REPAIRING AND NOT THROWING AWAY

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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Monday 11 March 2019

XOCECO LC-27FB18 / 32FB18 SERVICE MODE

XOCECO LC-27FB18 / 32FB18 SERVICE MODE


XOCECO LC-27FB18 /32FB18 

SERVICE MODE 

SERVICE MODE
Method for using factory menu:
 Press ”VOL” button to decrease the volume to 0, then press”9876” to enter level one factory menu. Press ”CH+” and “CH-“ to select adjustment page, then press “OK” to access. Press “CH+” and “CH-“ to move cursor up and down, when the cursor stays on a certain adjustment item, press “VOL-“ and “VOL+” to adjust. 
Press “MENU” exit to the level one factory menu; press “EXIT” to exit from the factory menu at any situation.
Note: channel switch isn’t available at adjustment menu, only after return to level one factory menu, you can switch channel.
Adjustment of white balance
1. input 16 level gray-scale signal from VG849 to HDMI channel (TMIING: select a support format of HDMI), enter white balance adjustment page of factory menu, select cool color temperature of item, fixed WBGG_HDMI to 50H, adjust WBRG_HDMI, WBBG_HDMI, let the color coordinate of third level on the right be (270,283) at 400nits; fixed WBBO_HDMI to 50H, adjust WBRO_HDMI, WBGO_HDMI, let the color coordinate of third level on the left be (270,283) at 5nits. The brightness of 400nits and 5nits may obtain by adjusting the contrast and brightness of menu.
2. input 16 level gray-scale signal from VG849 to AV channel (TMIING:968), enter white balance adjustment page of factory menu, select cool color temperature of item, fixed WBGG_NTSC to 50H, adjust WBRG_NTSC, WBBG_ NTSC, let the color coordinate of third level on the right be (270,283) at 400nits; fixed WBBO_ NTSC to 50H, adjust WBRO_ NTSC, WBGO_ NTSC, let the color coordinate of third level on the left be (270,283) at 5nits. The brightness of 400nits and 5nits may obtain by adjusting the contrast and brightness of menu.
3. input 16 level gray-scale signal from VG849 to VGA channel (TMIING: select a support format of VGA), enter white balance adjustment page of factory menu, select cool color temperature of item, fixed WBGG_VGA to 128, adjust WBRG_ VGA, WBBG_VGA, let the color coordinate of third level on the right be (270,283) at 400nits; fixed WBGO_VGA to 128, adjust WBRO_VGA, WBBO_VGA, let the color coordinate of third level on the left be (270,283) at 5nits. The brightness of 400nits and 5nits may obtain by adjusting the contrast and brightness of menu.
4. input 16 level gray-scale signal of 480I from VG849 to YPbPr channel, enter white balance adjustment page of factory menu, select cool color temperature of item, fixed WBRG_YPbPr480I, WBGG_YPbPr480I, WBBG_YPbPr480I to 128, and WBRO_YPbPr480I to 128, adjust WBRO_YPbPr480I, WBBO_YPbPr480I, let the color coordinate of third level on the left be (270,283) at 5nits. The brightness of 5nits may obtain by adjusting the contrast and brightness of menu. Input format signals separately list on table 1, repeat the operation above until the white balance pass muster.
Note: the white balance adjustment of VGA and YPBPR must be done at the situation that the white balance adjustment of HDMI is accurate.
Performance check
1 TV function
Connect RF-TV terminal to the central signal source, enter the setup menu→ auto search, check if there is station skipping, the output of earphone and speaker, the picture are normal.
2 AV/S-VIDEO terminal
Input AV/S signal, check if the picture and sound are normal.
3 YPbPr/YCbCr terminal
nput YUV signal (VG-849 signal generator), separate input YUV format signal
Method of software upgrading
1. Connect RS-232 cable to computer and TV set. The cable must be a female to female RS-232 cable, and the line is TXD to RXD and RXD to TXD cross-link. It’s popular for PC to PC connection.
2. If the computer has no RS-232 serial port(e.g. Notebook PC),you needs a additional USB to serial port cable.
3. Copy the update tools (iDev.exe) to the path you want to do it, and double click it.
