Re: Does the TOSHIBA TA8445K Vertical Deflection IC fails...
Hola tengo un tv onwua que no me habre el verticar ya revise los voltajes y estan bien pero en la pata 11 tengo solo 7 voltios en ves de 12 voltios cual puede ser el problema de mi parte muchas gracias.mi email es [email protected].
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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. (On some sets, this is located on the CRT neck board and 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 CRT. 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 yoke 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 yoke on the CRT.
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
Check the deflection yoke connection cable for any loose contact at its connection socket at main board side. Unplug the connector out from the socket, and re-plug it back for at least tow times. Check the solder terminals of all connections to horizontal output. It will be best to re-solder all suspected solder terminals there. [horizontal sweep signals to the deflection yoke is absent now. Only vertical sweep is present now]
Hi Florendo,
Check the supply voltage at pin# 2 of TDA7056 IC, if you havn't voltage, trace it, the fusible resistor might be open. Replaced if open then power on the unit. If the fusible resistor burned again, this is an indication that youre IC is shorted(need replacement). If nothing happens to the resistor and the supply voltage is present now in pin#2 your IC need to be replace also because this is already open. For more info click this http://pdf1.alldatasheet.com/datasheet-pdf/view/19422/PHILIPS/TDA7056.html.
Hope I helped you.
Have a nice day!
Thanks for using Fixya.
You haven't vertical deflection.
The ff caused the problem.
1. Dry joints on the vetical section.
2. Blew Vertical ouput IC
3. Open yoke vetical winding.
4. No vertical output from jungle IC.
5. Open supply for vetical ic due to open fusible resistor.
I've suspect that you have #1 and #2 fault. This is not Diy so I've advice you to send to repair shop or look for a qualified tech to isolate the problem.
Hello, you can do this yourself by opening the back cover of the television CAUTION: To prevent damage to the CRT phosphors, immediately turn down the brightness so the line is just barely visible. If the user controls do not have enough range, you will have to locate and adjust the master brightness or screen/G2 pots.
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. (On some sets, this is located on the CRT neck board and 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 CRT. 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 yoke 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 yoke on the CRT.
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.
CAUTION: To prevent damage to the CRT phosphors, immediately turn down the brightness so the line is just barely visible. If the user controls do not have enough range, you will have to locate and adjust the master brightness or screen/G2 pots.
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. (On some sets, this is located on the CRT neck board and 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 CRT. 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 yoke 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 yoke on the CRT.
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. Good luck..
It could be the vertical output IC, but there may be other possible causes which include:
- bad solder contacts on deflection yoke connectors or dirty connector contacts (on the circuit board and / or on the picture tube neck)
- bad solder contacts on the vertical output IC or associated components (check for little cracks in the solder around the pins, these are so called "cold" or bad / broken contacts)
- power loss to the vertical output IC - check for any burned resistors or other components around that IC, assuming you know which one it is - see which ICs are connected to the wires going to the deflection yokes (coils) on the picture tube neck and check them well.
You need to resolder any bad contacts, clean any dirty pins on the connectors and replace any burnt out components (assuming you can still determine the type or value of the component).
Since you mentioned the problem occurs once in a while, this means that the IC probably fails when it warms up, which can often happen if there are loose connections or bad solder contacts.
Anyway, it could turn out to be a faulty IC, i just suggested a few other things that can be fixed quite easily, and possibly without the need to replace any of the components.
I see with my oscilloscope, that vertical amplifier( I.C. AN5534 ) oscillate and output signal is not normal.When i measure vertical deflection yoke see about 33 ohms . normal value is about12 to16 ohms.So i disconnect the two parts , measure one by one and i see that one off the parts is not good. So i change the deflection yoke and solve the problem. Best wishes ! Nick
Defective components in vertical deflection and output circuit inclusive of vertical output device, coupling capacitors, and yoke connectors. Passive devices such as electrolytic capacitors, coils, and resistors to/from power supply circuits. If your tele is more than 10 years old dump it and get a newer product. $100 USD is a fair price to diagnose and attempt service, depending on age and configuration. Older products may not have replacment
parts available at any repair cost.
There may be a pot for adjusting the vertical size. If so, it may be dirty. If you can find it, try adjusting it which could clean it. BE CAREFUL -voltages are very high.
Vertical deflection circuit in Sharp television model no. 21V-W99
Please speak in English, ruben. Thank You.
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