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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 specified 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.

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).

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).

µF

1.5 k

Ω

Trouble Light

AC Outlet Box

Ohmmeter

Cold-water Pipe

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

Figure B. Checking for earth ground.

3 times

2 times

4 times

5 times
9 times

10 times

LED ON 0.3 sec.

LED OFF 0.3 sec.

LED OFF

3 sec.

 

+B Overcurrent 

 

2 times

 

+B Overvoltage 

 

3 times

 

V-STOP   

 

4 times

 

IK (AKB)   

 

5 times

 

Zero Cross 

 

9 times

 

9V  

 

 

10 times

*One flash count is not used for self-diagnostic.

The units in this manual contain a self-diagnostic function. If an error occurs, the STANDBY/TIMER LED will automatically begin to flash. The number 

of times the LED flashes translates to a probable source of the problem. A definition of the STANDBY/TIMER LED flash indicators is listed in the 

instruction manual for the user’s knowledge and reference. If an error symptom cannot be reproduced, the Remote Commander can be used to review 

the failure occurrence data stored in memory to reveal past problems and how often these problems occur.

When an error occurs, the STANDBY/TIMER LED will flash a set number of times to indicate the possible cause of the problem. If there is more than 

one error, the LED will identify the first of the problem areas.

Results for all of the following diagnostic items are displayed on screen. If the screen displays a “0”, an error has occurred.

Power does not turn on  

Does not light 

�

  Power cord is not plugged in. 

�

  Fuse is burned out (F601). (GK Board) 

�

  Power does not come on. 

�

  No power is supplied to the TV. 

�

  AC Power supply is faulty. 

+B overcurrent (OCP)* 

2 times 

�

  H.OUT (Q502) is shorted. (A Board) 

�

  IC702 is shorted. (C Board) 

�

  Power does not come on. 

�

  Load on power line shorted. 

+B overvoltage (OVP) 

3 times 

�

  IC501 is faulty. (A Board) 

�

  If a high is supplied to pin 2 of IC501. 

(A Board) 

�

  Has entered standby mode. 

V-Stop 

4 times 

�

  +12V is not supplied. (A Board) 

�

  IC561 is faulty. (A Board) 

�

  Has entered standby state after 

horizontal raster. 

�

  Vertical deflection pulse is stopped. 

�

  Power line is shorted or power 

supply is stopped. 

IK (AKB) 

5 times 

�

  Video OUT (IC561) is faulty. (A Board) 

�

  IC702 is faulty. (C Board) 

�

  Screen (G2) is improperly adjusted. ** 

�

  No raster is generated. 

�

  CRT Cathode current detection 

reference pulse output is small. 

Zero Cross 

9 times 

�

  No zero cross pulses on pin 45 

IC1001. (A Board) 

�

  Power does not come on. 

9V Check  

10 times 

�

  Relay failed (RY600) 

�

  Power does not come on. 

*  If a +B overcurrent is detected, stoppage of the vertical deflection is detected simultaneously. The symptom that is diagnosed first 

by the microcontroller is displayed on the screen. 

** Refer to Screen (G2) Adjustments in Section 2-4 of this manual 

Turn off the power switch on the TV main unit or unplug the power cord from the outlet to stop the STANDBY/TIMER LAMP from flashing.

For errors with symptoms such as “power sometimes shuts off” or “screen sometimes goes out” that cannot be confirmed, it is possible to bring up past 

occurrences of failure on the screen for confirmation.

In standby mode, press buttons on the Remote Commander sequentially, in rapid succession, as shown below:

DISPLAY     Channel  5    Sound volume  -     Power ON.

Numeral “0” means that no fault was detected.

Numeral “1” means a fault was detected one time only.

Since the diagnostic results displayed on the screen are not automatically cleared, always check the self-diagnostic screen during repairs. When you 

have completed the repairs, clear the result display to “0”.

Unless the result display is cleared to “0”, the self-diagnostic function will not be able to detect subsequent faults after completion of the repairs.

To clear the result display to “0”, press buttons on the Remote Commander sequentially when the diagnostic screen is displayed, as shown below:

 

ENTER

Channel 8

To quit the entire self-diagnostic screen, turn off the power switch on the Remote Commander or the main unit.

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+B overcurrent (OCP) 
Occurs when an overcurrent on the +B (135V) line is detected by pin 48 of IC001 (A Board). If the voltage of pin 48 of IC001 (A Board) is less than 1V 
when V.SYNC is more than seven verticals in a period, the unit will automatically turn off. 

+B over voltage (OVP) 
Occurs when a high is felt on pin 2 of IC501 (A Board).

V-STOP 
Occurs when an absence of the vertical defl ection pulse is detected by pin 31 of IC301 (A Board). Power supply will shut down when waveform interval 
exceeds 2 seconds. 

IK (AKB) 
If the RGB levels* do not balance within 2 seconds after the power is turned on, this error will be detected by IC301 (A Board). TV will stay on, but 
there will be no picture.

*(Refers to the RGB levels of the AKB detection Ref pulse that detects 1K).

Zero Cross
Check Q691 collector (GK Board) 7.5V STBY goes to 0V when the set is turned on. 

9V Check
Check Q691 collector (GK Board) 7.5V STBY goes to 0V when the set is turned on.