between by High Band and local VHF broadcast channel, and ensure that the local broadcast channels lock in quickly.
Two tuner models.
  1. Cut the shield break points around IC201 and IF circuitry.  Peel back the top cover of the shield to gain access to the internal circuitry.
  2. Short test points [16C&D] of the varactor tuner module .
  3. Short test point [23A], pin 13 of IC201, to ground..
  4. Connect DC voltmeter to test point [7A].
  5. Turn the set ON and record the voltage reading from test point [7A]; typically 4.5 to 5.0VDC.
  6. Turn OFF the set and remove shorts from test points [TP16C,D&23A].
  7. Connect the coincidence line at the collector of Q207, to 5VDC line on the tuner.
  8. Apply local broadcast signal by the antenna terminal, and turn ON the set.
  9. Select the Cable Tuning from menu options,and select channes 36 or some other high band inactive cable channel.
  10. While still in cable mode, select local VHF broadcast channel. The tuning system will attempt to tune three times, and then lock on to the FCC assigned frequency.
  11. Adjust the AFT coil [L219] to obtain a reading of +6.6VDC, at test point [TP2A].
  12. Adjust the VCO coil [L220] to obtain the same DC voltage reading at test point [TP7A] that was noted in step 5 of this adjustment procedure.
  13. Remove the jumper from the coincidence line.
  14. Verify this adjustment by changing between the high-band and local VHF broadcast channel and ensure that local broadcast channels locks in quickly.

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.
Posted By: FRANK at 04:00
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