No chassis type nr? Its a familiar pcb I have worked on that type before ill have a look what ive got....in the meantime check for poor soldered joints....around the primary side and the line output stage , and maybe a replacement filter capacitor may be needed...

i have checked for the joints all are good. if snubber capacitor goes bad what happens. i have doubt only on big filter capacitor and snubber capacitor.

 

No chassis type nr? Its a familiar pcb I have worked on that type before ill have a look what ive got....in the meantime check for poor soldered joints....around the primary side and the line output stage , and maybe a replacement filter capacitor may be needed...

In the back of the TV it have only model number. where can i find the chasis number?
i have doubt on big filter capacitor and snubber capacitor. i cannot tell that as clear becoz i am a beginner. my knowledge is very little as yet. but i am reading everything what ever i can find on net.
if i can manage to repair this TV it will be a good start for me.

 

Take a look at the pdf.
I appreciate a better picture of the track side.

I have marked some point on the board. 1-7 are test points. I need you to measure the DC voltage at these respective points.
The GND shown is your DMM GND reference point.
Just tie the meter negative to the GND point, and leave the black probe connected securely. Put the DMM in VDC range ( 0-50V range is needed here).
Apply power to the TV. And measure the ( connect the RED probe) to each point and note down the voltage.
I need the voltage level at points 1~7 to figure out the next step.

 

Take a look at the pdf.
I appreciate a better picture of the track side.

I have marked some point on the board. 1-7 are test points. I need you to measure the DC voltage at these respective points.
The GND shown is your DMM GND reference point.
Just tie the meter negative to the GND point, and leave the black probe connected securely. Put the DMM in VDC range ( 0-50V range is needed here).
Apply power to the TV. And measure the ( connect the RED probe) to each point and note down the voltage.
I need the voltage level at points 1~7 to figure out the next step.

1=12.9V
2=11.5V
3=13V
4=11V
5=10.3V
6=10.1V
7=11V
i used 200 DC on DMM. it dont have 50 on it. but it have 20 instead.

 

OK from the readings, I am sure the relay is not being switched on.
Thus the filter cap won't have any voltage.
We need to see how the relay is switched.

 

Look at the pdf.
Post a good quality PNG file that I can zoom in.
Remember the area of the square is important.
Need to see the board from both sides of the PCB

 

Look at the pdf.
Post a good quality PNG file that I can zoom in.
Remember the area of the square is important.
Need to see the board from both sides of the PCB

Thank you so much Sir as I reach home I will take a pic and post you. But good quality png is big in size and site not allowing me to post big files. What to do.

 

Make it less than 1mb. it will be fine

 

Make it less than 1mb. it will be fine

if i make it 1mb it is not showing as clear as pdf. so i am uploading pdf for your kind review.

 

Cut off power from TV, wait for a few minutes for the caps to discharge.
Put the DMM in resistance range.
Measure the Resistance in all three switches shown in pdf.
Measure the resistance while switch is not pressed and then press it, note down the six readings and post them

 

Now look at this pdf.
See 2 zener diodes. Check them in circuit for dead shorts. Put the DMM is diode check mode and them check the two zeners in forward and reverse. Post the readings (4 readings).
Next I need to know the number written on IC2702.

PS. I might not reply soon. But tomorrow this time I will be back.

 

No chassis type nr? Its a familiar pcb I have worked on that type before ill have a look what ive got....in the meantime check for poor soldered joints....around the primary side and the line output stage , and maybe a replacement filter capacitor may be needed...

A fault I've sometimes seen on rectifier-reservoir electrolytics, is when the solder lugs are riveted on - the switch on surge sometimes spark-erodes the point of contact between the lug & rivet. Eventually, its not even intermittent - just open circuit.

 

Cut off power from TV, wait for a few minutes for the caps to discharge.
Put the DMM in resistance range.
Measure the Resistance in all three switches shown in pdf.
Measure the resistance while switch is not pressed and then press it, note down the six readings and post them

i took the power cable out. and let the capacitors discharge full. capacitors charges only when i on the power button. if i just plug in the power cord the capacitors wont charge. this is for your information.

then i put the DMM in 200k setting and took the readings. the readings are as follows.

power button = 35.5k
Volume Down = 34.5K
Volume Up = 29.3k

when i press the button it is same values. when i hold the buttons pressing, all the readings of all the buttons are 0.

 

Now look at this pdf.
See 2 zener diodes. Check them in circuit for dead shorts. Put the DMM is diode check mode and them check the two zeners in forward and reverse. Post the readings (4 readings).
Next I need to know the number written on IC2702.

PS. I might not reply soon. But tomorrow this time I will be back.

the two zener diodes
D2003 = 509 on one side. other side nothing
D2004 = 483 on one side. other side nothing

the ic number is KA7045p 6c.

May i ask you how you have decided that relay is not switching? both the sides we got around 10V DC. why you felt that it is not switching? is it becoz both sides we got the same voltage instead one side + and another side -ve?

i found another thing which i would like to tell you. the zener diode which is just below relay reading both sides same value 270 and 269 on diode checking position of DMM.
which i felt is not good.

 

The two zeners are OK.
The diode below the relay is OK too. The reading is due to the coil of the relay in parallel with the diode.
The IC number is confusing. Are u sure about the number ?
The relay need to have voltage across it. One pin should be ~0V, other can be ~ 10V ( for a 12V relay).
When you press the power switch the relay should click.
Is the relay clicking when you apply power and press power button ?

 

The two zeners are OK.
The diode below the relay is OK too. The reading is due to the coil of the relay in parallel with the diode.
The IC number is confusing. Are u sure about the number ?
The relay need to have voltage across it. One pin should be ~0V, other can be ~ 10V ( for a 12V relay).
When you press the power switch the relay should click.
Is the relay clicking when you apply power and press power button ?

yes that is the name on the IC. i found the datasheet similar name and here it is. it is a voltage detector reset IC.
http://pdf1.alldatasheet.com/datasheet-pdf/view/69421/KEC/KIA7045.html

 

Check the reset IC voltages. Look at the data sheet to see in and out.
You can use the same GND point as in #43.
Measure the pin 1 and pin 3 voltage.
Input will be around 5V.
Out is reset. I think after reset voltage will be 5v and 0V during reset period. You cannot measure the actual reset or see it with a DMM.
But the measured voltage will give me a idea

 

Check the reset IC voltages. Look at the data sheet to see in and out.
You can use the same GND point as in #43.
Measure the pin 1 and pin 3 voltage.
Input will be around 5V.
Out is reset. I think after reset voltage will be 5v and 0V during reset period. You cannot measure the actual reset or see it with a DMM.
But the measured voltage will give me a idea

Check the reset IC voltages. Look at the data sheet to see in and out.
You can use the same GND point as in #43.
Measure the pin 1 and pin 3 voltage.
Input will be around 5V.
Out is reset. I think after reset voltage will be 5v and 0V during reset period. You cannot measure the actual reset or see it with a DMM.
But the measured voltage will give me a idea

the voltages in pin 1 and 3 are 4.9v and 4.9v.

 

Does the relay respond to power sw press ?

 

Does the relay respond to power sw press ?

How do I know? I am not getting ac voltage when I on the power button. So relay is not switching on. Can I give 9v DC and see if it is clicking?