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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 B+ and HV to see if they are speciÞ 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 manufacturers’ instructions to use these 
instructions.

2.    A battery-operated AC milliammeter. 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).

Parts on Set

0.15 µF

1.5 K 

Ω

AC

Voltmeter

(0.75 V)

Earth Ground

 

Remove (4) Screws (+BVTP 4 x 16)

 

Release top claws - Insert the tip of a ß athead 

screwdriver approximately 0.25" to unlock the 
claw. Gently lift up and then back to remove 
the cabinet.

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2

1

 

Gently wiggle the A board back and forth  to unplug 

it from the Neck Assembly.

 

Remove all necessary connections and rotate the 

D Board and rest it on its side to expose the bottom.  
Be sure to reconnect all wires.

 

Fabricate a temporary ground wire with a male 

stakon connector on one end and an alligator clip 
on the other.

 

Reconnect ground as shown below.

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4

 

Remove (1) screw (+BVTP 3 x 8) from the cable holder 

at the rear of the chassis base to release the cable. 

 

Remove (2) screws (+BVTP 3 x 8) from the rear of the D 

Board and remove the rear of the chassis base.

 

Remove remaining (7) screws (+BVTP 3 x 8) from the D 

Board.  Lift the board up and out to remove.

 

Remove the shield cover from the A board.

 

Gently wiggle the A board back and forth, and pull it to 

remove.

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5

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a

b

Anode Button

c

WARNING: High voltage remains in the CRT even after the power is disconnected. To avoid electric shock, discharge CRT before attempting to remove 
the anode cap.   Short between anode and coated earth ground strap of CRT.
NOTE: After removing the anode cap, short circuit the anode of the picture tube and the anode cap to either the metal chassis, CRT shield, or carbon 
painted on the CRT. 

1.  Do not use sharp objects which may cause damage to the surface of the 

anode cap. 

2.  To avoid damaging the anode cap, do not squeeze the rubber covering too 

hard. A material Þ tting called a shatter-hook terminal is built into the rubber. 

3.  Do not force turn the foot of the rubber cover. This may cause the shatter-hook 

terminal to protrude and damage the rubber.

Turn up one side of the rubber cap in the 
direction indicated by arrow  a .

Use your thumb to pull the rubber
cap Þ rmly in the direction indicated
by arrow   b .

When one side of the rubber cap separates from 
the anode button, the anode cap can be removed 
by turning the rubber cap and pulling it in the 
direction of arrow   c .

 

Place the unit face down on a cushion to avoid 

scratching.

 

Remove the anode cap.

 

Remove (4) screws (Screw (5) Tapping) from 

the CRT.

  

Remove 

the 

A 

board.

 

Remove the neck assembly.

 

Remove the deß ection yoke.

 

Remove (2) screws (BVTP 4 x 16) from the 

base assembly and slide out to remove.

 

Remove the demagnetization coil.

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