Panasonic PT-56HX41PF Service Manual

ORDER NO. MTNC021094A1 B2

Service Manual

HDTV MONITOR

Simplified Manual

(P7)

Panasonic

Models

PT-56HX41PF EP824

This simplified service manual is issued to ADD model of the P7 family listed above to the simplified service manual order No. MTNC020413A1 (PT-51HX42F). Included in this manual are unique characteristics and a differences parts list compared to PT-51HX42F. Please file and use this simplified service manual together with the simplified service manual order No MTNC020413A1 (PT-51HX42F) and the main service manual order No MTNC020411C1 (PT-47WX52F).

Chassis

“WARNING! This servicemanual is designedfor experienced repair techniciansonlyand is not designed for use by the general public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product. Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service or repair the product or products dealt with in this Service Manual by anyone else could result in serious injury or death.”

The service technician isrequiredtoreadand follow the “Safety Precautions”and“Important Safety Notice” in the Main Manual.

and distribution is a violation of law.

Important safety notice

Special components are used in this projection television which are important for safety. These components are identified on the schematic diagram by the symbol and printed in BOLD TYPE on the replacement part list. It is

essential that these critical parts are replaced with the manufacturer’s specified replacement part to prevent x-ray radiation, shock, fire or other hazards. Do not modify the original design without the manufacturer’s permission.

Safety precautions

General guidelines

isolation transformer

during the servicing of a PTV whose chassis is not isolated from AC power line. Use a transformer of adequate power rating as this protects the technician from accidents resulting in personal injury from electrical shocks. It will also protect the PTV from being damaged by accidental shorting that may occur during servicing. When servicing, observe the original lead dress, especially in the high voltage circuit. Replace all damaged parts (also parts that show signs of overheating.) Always replace protective devices,suchas fishpaper, isolation resistors and capacitors, and shields after servicing the PTV. Use only manufacturer’s recommended rating for fuses, circuits breakers, etc. High potentials, as high as 32.5kV, are present when this PTV is operating. Operation of the PTV without the rear cover introduces danger for electrical shock. Servicing should not be performed by anyone who is not thoroughly familiar with the necessary precautions when servicing high-voltage equipment.

Extreme care should be practiced when handling the

picture tube

due to atmospheric pressure. (14.7 lbs. per sq. in.). Do not nick or scratch the glass or subject it to any undue pressure. When handling, use safety goggles and heavy gloves for protection. Discharge the picture tube by shorting the anode to chassis ground (not to the cabinet or to other mounting hardware). When discharging connect cold ground (i.e. DAG ground lead) to the anode with a well insulated wire or use a grounding probe.

. Rough handling may cause it to implode

X-ray precautions

The front area (between the projection tube and the lens) is enclosed by a metal box to ensure positive safety during normal and abnormal conditions when checking and repairing. T o fully ensure safety, the following precautions must be observed.

1. Do not remove the lens or metal box.

2. Make sure to turn the power OFF when the lens is removed or when checking the cleanliness of the lens.

3. Do not remove the lens or metal box to check the projection tube for operation by watching it directly. Use a mirror or paper to view the image.

Before returning a serviced PTV to the owner,the service technician must thoroughly test the unit to ensure that is completely safe to operate. Do not use a

line isolation transformer when testing.

Leakage current cold check

Unplug the ACcord and connect a jumper between the two plug prongs. Press the POWER switch ON. Measure the resistance between the jumpered AC plug and expose metallic parts such as screw heads,

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should always be used

antenna terminals, control shafts, etc. If the exposed metallic part has a return path to the chassis, the reading should be between 240kΩ and 5.2MΩ. If the exposed metallic part does not have a return path to the chassis, the reading should be infinite.

Leakage current hot check (see figure 1)

Plug the AC cord directly into the AC outlet. Do not use an isolation transformer during the check. Connect a 1.5kΩ 10 watt resistor in parallel with a

0.15µF capacitor between and exposed metallic part and ground. Use earth ground, for example a water pipe. Using a DVM with a 1000 ohms/volt sensitivity or higher, measure the AC potential across the resistor. Repeat the procedure and measure the voltage present with all other expose metallic parts. Verify any potential does not exceed 0.75 volt RMS. A leakage current tester (such a Simpson model 229, Sencore model PR57 or equivalent) may be used in the above procedure, in which case any current measure must not exceed 0.5 milliamp. If any measurement is out of the specified limits, there is a possibility of a shock hazard and the PTV must be repaired and rechecked before it is returned to the customer.

AC VOLTMETER

COLD WATER PIPE (GROUND)

0.15µF

TO INSTRUMENT’S EXPOSED METAL PARTS

Figure 1. Hot check circuit

1500Ω,10W

Insulation test

Connect an insulation tester between an exposed metallic part and AC line. Apply 1080VAC/60Hz for 1 second. Confirm that the current measurement is 0.5mA ~ 2.0mA. Repeat test with other metallic exposed parts.

