Philips 55POS9002/12 shorted mains

[Henke]

Hi.

I have a Philips tv where the two main fuses are blown. I found a bad cap. I removed it, and now it seems to work. But i have to replace the cap. I do not have the exact same one at home. What's the purpose for it and what values can i use instead?

Its placed across the Drain and Source on a N/Channel MOS

The blown one is 101K, 1KV (check picture). I have 221K, 1KV at home, can i use that?

[lotas]

This is not a fuse at all, it is a high voltage ceramic capacitor.

[Henke]

This is not a fuse at all, it is a high voltage ceramic capacitor.

I did not say that it is a fuse. that's the picture of the blown cap.

[Diah]

put 47 k 2KV or 101 but 2kv

[lotas]

I did not say that it is a fuse. that's the picture of the blown cap.

I already understood, this is a Google translator, so I translated it, but put 101 at 2kV, they often can’t handle it at 1kV...

[Diah]

I already understood, this is a Google translator, so I translated it, but put 101 at 2kV, they often can't handle it at 1kV...

who said that... LOL thought with out caps Tv can work normal....LOL over most all brands the caps for N channel at 2KV. not only that.. 47 will work better than 101, just because when you go high capacity value will generate more heat which damage the caps to brick and make short contact.

[Henke]

who said that... LOL thought with out caps Tv can work normal....LOL over most all brands the caps for N channel at 2KV. not only that.. 47 will work better than 101, just because when you go high capacity value will generate more heat which damage the caps to brick and make short contact.

Ok, thanks. But now it seems that it is more problem than i thought. 12v and 24v are not working. The chip (in new picture) that will drive the mosfet for the transformer seems to have a pulsating voltage on the Vcc, so i don't think it starts up. Any thoughts about that?

[Henke]

I already understood, this is a Google translator, so I translated it, but put 101 at 2kV, they often can't handle it at 1kV...

Ok, thanks. But now it seems that it is more problem than i thought. 12v and 24v are not working. The chip (in new picture) that will drive the mosfet for the transformer seems to have a pulsating voltage on the Vcc, so i don't think it starts up. Any thoughts about that?

[lotas]

Is this without load, are all cables connected to the power supply?

[Henke]

Is this without load, are all cables connected to the power supply?

This was without load. Only the psu board itself. Tried with all connected together, but no 12 or 24v either. Maybe do I need the PS_on/off from motherboard first?

[lotas]

Schematic

[Diah]

Ok, thanks. But now it seems that it is more problem than i thought. 12v and 24v are not working. The chip (in new picture) that will drive the mosfet for the transformer seems to have a pulsating voltage on the Vcc, so i don't think it starts up. Any thoughts about that?

12_ 24V will go high to this level only if the PS_ON signal reached the socket from MB... so as its PSU alone no MB connected... what voltage you have on the socket?

[Henke]

12_ 24V will go high to this level only if the PS_ON signal reached the socket from MB... so as its PSU alone no MB connected... what voltage you have on the socket?

Now with everything connected i only have 8,6v on the 12v socket that goes to MB. Same on the 24vA

[lotas]

Everything is correct, as it should be, 8.6 V is the output of the standby mode, when the motherboard gives the command to turn on (PS_ ON), the voltage will increase to 12 V...

[Henke]

Everything is correct, as it should be, 8.6 V is the output of the standby mode, when the motherboard gives the command to turn on (PS_ ON), the voltage will increase to 12 V...

Hmm. Maybe it’s something wrong with the MB then.


I don’t have the remote, but it should work by pushing the button in the back?
the led in the new picture is constantly flashing. Any clue what that means?

[lotas]

How many times does it blink, at intervals?

[Henke]

How many times does it blink, at intervals?

It's flashing very rapidly. It's impossible to count. But first 3 ast and then pause and then around 40 very rapidly. Then it starts over.

i tried to film in slow motion and count. its around 40, but still hard to count.

[Henke]

Ok. Now I am pretty sure that it’s flashing 3 pause, and then 40.

[Diah]

Everything is correct, as it should be, 8.6 V is the output of the standby mode, when the motherboard gives the command to turn on (PS_ ON), the voltage will increase to 12 V...

as lotas said. they will be high when PS_PN reach the PSU....
but because you had the issue at PSU.. then need to put the PSU alone on the table... and use stepdown circuit to have from 8.5V 3.3V and fed it to PS_ON... to be sure the PWM working and the vlaue will go high to 12 24V

[Henke]

as lotas said. they will be high when PS_PN reach the PSU....
but because you had the issue at PSU.. then need to put the PSU alone on the table... and use stepdown circuit to have from 8.5V 3.3V and fed it to PS_ON... to be sure the PWM working and the vlaue will go high to 12 24V

Is it enough if I connect my bench psu to PS_On?
is it 3.3v?