DOWNLOAD Sony KLV-26HG2 (serv.man3) Service Manual ↓ Size: 8.61 MB | Pages: 83 in PDF or view online for FREE

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 B+ and HV to see if they are specifi ed values. Make sure 

your instruments are accurate; be suspicious of your HV meter if 
sets always have low HV.

8.  Check the antenna terminals, metal trim, “metallized” knobs, screws, 

and all other exposed metal parts for AC leakage. Check leakage as 
described below.

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 manµFacturers’ 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).

µ

1.5 k

Ω

g

AC Outlet Box

Ohmmeter

Cold-water Pipe

Figure A. Using an AC voltmeter to check AC leakage.

Figure B. Checking for earth ground.

 

 Four screws

    (+PSW 4x16) 

 

 Stand assy

 Rear cover

 

 Two screws

    (+BVTP 3x10) 

 Four screws

    (+PSW 4x8) 

 

 Cabinet assy

3

1

2

3

1

2

 Four screws

    (+PSW 4x10) 

 

 Four screws

    (+BVTT 3x6) 

 

 MS shield

 

 MSB board 

 

 VESA frame & bracket 

 

 MSB board 

 

 Two screws

    (+BVTT 3x6) 

 

 U1 board 

 Two screws

    (+BVTT 3x6) 

4

1

2

3

1

2

5

6

7

 

 G1 board 

 Five screws

    (+BVTT 3x6) 

 

 TU board 

 

 UD shield case

 

 UD board 

 

 A1 board 

 Two screws

    (+BVTT 3x6) 

 

 Two connector screws

 

 Two screws

    (+BVTP 3x8) 

 

 Four screws

    (+BVTT 3x6) 

4

1

2

3

1

2

6

5

7

8