X-ray radiation

WARNING: The potential source of x-ray radiation in the

PTV is in the high voltage section and the picture tube.

Note: It is important to use calibrated equipment.

Apply all black video signals (1080i) and confirm high voltage measures 31.5 ± 1.0kV. If the high voltage is not within the range, change C514 to 1800pF, 2000pF, 2400pF or 2700pF until the desired value is obtained. Apply NTSC white pattern and confirm the high voltage measures 30.1 ± 1.5kV. Apply HD 1080I white pattern and confirm the high voltage measures 30.1 ± 1.5kV

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About lead free solder (PbF)

component

Note: Lead is listed as (Pb) in the periodic table of elements. In the information below, Pb will refer to Lead solder, and PbF will refer to Lead Free Solder. The Lead Free Solder used in our manufacturing process and discussed below is (Sn+Ag+Cu). That is Tin (Sn), Silver (Ag) and Copper (Cu) although other types are available.

This model uses Pb Free solder in it’s manufacture due to environmental conservation issues. For service and repair work, we’d suggest the use of Pb free solder as well, although Pb solder may be used.

PCBs manufactured using lead free solder will have the PbF within a leaf symbol stamped on the back of PCB.

Caution

• Pb free solder has a higher melting point than standard solder. Typically the melting point is 50 ~ 70 °F(30~40°C) higher. Please use a high temperature soldering iron and set it to 700 ± 20 °F(370± 10 °C).

• Pb free solder will tend to splash when heated too high (about 1100 °For600°C). If you must use Pb solder, please completely remove all of the Pb free solder on the pins or solder area before applying Pb solder .If this is not practical, be sure to heat the Pb free solder until it melts, before applying Pb solder.

• After applying PbF solder to double layered boards, please check the component side for excess solder which may flow onto the opposite side. (see figure below)

component

remove all of the

excess solder

slice view

solder

Suggested Pb free solder

There are several kinds of Pb free solder available for purchase. This product uses Sn+Ag+Cu (tin, silver, copper) solder. However, Sn+Cu (tin, copper), Sn+Zn+Bi (tin, zinc, bismuth) solder canalsobeused.

0.3mm X 100g

0.6mm X 100g 1.0mm X 100g

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Important safety tests

Measuring H.V.

The anode caps are cemented to the CRTs. To gain access for high voltage measurement, remove the red CRT’s anode lead from the flyback transformer distributor. Grasp the anode lead protective cap at its bottom and squeeze it against the locking cap body inside, rotate 1/4 turn counter clockwise and pull the anode lead sleeve out of the FBT distributor. Connect a high voltage lead (+) from your H.V. meter to the FBT

distributor, and the common (-) to cold ground ( ). (see figure 2).

Grasp protective

Anode lead

rubber cap

Push & rotate

Discharge to CRT chassis

cap counterclockwise to remove

FBT distributor

Figure 2. Removal of FBT leads

Note: Reinsert the anode lead into the FBT

distributor until it is tightly and fully seated. Turn the locking cap clockwise to lock in place.

(EHT) Protector operation check

With the cabinet back removed, apply a nominal 120V AC to the PTV.

Over voltage test Preparation:

1. Turn PTV “OFF”

2. Connect a NTSC signal generator to the antenna terminal.

3. Connect DVM (+) TPD50 and (-) TPD51 on D Board (see figure 4)

4. Connect a H.V. meter (static type, class 0.1) with high voltage leads to high voltage distributor on FBT. (See figure 4)

TPD51 TPD50

D-Board

DVM

Variable power supply

MA150

100Ω 1/2 W

(+)

(15~25DC)

(-)

D-BOARD

IC802 PIN 2

OR TPD8

HEAT SINK OF Q551

Figure 4. DVM & power supply connection.

5. Connect the 15 ~25 VDC variable power supply to (+) TPD8 or IC802 pin 2 (D-Board) and (-) heat sink of Q551 (see figure 4).

Procedures:

1. Apply a NTSC white pattern.

2. Turn PTV ON.

3. Adjust the picture or brightness controls so that the DVM reads 16.5±0.5 Volts.

4. Increase the variable power supply until set turns off. The set should turn off at 16.5±0.5 Volts (DVM) and high voltage less than 36.4kV.

5. If the DVM reading i s other than 16.5±0.5 Volts, readjust picture or brightness control and repeat steps 3.

6. Turn off the variable supply and confirm that the set will turn on with the remote control.

H.V. METER

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Cold ground

FBT Distributor

CRT

CHASSIS

Figure 3.Measuring H.V.

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Notes about format aspect switching

(WX 16:9 or HX 4:3) and adjustments

Widescreen 16:9 and non-widescreen 4:3 PTVs use the same light box, for this reason is important to set it to the correct version (16:9 or 4:3). To change the format please refer to figure 5 on page 6 on this simplified service manual. Be sure to select the correct format for the serviced PTV.

Adjustments for NTSC ZOOM included in main manual order No MTNC020411C1 does not apply for model included in this simplified service manual.

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