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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Thursday, 7 February 2019

SHARP 28JS-74S – HOW TO ENTER SERVICE MODE – LED FLASHING CODES – SMPS CIRCUIT DIAGRAM - NVM RE-WRITE

Sharp 28JS-74S – How to enter service mode – LED flashing codes – SMPS circuit diagram - NVM re-write


PAL/SECAM BG SYSTEM COLOUR TELEVISION - Sharp 28JS-74S – LED blinking codes – Service mode -  How to rewrite data in NVM – SMPS Schematic
SERVICE MODE
The Service Mode is provided to enable the engineer to correctly set up the receiver to the CRT fitted in the set.
Note that these adjustments may vary from one receiver to another.
To enter the Service Mode, carry out the following procedure.
1. Connect a test pattern to the antenna terminal.
2. Tune the receiver to this signal.
3. Turn the receiver off using the mains switch.
4. Press volume down and channel up buttons on the front of the receiver at the same time.
5. Keeping these buttons pressed, turn the mains on.
6. When the set starts up it will be in Service Mode.
7. Release the two buttons.
Use the channel up and down buttons to move between the options.
Use the volume control buttons to change the data.
To store the data, use the stand-by button on the remote control.
To exit the Service Mode, turn the receiver off using the mains switch.

When the Service Mode is entered the following On Screen Display appears
SERVICE SOFTWARE version ∗∗.∗∗
SW on: XXXX SW off: XXXX Hours ON: XXXX
The figures displayed in the “XXXX” locations are hexadecimal representations of the number of times that particular function has been executed. For example if the hexadecimal number displayed after “SW ON” was “0E4A”, this would correspond to the receiver being turned on 3658 times.
The following adjustments can be carried out in the Service Mode.
Horizontal Shift
East West Width
Pin Phase
Pin Amp
Upper corner correction
Lower corner correction
Extreme Corner Correction
Vertical Linearity
Vertical angle
Vertical bow
Vertical Amplitude
S Correction
Vertical Shift
Red Cut Off
Green Cut Off
Blue Cut Off
Alter NVM Pag (Page)
Alter NVM Pos (Position)
Alter NVM Val (Value)
Teletext Mix Mode Contrast
Teletext Contrast
OSD Contrast
DVCO Adjustment (Only PAL)
DVCO Adjustment (Only NTSC)
AGC Adjustment
Auto Installation On/Off

The following geometry adjustments can be carried out.
Horizontal Shift
East West Width
Pin Phase
Pin Amp
Vertical angle
Vertical bow
Upper Corner Amplitude
Lower Corner Symmetry
Extreme Corner Symmetry
Vertical Amplitude
S Correction
Vertical Shift
Vertical Linearity
Just in case the TV set requires a full geometry adjustment, please proceed first with Vertical according to the above order, and after that, adjust Horizontal according to the above order.
LED FLASHING CODES
If the TV set does not work and the power indicator is flashing, follow the sequence according to the information to fault finding.
> Unable to read or write into NVM: 66% ON, 33% OFF twice and OFF for a second.
> MSP failure: 66% ON, 33% OFF for three times and OFF for a second.
> SDA 9380 failure: 66% ON, 33% OFF for four times and OFF for a second.
> SDA 9402 failure: 66% ON, 33% OFF for five times and OFF for a second.
SMPS SCHEMATIC (Split and Full)
How to retrieve the IC6002 (Flash Memory).
Desoldering the Shield Case Cover.
Introduce the screwdriver through the hole.
Insert the screwdriver between the IC6002 and its socket. Push up the IC6002 with the screwdriver as in Figure 16.
Retrieve the IC6002.
How to retrieve the IC6002 with pincers (Flash Memory).
Desoldering the Shield Case Cover.
Introduce the pincers into the hole.
Insert the pincers and take hold the IC6002. Pick up the IC6002 with the pincers as in Figure 18.
Retrieve the IC6002
How to rewrite data in NVM.
The NVM (Non Volatile Memory) is a read/write device which function is to keep data even in the case of TV set is switched off.
Part of these data is recovered every time the TV is switched on, and, of course, if user makes any change in the user settings (i.e brightness, contrast, etc..).
The NVM data could be corrupted if any external destructive action is carried out (Sparks of high voltage) or if a problem happens to the IC itself (defective IC or damaged IC). In order to keep the data un-corrupted, several protection countermeasures are implemented; one of them is to have a copy of all the NVM relevant parameters in the FLASH (which keeps the software for the microcontroller). So, the procedure to follow if the NVM IC is damaged or the data is lost is the following:
a) If the NVM IC is substituted for a new (BLANK) one, it is possible to write the NVM asking for the file which corresponds to the model or let the microcontroller write the default data which is written inside. This process is automatically carried out when the blank device (NVM) is soldered and TV is switched on for first time after the modification. The TV starting time is longer than normally due to the rewriting procedure.  In both cases a new geometry adjustment should be done because of CRT and chassis tolerances.  
b) If the NVM is corrupted and some data is lost, there are internal software protection to recover the data related with configuration of ICs but user data can be lost (some channel data or user settings for video, audio etc..). It is possible to recover this data forcing an auto installation and setting the user settings again.
Posted By: FRANK at 02:33
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