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KLV-32HX550,42HX650(CH)

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These servicing instructions are for use by qualified service personnel only.

To reduce the risk of electric shock, do not perform any servicing other than that contained in the operating instructions unless you are qualified to do so.

An isolation transformer should be used during any service to avoid possible shock hazard, because of live chassis.

The chassis of this receiver is directly connected to the ac power line.

Be sure to follow these guidelines to protect your property and avoid causing serious injury.

• Carry the TV with an adequate number of people; larger size TVs require two or more people.

• Correct hand placement while carrying the TV is very important for safety and to avoid damages.

Components identified by shading and ! mark on the schematic diagrams, exploded views, and in the parts list are critical for safe operation. Replace these components with Sony 

parts whose part numbers appear as shown in this manual or in supplements published by Sony. Circuit adjustments that are critical for safe operation are identified in this manual. 

Follow these procedures whenever critical components are replaced or improper operation is suspected.

KLV-32HX550,42HX650(CH)

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When repairing the LCD panel, be sure you are grounded by using a wrist band.

When repairing the LCD panel on the wall, the LCD panel must be secured using the 4 mounting holes on the rear cover.

1)

Do not press on the panel or frame edge to avoid the risk of electric shock.

2)

Do not scratch or press on the panel with any sharp objects.

3)

Do not leave the module in high temperatures or in areas of high humidity for an extended period of time.

4)

Do not expose the LCD panel to direct sunlight.

5)

Avoid contact with water. It may cause a short circuit within the module.

6)

Disconnect the AC power when replacing the backlight (CCFL) or inverter circuit. (High voltage occurs at the inverter circuit at 650Vrms.)

7)

Always clean the LCD panel with a soft cloth material.

8)

Use care when handling the wires or connectors of the inverter circuit. Damaging the wires may cause a short.

9)

Protect the panel from ESD to avoid damaging the electronic circuit (C-MOS).

10)

It is recommended not to exceed 1 hour of Power-On nor Burn-in period with LCD panel face down condition, in repair activity. 

KLV-32HX550,42HX650(CH)

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After correcting the original service problem, perform the following safety checks before releasing the set to the customer:

1. Check the area of your repair for unsoldered or poorly soldered connections. Check the entire board surface for solder splashes and bridges.

2. Check the interboard wiring to ensure that no wires are “pinched” or touching high-wattage resistors.

3. Check that all control knobs, shields, covers, ground straps, and mounting hardware have been replaced. Be absolutely certain that you have replaced all the insulators.

4. Look for unauthorized replacement parts, particularly transistors, that were installed during a previous repair. Point them out to the customer and recommend their replacement.

5. Look for parts which, though functioning, show obvious signs of deterioration. Point them out to the customer and recommend their replacement.

6. Check the line cords for cracks and abrasion. Recommend the replacement of any such line cord to the customer.

7. Check the antenna terminals, metal trim, “metallized” knobs, screws, and all other exposed metal parts for AC leakage. Check leakage as described below.

8. For safety reasons, repairing the Power board and/or Inverter board is prohibited.

KLV-32HX550,42HX650(CH)

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Leakage Test
The AC leakage from any exposed metal part to earth ground and from all exposed metal parts to any exposed 
metal part having a return to chassis, must not exceed 0.5 mA (500 microamperes).
Leakage current can be measured by any one of three methods.

1. A commercial leakage tester, such as the Simpson 229 or RCA WT-540A. Follow the manufacturers’

instructions to use these instructions.

2. A battery-operated AC milliampmeter. The Data Precision 245 digital multimeter is suitable for this job.

3. Measuring the voltage drop across a resistor by means of a VOM or battery-operated AC voltmeter. The 

“limit” indication is 0.75 V, so analog meters must have an accurate low voltage scale.
The Simpson’s 250 and Sanwa SH-63TRD are examples of passive VOMs that are suitable. Nearly all
battery-operated digital multimeters that have a 2 VAC range are suitable (see Figure A).

How to Find a Good Earth Ground
A cold-water pipe is a guaranteed earth ground; the cover-plate retaining screw on most AC outlet boxes is also 
at earth ground.
If the retaining screw is to be used as your earth ground, verify that it is at ground by measuring the resistance 
between it and a cold-water pipe with an ohmmeter. The reading should be zero ohms.
If a cold-water pipe is not accessible, connect a 60- to 100-watt trouble- light (not a neon lamp) between the hot 
side of the receptacle and the retaining screw. Try both slots, if necessary, to locate the hot side on the line; the 
lamp should light at normal brilliance if the screw is at ground potential (see Figure B).