SONY KV-21FA310 - KV-24FS120 - KV-25FS120 SERVICE MODE POWER LED BLINKING CODE AND CIRCUIT DIGRAM

SONY KV-21FA310 - KV-24FS120 - KV-25FS120 

SERVICE MODE POWER LED BLINKING CODE AND CIRCUIT DIGRAM 

SELF DIAGNOSIS 
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.
Diagnostic Test Indicators
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. No error has occurred if the screen displays a “0”.
POWER LED BLINKING CODE 
Diagnostic Item Description



No. of times
STANDBY/ TIMER
lamp flashes

Probable Cause Location



Detected Symptoms



Power does not turn on



Does not light



Power cord is not plugged in.
Fuse is burned out (F601). (A 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 (Q506) is shorted. (A Board)
(20”/21” models only)
H.OUT (Q505) is shorted. (A Board)
(24”/25” models only)
•RGB Amp (IC1751) is shorted.
(CV Board)

Power does not come on.
 Load on power line is shorted.






I-Prot




4 times




+13V is not supplied. (A Board)
IC545 is faulty. (A Board)



 Has entered standby state after horizontal raster.
 Vertical defl ection pulse is stopped.
 Power line is shorted or power supply is stopped.



IK (AKB)



5 times



 Video OUT (IC545) is faulty.
(A Board)
 IC001 is faulty. (A Board)
 Screen (G2) is improperly adjusted.**


No raster is generated.
 CRT Cathode current detection reference pulse
output is small.