4. Select “setup” menu.
5. Confirm the Serial port is right. Base on the port which using for update. And set the band rate to 115200 (default).
6. Select the “Image path” menu.
7. Confirm it’s the right file.
8. If it’s not right(Maybe you didn’t select it before),click the “…”button to select “*.ecc” file. Sometimes the image file you got it will be “*.rar ”or “*.zip” zip file, needs unzip it first.
9. You also can click the setup button to select and config, but please don’t select the red one(update boot sector)
10. Then click the “down” button.
11. You can see the “waiting” window.
12. Then power (off then) on the TV set.
13. After download, it will be burning.
14. Last it will be finished
15. Press the (IR/ locate keypad) power key and holding for several second to force power off TV set, then power on again. It would be ok now. If it’s failure you can try once again.
Working principle analysis of the unit
1. NTSC signal flow:
Antenna reception NTSC signal send to the integrative tuner FQD1236, which contains HF and IF amplifier circuit and video decoding circuit. It is controlled by main IC ZR39660 (inside CPU) through I2C bus. The NTSC signal via frequency tuning, HF amplification, IF amplification, system switching and decoding, output video signal TV-CVBS of 1Vpp and sound IF signal (SIF). TV-CVBS and AV1-CVBS, AV2-CVBS input from AV terminal, via switch IC HEF4052 to output signal, one way send to ZR39660 for VEDIO DECODER, DEINTERLACE and SCALER, then send to LVDS level drive for LCD screen, another way is output through AV output socket as AV OUT. The sound IF (SIF) is fed into demodulation IC CAS220, via decoding and A/D conversion, it is fed into ZR39660 for analog control in the format of I2S. ZR39660 outputs audio data of I2S format, it is fed into audio D/A converter IC CS4344, output analog L/R signal. The L/R signal and sound signal of PC/YPRPB via diverter switch HEF4052BT, send to R2S15900SP (sound processing and volume control). Select right/left sound channel, their send to digital sound amplifier TPA3001 amplify, then send to speaker.
2. ATSC signal flow:
Antenna reception ATSC signal send to tuner FQD1236, after frequency tuning, HF amplification, IF amplification and SAW FILTER, output IF signal to demodulation chip CAS220, via VSB or QAM demodulation, Sound stereo decoder, fed to ZR39660 for information source decoding in the format of standard serial TS stream. HD video signal via decoding to A/D conversion and OSD superposition, at last send to LVDS drive level for PDP panel. HD audio signal, via decoder built-in ZR39660, resumed to multi- channel sound of Dolby AC-3, at the same time output data stream of I2S format and S/PDIF data stream. Audio data of I2S format is fed to audio D/A conversion chip CS4344 to output analog L/R signal. S/PDIF data stream directly output from optical fiber interface.
3. PC/YPrPb signal flow
PC and two YPBPR signal via matched resistance, it a-c couple to video switch SN74CBT3257CDR, via switching to selected signal to Triple Video A/D Converter MST9883 A/D conversion. Send B/G/B of 24 bit to main IC ZR39660 digital decode, image scale and OSD superposition, then send
to LVDS level drive for LCD screen. Sound signal (PC, YPrPb) via switch diverter HEF4052BT to output signal, it send to R2S15900SP (sound processing and volume control) switch of audio. Select right/left sound channel, their send to digital sound amplifier TPA3001 amplify, then send to speaker.
4. HDMI signal flow
HDMI video signal is directly fed to main IC ZR39660 (with HDCP function of HDMI) digital decode, image scale and OSD superposition, then output LVDS drive level for screen. HDMI audio signal, via decoder built-in ZR39660,output data stream of I2S format and S/PDIF data stream at the same time. Audio data of I2S format is fed to audio D/A conversion chip CS4344 to output analog L/R signal. S/PDIF data stream directly output from optical fiber interface.
Posted By: FRANK at 03:32
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