REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

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Thursday, 14 March 2019

RCA L15D20, AOC 1255A LD7552BICOMS SMPS CIRCUIT DIAGRAM - 15 INCH LCD TV – HOW TO ENTER THE SERVICE MODE,SERVICE MODE, WHITE BALANCE ADJUSTMENTS AND MORE... #REMOTE CONTROL PART NUMBER: R130D1

RCA L15D20, AOC 1255A LD7552BiCOMS SMPS CIRCUIT DIAGRAM - 15 inch LCD TV – How to enter the service mode,Service mode, white balance adjustments and more... #Remote control part number: R130D1

How to enter service mode, white balance adjustment, LVDS, SMPS and back-light inverter board schematic - RCA L15D20 - 15 inch LCD TV [Universal remote control set-up codes for RCA TVs]
Remote control part number: R130D1
White Balance, Luminance Adjustment 
Approximately 30 minutes should be allowed for warm up before proceeding white balance adjustment.
First adjust PC mode and then adjust AV mode, HDMI mode, component 480i mode, component 480p mode. Before started adjust white balance, please set the Chroma-7120 MEM. Channel 01 to Cold color MEM. and channel 03 to Normal color, MEM. and channel 04 to warm color, MEM.(cold parameter is x = 289, y =304; normal parameter is x =299, y =315; warm parameter is x =313, y =329 )
Note: The tolerance of the color coordinates should be less than ± 20.
How to setting MEM. channel you can reference to Chroma-7120 user guide or simple use “ SC” key and “ NEXT” key to modify x, y , Y value and use “ID” key to modify the TEXT description
Following is the procedure to do white-balance adjust.
Note: Step of AV, HDMI, COMPONENT480i, COMPONENT480p mode adjustment is the same as PC mode,
PC mode:
Ⅰ. In the TV mode adjust volume to zero and press number key 9 > 8 > 7 > 6.
It will achieve the factory mode [Service Mode].
Select the item of White Balance and press right key to enter it.
In the White Balance you can adjust 8 items.
1-3 items is RO, GO, BO -- R, G, B Bias adjust.
4-6 items is RG, GG, BG -- R, G, B Gain adjust.
7 item needn’t adjust
8 items is color temperature select: Cool, Normal, and Warm.
Bias (Low luminance) adjustment
1. Set the raster pattern (Black pattern with 1024×768) Input.
2. Adjust the brightness on OSD until chroma 7120 measurement reach the lowest value.
Gain adjustment
A. Adjust Cold color-temperature:
1. Set the Contrast of OSD function to 80 and Adjust Brightness to chroma-7120 Y>180 cd/m2
2. Switch the chroma-7120 to RGB-mode (with press “MODE” button)
3. Switch the MEM. channel to Channel 01 (with up or down arrow on chroma-7120)
4. The LCD-indicator on chroma-7120 will show x =289, y =304, Y>180cd/m2
5. Adjust the 4 item: RG, until chroma 7120 indicator reached the value R=100
6. Adjust the 5 item: GG, until chroma-7120 indicator reached the value G=100
7. Adjust the 6 item: BG, until chroma-7120 indicator reached the value B=100
8. Repeat above procedure until chroma-7120 RGB value meet the tolerance =100±2
9. Switch the chroma-7120 to x, y, Y mode with press “MODE” button to check the color temp is in SPEC. or not.
10. Enter the 8 item to select another color temperature to adjust.
LVDS  schematic
Adjust Normal color-temperature
1. Set the Contrast of OSD function to 80 and Adjust Brightness to chroma-7120 Y>180cd/m2
2. Switch the chroma-7120 to RGB-mode (with press “MODE” button)
3. Switch the MEM. channel to Channel 03 (with up or down arrow on chroma-7120)
4. The LCD-indicator on chroma-7120 will show x =299, y =315, Y>180cd/m2
5. Adjust the 4 item: RG, until chroma 7120 indicator reached the value R=100
6. Adjust the 5 item: GG, until chroma-7120 indicator reached the value G=100
7. Adjust the 6 item: BG, until chroma-7120 indicator reached the value B=100
8. Repeat above procedure until chroma-7120 RGB value meet the tolerance =100±2
9. Switch the chroma-7120 to x, y, Y mode with press “MODE” button to check the color temp is in SPEC. or not.
10. Enter the 8 item to select another color temperature to adjust.
Adjust Warm color-temperature
1. Set the Contrast of OSD function to 80 and Adjust Brightness to chroma-7120 Y>180cd/m2
2. Switch the chroma-7120 to RGB-mode (with press “MODE” button)
3. Switch the MEM. channel to Channel 04 (with up or down arrow on chroma-7120)
4. The LCD-indicator on chroma-7120 will show x =313, y =324, Y>180cd/m2
5. Adjust the 4 item: RG, until chroma 7120 indicator reached the value R=100
6. Adjust the 5 item: GG, until chroma-7120 indicator reached the value G=100
7. Adjust the 6 item: BG, until chroma-7120 indicator reached the value B=100
8. Repeat above procedure until chroma-7120 RGB value meet the tolerance =100±2
9. Switch the chroma-7120 to x, y, Y mode With press “MODE” button to check the color temp is in SPEC. or not.
10. Enter the 8 item to select another color temperature to adjust.

Switch different source
Press the source key on the remote control to switch different source to adjust the AV, HDMI, CONPONENT 480i
and COMPONENT 480p mode.
Press “Exit” button on remote control to quit from factory mode
SMPS and back-light inverter schematic
Click on the pictures to magnify