Magnum PF21500, Service Manual

1. 

SAFETY INSTRUCTIONS AND MAINTENANCE 

WARNING: 

BEFORE SERVICING THIS CHASSIS, READ THE “X-RAY RADIATION 

PRECAUTION”, “SAFETY  PRECAUTION”AND “PRODUCT SAFETY 

NOTICE”INSTRUCTION BELOW. 

1.1 X-RAY RADIATION PRECAUTION 

1.1.1 

The EHT must be checked every time the TV is serviced to ensure that the CRT does not emit X-ray 

radiation as result of excessive EHT voltage. The maximum EHT voltage permissible in any operating 

circumstances must not exceed the rated value. When checking the EHT, use the High Voltage Check 

procedure in this manual using an accurate EHT voltmeter. 

1.1.2 

The only source of X-RAY radiation in this TV is the CRT. The TV minimizes X-RAY radiation, which 

ensures safety during normal operation. To prevent X-ray radiation, the replacement CRT must be identical to 

the original fitted as specified in the parts list. 

1.1.3 

Some components used in this TV have safety related characteristics preventing the CRT from emitting 

X-ray radiation. For continued safety, replacement component should be made after referring the PRODUCT 

SAFETY NOTICE below. 

1.1.4 

Service and adjustment of the TV may result in changes in the nominal EHT voltage of the CRT anode. 

So ensure that the maximum EHT voltage does not exceed the rated value after service and adjustment. 

1.2 SAFETY PRECAUTION 

WARNING: 

REFER SERVICING TO QUALIFIED SERVICE PERSONNEL ONLY. 

1.2.1 

The TV has a nominal working EHT voltage. Extreme caution should be exercised when working on the 

TV with the back removed. 

Do not attempt to service this TV if you are not conversant with the precautions and procedures for 

working on high voltage equipment. 

When handling or working on the CRT, always discharge the anode to the TV chassis before removing the 

anode cap in case of electric shock. 

The CRT, if broken, will violently expel glass fragments. Use shatterproof goggles and take extreme care 

while handling. 

Do not hold the CRT by the neck as this is a very dangerous practice.. 

1.2.2 

It is essential that to maintain the safety of the customer all power cord forms be replaced exactly as 

supplied from factory. 

1.2.3 

Voltage exists between the hot and cold ground when the TV is in operation. Install a suitable isolating 

transformer of beyond rated overall power when servicing or connecting any test equipment for the sake of 

safety. 

1.2.4 

When replacing ICs, use specific tools or a static-proof electric iron with small power (below 3 5W). 

1.2.5 

Do not use a magnetized screwdriver when tightening or loosing the deflection yoke assembly to avoid 

electronic gun magnetized and decrement in convergence of the CRT.   

1.2.6 

When remounting the TV chassis, ensure that all guard devices, such as nonmetal control buttons, switch, 

insulating sleeve, shielding cover, isolating resistors and capacitors, are installed on the original place. 

1.2.7 

Replace blown fuses within the TV with the fuse specified in the parts list. 

1.2.8 

When replacing wires or components to terminals or tags, wind the leads around the terminal before 

soldering. When replacing safety components identified by the international hazard symbols on the 

circuit diagram and parts list, it must be the company-approved type and must be mounted as the original. 

1.2.9 

Keep wires away from high temperature components. 

1.3 PRODUCT SAFETY NOTICE 

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