Panasonic CT-25G6E Service Manual

Also see for CT27G6DE - 27" COLOR TV: Operating instructions Service manual

Panasonic CT-25G6E Service Manual Manual pdf 5 page image

- 5 -IMPORTANT: To protect against possible damage tothe solid state devices due to arcing or staticdischarge, make certain that all ground wires and CRTDAG wire are securely connected.CAUTION: The power supply circuit is above earthground and the chassis cannot be polarized. Use anisolation transformer when servicing the Receiver toavoid damage to the test equipment or to the chassis.Connect the test equipment to the proper ground ( ) or( ) when servicing, or incorrect voltages will bemeasured.WARNING: This Receiver has been designed to meetor exceed applicable safety and X-ray radiationprotection as specified by government agencies andindependent testing laboratories.To maintain original product safety design standardsrelative to X-ray radiation and shock and fire hazard,parts indicated with the symbol on the schematicmust be replaced with identical parts. Order parts fromthe manufacturer’s parts center using the partsnumbers shown in this service manual, or provide thechassis number and the part reference number.For optimum performance and reliability, all other partsshould be replaced with components of identicalspecification.X-Ray Protection Circuit Check &AdjustmentsThis test must be performed as final check before theReceiver is returned to the customer. If voltages areout of tolerance, immediate service and correction isrequired to insure safe operation and to prevent thepossibility of premature component failure.Equipment:1. Isolation transformer.2. High voltage meter.3. Short jumper.4. Jumper diode (same as D823, PN S3L60P154004).Diode should be rated a minimum of 150V.Procedure:1. Connect the Receiver to an isolation transformer.Turn Receiver ON.2. Apply a monoscope pattern.3. In Service Mode (see Service Mode Section in thismanual) select register Cb.4. Measure TP5 (located near the tuner). Comparethe measured value to the left column of the tablebelow. Set Cb with value from the right columncorresponding to the measured level at TP5.Example, if the measured level at TP5 is 1.03V, setCb to 03.5. Exit Service Mode and shut it OFF.6. Connect the short jumper between TPD16 andTPD17.7. Connect the jumper diode between TPD14 andTPD15 (cathode connected to TPD14, anodeconnected to TPD15, See Fig. 4 for locations).8. Apply 75VAC to the input of the isolationtransformer.9. Turn Receiver ON.10. Set PICTURE and BRIGHTNESS to minimum.11. Slowly increase the voltage at the input of theisolation transformer and confirm HHS voltagemeasure 35.0KV for 25” models, 35.8KV for 27”models using SAMSUNG CRT or 35.0KV for 27”models using AMEC CRT when the Receiver startsto go out of sync.12. Turn Receiver OFF and remove jumper & diode.TP5 MEASUREMENT SET Cb TO (HEX)0 ~ 0.93V 000.93 ~ 0.97V 010.97 ~ 1.01V 021.01 ~ 1.05V 031.05 ~ 1.09V 041.09 ~ 1.13V 051.13 ~ 1.17V 061.17 ~ 1.21V 07