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Loss of proper vertical deflection

Vertical is spread waaay too far. Vertical size and height pots have little or no effect. Noticed some discoloration (traces seem okay) of pc board in area of R505 and near some other 500 series components; resoldered, no help. Suspect an open R or a lytic or maybe the IC? Don't have a schematic or manual so unable to check pin volts or R values.

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Re: Loss of proper vertical deflection

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Posted on Jan 22, 2008

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21" sony tv horizontal amp short what is the

The most common cause of this symptom, by far, is the loss of vertical deflection amplifier. It usually requires the replacement of the vertical output transistor or some component associated with it. The cost of repair would run around $150 to $200 depending on the exact parts replacement and the shop that does the work.

i hope this will be help full to you .

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Error code 2-3 it turns on and inmediately goes down

As far as I can recall, this set uses a standard vertical IC. Check that first. It should be an LA7837 or somethint similar. Also, check the capacitors in the same circuit as well as the supply voltages to the chip. If that fails to resolve the problem, please update this and we'll move on to other areas.

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this is a indiciation of loss of vertical deflection. is the a thin horizontal line? I have found feferences that capacitor c517 in the horizontal cuircit was shorted cause this .. cant be sure... also other components that might be at fault is the vertical ic 1509 transitor q1505 vertical buffer.

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I have a 55 in Sony Grand Wega LCD TV that has some strange lines that look like cobwebs. They seem to be floating behind screen. What could it be? The TV is 6 years old

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A single horizontal line means that you have lost vertical deflection. High voltage is most likely fine since there is something on the screen.

This could be due to:

Dirty service switch contacts. There is often a small switch located inside on the main board or perhaps accessible from the back. This is used during setup to set the color background levels.
may be a jumper plug or other means of selecting service mode - not an actual switch.

When moved to the 'service' position, it kills vertical deflection and video to the Tube. If the switch somehow changed position or got dirty or corroded contacts, you will have this symptom. Flip the switch back and forth a couple of times. If there is some change, then replace, clean, resolder, or even bypass it as appropriate.

Bad connection to deflection ports or other parts in vertical output circuit. Bad connections are common in TVs and monitors. Check around the pins of large components like transformers, power transistors and resistors, or connectors for hairline cracks in the solder. Reseat internal connectors. Check particularly around the connector to the deflection ports on the Tubes.

Bad vertical deflection IC or transistor. You will probably need the service manual for this and the following. However, if the vertical deflection is done with an IC, the ECG Semiconductor Master Substitution guide may have its pinout which may be enough to test it with a scope.

Other bad parts in vertical deflection circuit though there are not that many parts that would kill the deflection entirely.

Loss of power to vertical deflection circuits. Check for blown fusable resistors/fuses and bad connections.

Loss of vertical oscillator or vertical drive signals.

The most likely possibilities are in the deflection output stage or bad connections to the yoke.

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