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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It probable causes flashover and smoking inside the datwsheet. When Selected Video Out Mode, this signal which is selected by a video switch among 56pin or 54 pin input signal, is amplified 6dB and then output here.
If you get readings that do not make sense, you may be using your equipment in a way which is confusing it.
Before checking these circuits ,a kind of practical test method is introduced. Do not blindly trust your instruments. Color killer set too high internal control if it has one. The self-excitation oscillation circuit repeat again and datasheeg and produce la769311s signal about 40Khz.
Depending on the accurate level of horizontal free-run frequency we need, a low offset external resister is requested. This is hampered by the fact that there is much spread in HOT parameters.
Note that datasheeh the average person, the obvious question becomes: What happens to the HV? Nextcheck the setting of the color control – it may have accidentally been turned down.
The shut-up condition of V is still maintained. This means that the circuits of power supply, horizontal scanning, vertical scanning and video amplification are normal and they are not considered in the repairing.
In this case, the stability of the sync signal is depended on external signal. Do not expect to find the circuits shown above staring you in the face when you get your service manual. The phase of the signals, which are divided from chroma frequency and Snd-VCO frequency, will be compared together.
At the beginning of scanthe damper diode forward biased carries the bulk of the current from the yoke and flyback.
From tuner 64 SAW 3. The primary voltage that you see then is mostly a dqtasheet version of the secondary voltage, over the series base impedance. Using external vertical trigger to reset countdown circuit. The inductance of Damper Catasheet Yoke the flyback primary T and C,C forms a resonant circuit so that the Diode voltage climbs on C,C as the current goes down.
ELECTRONICS TRICKS AND TIPS: LA IC DATA SHEET
This is called anti-breathing. If brightness is a digital control, then you will need a schematic unless there is an pa76931s bad connection. When we add in the joke components only the horizontal deflection coil and S-correction capacitor or S-cap are actually shown above conditions are only slightly more complex: The output amplitude is 2Vp-p.
Also, in case of develop many chassis, this can contribute to speed up the development period. Then the discrepancy phase will transform to be current and output to pin 7. To prevent this ,some EHT information is fed to the contrast controller, to automatically reduce the picture brightness whenever the white content is too much.
The DC voltage is about 2. It also makes sense to identify exactly what is and is not working so that you will know whether some fault that just appeared was actually a preexisting problem or was caused by your poking. The scenario described below is only true in the steady state- the first few scans are different because the picture tube capacitance is still discharged.
A defective CRT can cause a lack of a primary color – R,G, or, B or a short between two colors which will mess up the color but is not likely to result in a black and white picture.
Above steps have accomplished the flyback function of quicky and cleanly reversing the current in T and ,as we will see,the deflection yoke as well. C If there were no damper diode D1this voltage would go negative and continue to oscillate as a damped sinusoid due to the resonant circuit formed by T and C,C and the other components However ,D1 turns on as the voltage negative and diverts the current through it clamping the voltage near0 -Vf for the diodes.
In this process, Ug does not put any current in the base of V, on the contrary, decreases the startup current of V rapidly.
There are a semi-infinite number of variations on this basic theme. It is virtually impossible for a defective CRT to cause a total loss of color.
A power supply going to one side of the control negative probably may be missing. An S-cap that changed value or selected to be the wrong value will result in distortion at the left and right sides of the screen: With modular systems like component stereos and computers, narrowing down a problem to a single unit should be the first priority.
In order to prevent the unsatisfied drive capacity of amplitude matching 1Vpp and load video circuit, chroma circuit, deflection circuitwe recommend application circuit below: It is not generated by special circuit.
(PDF) LA76931 Datasheet download
la76931 If you substitute a heavier la76913s more amps, more volts, more watts, faster switching, whatever for a lighter one, then there is a very big chance that it will fail earlier, not later. The wire may be soldered or just pressed in place in such a way that pulling it out is difficult or impossible without removing the cover.
With a basic understanding of how the equipment works, many problems can be dealt without a schematic.