If a +B overcurrent is detected, stoppage of the vertical deflection is detected simultaneously. The symptom that is diagnosed first by the mircrocontroller is displayed on the screen.
Self-Diagnostic Screen Display
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.
To Bring Up Screen Test
In standby mode, press buttons on the Remote Commander sequentially, in rapid succession, as shown below:
Display > Channel 5 > Sound Volume - > Power ON
Handling of Self-Diagnostic Screen Display
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.
Clearing the Result Display
To clear the result display to “0”, press buttons on the Remote Commander sequentially when the diagnostic screen is displayed, as shown below:
Channel 8 > ENTER
Quitting the Self-Diagnostic Screen
To quit the entire self-diagnostic screen, turn off the power switch on the Remote Commander or the main unit.
+B overcurrent (OCP)
Occurs when an overcurrent on the +B (135V) line is detected by pin 72 of IC001 (A Board). If the voltage of pin 72 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.
I-Prot
Occurs when an absence of the vertical defl ection pulse is detected by pin 78 of IC001 (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 IC001 (A Board). TV will stay on, but there will be no picture.
METHOD OF SETTING THE SERVICE ADJUSTMENT MODE
Service Mode Procedure
1. Standby mode (power off).
2. Press Display > Channel 5 > Sound  Volume + > Power on the Remote Commander (press each button within a second).
Service Adjustment Mode On
1. The CRT displays the time being adjusted.
2. Press 1 or 4 on the Remote Commander to select the time.
3. Press 3 or 6 on the Remote Commander to change the data.
4. Press MUTING then ENTER to save into the memory.
WHITE BALANCE ADJUSTMENTS
1. Input an entire white signal with burst.
2. Set to Service Adjustment Mode.
3. Set the PICTURE and BRIGHTNESS to minimum.
4. Adjust with SBRT if necessary.
5. Select GCUT and BCUT with 1 and 4 .
6. Adjust with 3 and 6 for the best white balance.
7. Set the PICTURE and BRIGHTNESS to maximum.
8. Select GDRV and BDRV with 1 and 4 .
9. Adjust with 3 and 6 for the best white balance.
10. Press MUTING then ENTER to save into the memory.
MEMORY WRITE CONFIRMATION METHOD
1. After adjustment, pull out the plug from the AC outlet, then replace the plug in the AC outlet again.
2. Turn the power switch ON and set to Service Mode.
3. Call the adjusted items again to confi rm they were adjusted.
A BOARD ADJUSTMENTS H. Frequency (Free Run) Check
1. Input a TV mode (RF) with no signal.
2. Connect a frequency counter to base of Q502 (TP-25 H. DRIVE) on the A Board.
3. Check H. Frequency for 15735 ± 200 Hz.
V. Frequency (Free Run) Check
1. Select video 1 with no signal input.
2. Set the conditions for a standard setting.
3. Connect the frequency counter to TP-27 (V OUT) or CN515 pin 6 (V DY+) and ground on the A Board .
4. Check that V. Frequency shows 60 ± 4 Hz.
Drive (SCON)
1. Input a color-bar signal and set the level to 75%.
2. Set in Pro mode + PICTURE MAX.
3. Activate the Service Adjustment Mode.
4. Connect an oscilloscope probe to CV Board,
J1751Pin 12 (KR) (Red Out) .
5. Select SCON with 1 and 4 .
6. Adjust the value of SCON with 3 and 6 for 86 ± 3Vpp for 20/21 inch, and 96 ± 3Vpp for 24/25 inch.
Display Position Adjustment (DISP)
1. Input a color-bar signal.
2. Set to Service Adjustment Mode.
3. Select DISP with 1 and 4 .
4. Adjust values of DISP with 3 and 6 to adjust characters to the center.
5. Press MUTING then ENTER to save into the memory.
6. Check to see if the text is displayed on the screen.
Sub Bright Adjustment (SBRT)
1. Input a monoscope signal.
2. Activate the Service Adjustment Mode.
3. Set the PICTURE and BRIGHTNESS to minimum.
4. Select the SBRT item with 1 and 4 .
5. Adjust the values of SBRT with 3 and 6 to obtain a faintly visible crosshatch.
6. Press MUTING then ENTER to save into the memory.
Sub Hue, Sub Color Adjustment (SHUE, SCOL)
1. Input color-bar signal at 75%.
2. Activate the Service Adjustment Mode.
3. Set (PIC) to Max and (COL) to 50%.
4. Connect an oscilloscope probe to CV Board, CN301Pin 4 Blue Out.
5. Select the SHUE and SCOL item with 1 and 4 .
6. While showing the SHUE item, adjust the waveform with 3 and 6 until the second and third bars show the same level (V2 = V3 < 0.15Vp-p). Set Sub Hue -2 Step.
7. While showing the SCOL item, adjust the waveform with 3 and 6 until the fi rst and fourth bars show the same level (V1 = V4 < 0.15Vp-p). Set Sub Col +3 Step.
8. Press MUTING then ENTER to save into the memory.
V. Size Adjustment (VSIZ)
1. Input a crosshatch signal.
2. Activate the Service Adjustment Mode.
3. Select the VSIZ item with 1 and 4 .
4. Adjust value of VPOS with 1 and 4 for the best vertical center.
5. Press MUTING then ENTER to save into the memory.
V. Center Adjustment (VPOS)
Perform this adjustment after performing H. Frequency (Free Run) Check.
1. Input a crosshatch signal.
2. Activate the Service Adjustment Mode.
3. Select the VPOS item with 1 and 4 .
4. Adjust value of VPOS with 3 and 6 for the best vertical center.
5. Press MUTING then ENTER to save into the memory.
H. Center Adjustment (HPOS)
Perform this adjustment after performing H. Frequency (Free Run) Check.
1. Input a crosshatch signal.
2. Activate the Service Adjustment Mode.
3. Select the HPOS item with 1 and 4 .
4. Adjust the value of HPOS with 3 and 6 for the best horizontal center.
5. Press MUTING then ENTER to save into the memory.
H. Size Adjustment (HSIZ)
1. Input a monoscope signal.
2. Activate the Service Adjustment Mode.
3. Select HSIZ with 1 and 4 .
4. Adjust with 3 and 6 for the best horizontal size.
5. Press MUTING then ENTER to save into the memory.
V. Linearity (VLIN), V. Correction (SCOR), PIN Amp (PAMP), and Horizontal Trapezoid (HTRP) Adjustments
1. Input a crosshatch signal.
2. Activate the Service Adjustment Mode.
3. Select VLIN, SCOR, PAMP, and HTRP with with 1 and 4 .
4. Adjust with 3 and 6 for the best horizontal size.
5. Press MUTING then ENTER to save into the memory.
V. Angle (VANG), V. Bow (VBOW), Upper PIN (UPIN) and Low PIN (LPIN) Adjustments
1. Input a crosshatch signal.
2. Activate the Service Adjustment Mode.
3. Select VANG, VBOW, UPIN, and LPIN with 1 and 4 .
4. Adjust with 3 and 6 for the best picture.
5. Press MUTING then ENTER to save into the memory.
CIRCUIT DIAGRAM 
CLICK ON THE IMAGE TO ZOOM IN