No schematic and cannot determine why there is no horizontal drive signal.
This set has failed and the Horizontal output was bad. I have determined that there is no horizontal drive signal and have no way to find where it has failed. There is a high positive voltage on the base of the Hor. output transistor which is certain to destroy another transistor. I need a schematic and advice will be appreciated! J.
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If you wish to know more, check this site. It has schematic digrams of some popular brand TVs' horizontal output section published. http://electronicshelponline.blogspot.com/
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6 blink's means H stop or Horizontal Drive failure. Check the Jungle and its soldering connection terminals for possible bad soldering or loose connection. In some cases jungle ic found defective.also check your horizontal drive transformer windings and connection that is connected at the base of horizontal output transistor. Open winding or loose connection would result to absence of horizontal drive at the base of horizontal output transistor..
Six blinks of standby light in Sony TVs denotes the absence of horizontal oscillation.
No Horizontal (H STOP), no raster, goes to the blinking self-diagnosis function immediately. Check C515 & 516 and the jungle IC, IC206. In most cases the Ic is foud defective. anyway check its soldering points for any loose contact, or bad solerings. Check the line drive transformer, a very little transformer soldered directly to the main printed circuit board, very close to the horizontal output transistor. Check its primary winidngs for open. If it gets open no horizontal drive signal will be present at the base of the horizontal output transitor, that also may the cause of horizontal stop.
I assume this is the exact replacement transistor? If it is not then use the original part with no substitutes. Next be sure the transistor has heatsink compound applied and is securely tightened to the heatsink. You say the B+ is normal, but does it remain "normal"? I would monitor the B+ also at power up to be sure it is being regulated. Another critical issue is the drive signal at the base of the HOT. If you have a o-scope & schematic check this carefully not only for amplitude, but wave shape & timing. This determines the on/off time of the HOT. Check components in the base circuit (there are only a few) as perhaps they were damaged when the HOT originally failed. If you have a high voltage meter make sure the voltage is within spec. the retrace tuning cap. in the collector may have changed value allowing excessive amplitude of the pulse. One final thought, after running the set for a time is the HOT excessively warm. It should be slightly hot, but not to the point of burning your finger. If it is too hot I would be suspicious of the drive signal, and or heatsinking.
The most common fault with this model is the flyback transformer assembly is defective. Along with this, the horizontal output transistor may have also failed. In some cases this failure occurs because there is a drive problem coming from the horizontal scan driver circuit that is ahead of the horizontal output circuits. There may also be some support components that triggered the fault in the first place and would also be required to be replaced. When there is this type of failure, it is possible that the power supply may also need some service.
On more rare occasions, there may be a simple failure from the main power supply buss, or a failure in some other circuit that is putting the power supply in to protect mode.
An experienced TV tech who knows your model of Sony set can troubleshoot it and determine the exact failures. He can then give you an estimate.
This model of CRT set was considered to be an excellent TV set. Unfortunately when the full digital service is established as the standard, and the analog service is discontinued, you will require a digital to analog conversion box for this set to work with TV stations. Some cable TV and satellite TV companies will be supplying the analog signal in their standard package.
This might be a problem with the High Voltage, CRT, or the video circuitry. I would first suggest that you have a qualified TV repair technician troubleshoot and repair your televisions. Because these section contain dangerous voltages and can kill you if you make a mistake. So that being said here are some suggestions that you can pass on to the technician:
Check the voltage and signal level from the Video processor to the CRT socket board (this should determine if the video signal is good and that the biasing voltages on the video section components is good)
Check the voltage and signal levels of the Horizontal and High Voltage power supply section (This should determine if the High Voltage supply to the CRT is good and that the circuits of the horizontal section are functioning as specifications mandate)
Check the anode voltage on the CRT with a HV probe and do a diagnostic of the CRT with a CRT Test set (Something like the B&K 490B CRT Analyzer). (The test with the probe will determine if there is sufficient voltage at the anode of the CRT, and the CRT analyzer test will determine if the CRT is defective).
While the horizontal output is often the culprit you need to check some other things out first before jumping in and changing parts. Many sets, due to the high voltages and high amounts of heat they produce are prone to having bad solder connections. Look around the horizontal transformer for one leg than may be loose/desoldered. Also check the connections on the relay, they can come loose (you may even see some black charred discoloration) from repeated on/off cycles and the heat/cool that happens in the sets normal life. Also look at the connections at the flyback transformer. Re-solder all that are not nice and shiny. If you have a DC voltmeter, verify that you are getting your B+ voltage (approx 160V )up to the horizontal output. If not, look to the low voltage power supply. If it's there and still nothing and all the connections look to be good, check the horizontal drive transistor (smaller transistor that feeds the signal to the base of the horiz. output).
Probably 80%of the time you'll find a bad connection and be off and running again. While you're in there, re-solder the vertical output ic as a precaution. Panasonics (and other brands) are known for the legs of those ics getting loose.
The answer is yes, if all you have to do is to adjust the horizontal hold control (usually located on the back of the TV)
The answer is no (with caveat) if you have to open up the set. This problem occurs when the horizontal oscillator is drifting off its set frequency of 15,750 Hz This can be caused by a component or components changing in value, or the problem could be caused by the loss of or decrease in the amplitude of the horizontal sync pluses within the video signal. Such a loss of amplitude can take place from the output of the Video detector to the Horizontal mixer stage (uses the Video pluses and the Horizontal oscillator to sync the picture). This means that you will be working around a hazardous section of your TV.
The caveat is if you have a background in electronics and you have the proper equipment.
1) schematic diagram of the TV to see where TV test-points are
2) multimeter to measure DC voltages at test points
3) oscilloscope to view waveform patterns in the horzontal section of the TV
4) Signal generator to produce a know good signal into the TV set.
5) Isolation Transformer to connect the TV power plug to to isolate the Tv ground from earth ground and allow proper connectivity for test equipment (plug the unit under test into the isolation transformer and the test equipment into the wall outlet.)
I hope this answers your question,
Your main power supply may have failed or you've lost the horizontal drive pulse to the the horizontal output transistor. Also the flyback may be bad and the horizontal output transistor may be shorted. If this is the case the main power supply will not start up.
These are a few things that may have happened.