JVC 49cf890 - Fire TV - no picture but sound

[dskall]

Re: JVC 49cf890 - Fire TV - no picture but sound

Vone test at the round spot or caps next to it. The other is just fuse designation.
Vone around 25v. Test both side of fuse with N on it for 12v

[lotas]

Re: JVC 49cf890 - Fire TV - no picture but sound

Voffe - 0V
Vss - 0V

Cannot find Vone and VCC AVD. Found VONE here but not sure which point to measure:


Also found few Vcc point but not AVD.

On this 32V point i have got 0V

32V is not a dot, this is the designation of a standing fuse ("N" - 32v at 5a)

[Dobsuk]

Re: JVC 49cf890 - Fire TV - no picture but sound

Vone - 0V

All Vcc points are with the correct voltage. +- 0.1 but maybe because of my multimeter. For example Vcc_1.6 is 1.7 on my meter.
1.05 -> 1.1
1.8 -> 1.8
3.3 -> 3.2

[lotas]

Re: JVC 49cf890 - Fire TV - no picture but sound

I wrote to you, check, ring all ceramic capacitors with a multimeter for a short circuit.

[Dobsuk]

Re: JVC 49cf890 - Fire TV - no picture but sound

I wrote to you, check, ring all ceramic capacitors with a multimeter for a short circuit.

I did that already. No shorts...

[dskall]

Re: JVC 49cf890 - Fire TV - no picture but sound

Vone is important voltage. If it is not there you will have no picture.

[Dobsuk]

Re: JVC 49cf890 - Fire TV - no picture but sound

Vone is important voltage. If it is not there you will have no picture.

So, i checked it few times - it is not there

[lotas]

Re: JVC 49cf890 - Fire TV - no picture but sound

So, i checked it few times - it is not there

Is there tension at these points?

[Dobsuk]

Re: JVC 49cf890 - Fire TV - no picture but sound

Is there tension at these points?

No - 0V

[dskall]

Re: JVC 49cf890 - Fire TV - no picture but sound

Maybe you can list your voltages so we don't have to hunt though posts to figure out what voltages you have and what are missing.

[Dobsuk]

Re: JVC 49cf890 - Fire TV - no picture but sound

Voffe - 0V
Vss - 0V
Vone - 0V
Vcc_1.6 -> 1.7
Vcc_1.05 -> 1.1
Vcc_1.8 -> 1.8
Vcc_3.3 -> 3.2

[dskall]

Re: JVC 49cf890 - Fire TV - no picture but sound

There also is an AVVD test point on left side of your main chip.

[Dobsuk]

Re: JVC 49cf890 - Fire TV - no picture but sound

There also is an AVVD test point on left side of your main chip.

Excuse my incompetence but i cannot see any AVVD test points

[dskall]

Re: JVC 49cf890 - Fire TV - no picture but sound

Post #35 first picture between label and caps look like AVVD. If you have no voltage there, I would say you have a bad power chip.

[Dobsuk]

Re: JVC 49cf890 - Fire TV - no picture but sound

Happy New Year to all. Sorry but I was away for few weeks.

Post #35 first picture between label and caps look like AVVD. If you have no voltage there, I would say you have a bad power chip.

AVVD - 1.7V

[Dobsuk]

Re: JVC 49cf890 - Fire TV - no picture but sound

It will be sold as spare. Thank you all.