42pfl5432d/37 no picture but have sound

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

Yes the tv was working with the main board.
But i have sound..

I recheckd 18v is correct. But i will do it a third time.

F1 fuse is 24v on inverter main board.
Whats this 15? Another fuse..??

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

Thats the same fuse near the white legen 15 on it.
Next to it says f1 .
It gets both sides 24v

[budm]

Re: 42pfl5432d/37 no picture but have sound

'15' is the fuse code for 0.75A rating.
If you look at those white fuses that are showing 18V, if you trace out the connections, they will all lead back to 24V pins on the connector.

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

I rechecked 3rd time
It went down on all 17.8

Except the 15 fuse has 25 v now..
I will retest tomm with my other meter fluke.

I am sure numbers are correct unless my cheapo meter is f...n me.

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

The pins are getting at connector 25 v,
Fuse 15 (says f1 next to it) next to connector is 25v both sides.

All other white fuses in front of caps went to little below 18v

[budm]

Re: 42pfl5432d/37 no picture but have sound

I just look at your power supply board, I see two caps for the 24V power supply have domed tops, Can you inspect and verify them and provide clearer pictures?

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

Here are the pics voltage drop somehow at white fuses
On main inverter board. It gets 24-25 v on all 5 pins at connector

[budm]

Re: 42pfl5432d/37 no picture but have sound

The tops of those two green caps do not look flat to me.

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

Yeah but if am getting 24-25v coming in at connectir,
Thats means they are putting out.?

The voltage is dropped at 4 white fuses but not fuse 15(f1) next to connector

[budm]

Re: 42pfl5432d/37 no picture but have sound

Yeah but if am getting 24-25v coming in at connectir,
Thats means they are putting out.?

The voltage is dropped at 4 white fuses but not fuse 15(f1) next to connector

Not going to work as design at heavy load, the inverters can easily draw 5A or more. I would replace all 3 of them that is what I would do first. When cap is domed up like that the ESR will be high and the capacitance can also drop down in value too, you can also have bad cap with no sign of bulging at all but it can have high ESR.

If you look at the traces from each white fuse back to the 24V power connector, you will see it all connected through a bunch of '0' jumper (black device with '0' printed on top), to lose 6V on all 4 fuses, it means there is high resistance paths on all 4 fuses feeding lines, one way to find out is to trace Voltage from the 24V pin connector along the traces all the way to each fuse to see where the Voltage drops out occur.

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

Hi,

I played with it over nite.

There is 3 big O jumpers next to the connector.

One has 25V on both side the one closer to fuse 15.
fuse also has 25v.

The other two jumpers have 0V on both sides.

I tried heating it a touch with a fan,

I got the picture come back longer.. then it went out.
Rechecked voltage the white fuses were at 24v.

Let it cool off, after 10 min checked again they were back down all 4 white fuses down to 17V.

IT's losing voltage on the board somewhere.

I agree those 3 caps , they look suspicious, but I Dont think that's it.

I think it's the main inverter board.

Can I jump those O jumpers.. they are not getting any voltage on both sides except the one stated above.

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

Hi,

I played with it over nite.

There is 3 big O jumpers next to the connector.

One has 25V on both side the one closer to fuse 15.
fuse also has 25v.

The other two jumpers have 0V on both sides.

I tried heating it a touch with a fan,

I got the picture come back longer.. then it went out.
Rechecked voltage the white fuses were at 24v.

Let it cool off, after 10 min checked again they were back down all 4 white fuses down to 17V.

IT's losing voltage on the board somewhere.

I agree those 3 caps , they look suspicious, but I Dont think that's it.

I think it's the main inverter board.

Can I jump those O jumpers.. they are not getting any voltage on both sides except the one stated above.

how do you pop those connectors that come across from the slave inverter..
I also wanted to take it out so I can look at the back side for cracks.

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

how do you disconnect the ribbon cables, I Dont want to break something?

The ribbon comming from other inverter slave and Tcon.

I want to look at the backside of this for cracks.

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

here are pics.

[R_J]

Re: 42pfl5432d/37 no picture but have sound

Yeah but if am getting 24-25v coming in at connectir,
Thats means they are putting out.?

The voltage is dropped at 4 white fuses but not fuse 15(f1) next to connector

The bulging caps need to be replaced. If you had a scope you would see that there is likely very high ac ripple on them on top of the 24vdc. This high ripple (noise) can effect how digital circuits operate or in this case don't operate.
The flat cables pull straight out, to reinsert, carefully push them back in.

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

what do you mean pull straight out.

just pull the ribbon cable out?

how do you insert, just insert it, nothing pressing down?

[R_J]

Re: 42pfl5432d/37 no picture but have sound

what do you mean pull straight out.

just pull the ribbon cable out?

how do you insert, just insert it, nothing pressing down?

Straight out, in the direction the flat cable is coming out of the connector, There are no latches on these connectors, the flat cable is held in by the internal electrical contacts alone. They go back in the same way they came out.
grab onto the blue part of the flex cable, it is a stiffener to prevent the cable from bending when reinserted

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

got them

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

Is it safe to say I got bad main inverter board.???



Are those O points "jumpers" all 3 have to have 25V all the time.

Only the top has 25V both sides.

[dsm482]

Re: 42pfl5432d/37 no picture but have sound

Where do I find inverter board Master only.

Not to many around on internet