Data IC LA Data Voltage PIN 1. SIF OUTPUT V PIN 2. IF AGC FILTER 0V PIN 3. SIF INPUT V PIN 4. FM FILTER V PIN 5. LA PIN 1= SIF OUTPUT [V DC] PIN 2= IF AGC FILTER PIN 3= SIF INPUT [V DC] PIN 4= FM FILTER PIN 5= FM OUTPUT [V~V] PIN 6= AUDIO. Part Number: LA Function: 64Pin LA for Color Television Receiver / SERVICE MANUAL. Maker: Unspecified Pinouts: LA
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Please add a 5. Scrape off all of the old glue and then clean thoroughly. This reduces the scanning speed near the edges.
Confirm the problem before diving into the repair. A standby power supply for the microcontroller and remote sensor. Do not start with the electronic test equipmentstart with some datawheet thinking. A failure in the video path, like a video output amplifier stuck at 0V, causes a high beam current that will not react to the contrast controller. The average value of the S-cap voltage will be positive.
A defective CRT can cause a lack of a primary color – R,G, or, B or a short dxtasheet two colors which will mess up the color but is not likely to result in a black and white picture. A The desired yoke current is not quite a sawtooth but includes two major corrections: The air gap stores energy, some of which may be tapped off during flyback by secondary rectifiers e.
After approximately 5 minutes or slightly longer, the screen voltage will wander anywhere from 75V up to maybe V, Adjustment of the screen control on the flyback has only a small effect and is not permanent. This means that also the switch -on moment of the HOT will vary with the load.
A power supply going dataaheet one side of the control negative probably may be missing. Regulator is based on the above datasgeet. Concerning to the phase and the width of blanking pulse, as before waveform is made up and datahseet suitably in FBP input circuit. Learn from your mistake. Defective chroma chip do not suspect this first just because it is probably very expensive.
The main filter capacitor C is very important. In the power design of LA seriesthere is a separate switch mode power supply that provides all of the DC voltage. It has the effect of modifying the sawtooth current into a sine-wave shape.
Excess beam current is a common cause la766931s this and should be avoided by the beam current limiter. The reason is that the drive conditions will now be wrong most likely underdrive and the transistor will overheat from too high conduction losses. Also, in case of develop many chassis, this can contribute to speed up the development period.
Ultimately this will cause saturation of the ferrite core. The detail checking and repairing steps are as follow. The current in the base of V Ib also decreases al76931s.
LA Datasheet –
But they make no use of the stored magnetic energy, they load the primary directly during the scan part. One large filter capacitor to smooth the unregulated DC. Do not datashert when you are really tired – it is both dangerous and mostly non-productive or possibly destructive. Enable Killer circuit Ever when the color control is minimized, but maybe there is still has little color left in the picture.
(PDF) LA76931 Datasheet download
Chapter Five Typical Failure Analyse. The blanking output level of RGB is about 1. This makes it extra difficult to optimize the base-drive because there is only a limited time interval where the HOT may be switch on and that interval is shorter with high beam current load.
Select vertical sync system. It is virtually impossible for a defective CRT to cause a total loss of color.