panasonic 42 inch viera TH-L42U20Z-no picture

[dvsguy]

hey guys have a panasonic 42 inch viera TH-L42U20Z with 7 red blinking lights of doom, can anyone help me with this ?

[Andrew F. Ali]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

I think 7 blinks with the Panasonic Plasma means a SC fault...That is the board on the LEFT when looking from the back of the TV.

[dvsguy]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

I think 7 blinks with the Panasonic Plasma means a SC fault...That is the board on the LEFT when looking from the back of the TV.

Is that the master inverter board ? bugger thats the one i just replaced

[Alastair E]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

Nah--No inverters or backlights in any plasma sets...

What you have are two Sustain boards, the SC/SN is on Lt hand side, the SS is on Rt hand side.--NO Inverters--Thats LCD Junk!

Plasma is Completely Different Technology to LCD crap--Forget anything to do with LCD sets when working on Plasmas.....

SC type board has separate buffer-boards to the panel--but I suspect yours is an SN with the buffer-chips directly fitted to it, ie all in one.
--IF you replaced it--Did you test/check the SS board as these can kill a new SN instantly.....

Pictures of these boards will help ID them and the way forward.

[flocko]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

TH-L42U20Z is a LCD set not plasma ? not sure there is a blink code for these If i am right it uses an LG panel and inverters

[dvsguy]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

Nah--No inverters or backlights in any plasma sets...

What you have are two Sustain boards, the SC/SN is on Lt hand side, the SS is on Rt hand side.--NO Inverters--Thats LCD Junk!

Plasma is Completely Different Technology to LCD crap--Forget anything to do with LCD sets when working on Plasmas.....

SC type board has separate buffer-boards to the panel--but I suspect yours is an SN with the buffer-chips directly fitted to it, ie all in one.
--IF you replaced it--Did you test/check the SS board as these can kill a new SN instantly.....

Pictures of these boards will help ID them and the way forward.

This is the board i replaced as last guy tried to fix it an fried it, it goes on far left of tv which is circled red

[flocko]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

As in my post above, your set is an LCD model,and that is the back light inverter board,I would start by checking the fuse on the board (just above and to the left of the white connector) Flocko

[Andrew F. Ali]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

OK...So I really thought this was a PLASMA.....Do you know how to self test the Pwr Bd? If I see a clear pic of the connector underside that goes to the Main Bd, I could tell you how.

[Andrew F. Ali]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

As in my post above, your set is an LCD model,and that is the back light inverter board,I would start by checking the fuse on the board (just above and to the left of the white connector) Flocko

OK...So I really thought this was a PLASMA.....Do you know how to self test the Pwr Bd? If I see a clear pic of the connector underside that goes to the Main Bd, I could tell you how.
Check that fuse flocko asked about.

[dvsguy]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

As in my post above, your set is an LCD model,and that is the back light inverter board,I would start by checking the fuse on the board (just above and to the left of the white connector) Flocko

Cool thank you, so just test with multi-meter make sure current is going through and fuse not blown ? i replaced the whole inverter board with 1 i brought off ebay

[dvsguy]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

OK...So I really thought this was a PLASMA.....Do you know how to self test the Pwr Bd? If I see a clear pic of the connector underside that goes to the Main Bd, I could tell you how.
Check that fuse flocko asked about.

cheers man, not really sure how to self test ? which connecter do you mean ? sorry bit of a noob

[Andrew F. Ali]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

The connector that goes to the Main Bd....the one with PS-ON...StdBy....and etc

[dvsguy]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

The connector that goes to the Main Bd....the one with PS-ON...StdBy....and etc

This one Andrew ?

[tw2005]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

This one Andrew ?

Please be aware what you have highlighted is 240V mains power which can kill.

Ali has referred you to the main AV board which will only have non lethal low DC voltages present.

This is a 2010 series model and although I can't find a manual you may be able to piece some info from other regions models.

7 blink could be a main board issue, sub 3.3v if this training guide is close.

I would use U22 or U25 fault finding trees.

may be worth looking at the chinese model, it has 7 blinks in its list of errors.

[Andrew F. Ali]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

Ali has referred you to the main AV board which will only have non lethal low DC voltages present.

Yes, Sir...I am referring to the Main AV Board.

[vinceroger69]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

ive highlighted the connector is there any writing next too these pins on this connector some times its on the underside of the board if not your going to have to use the schematic etc so you know what the voltages should be on each pin etc

[dvsguy]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

ive highlighted the connector is there any writing next too these pins on this connector some times its on the underside of the board if not your going to have to use the schematic etc so you know what the voltages should be on each pin etc

I have taken pics of both side of board you are talking about

[dvsguy]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

Ali has referred you to the main AV board which will only have non lethal low DC voltages present.

Yes, Sir...I am referring to the Main AV Board.

So you are talking about the main AV board ? is this the one in the pic below ? this is the faulty one i replaced, which connector do you want pic of ?

[vinceroger69]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

post 16 right hand board is the main av board the board in the above pictutre is the invertor board

[dvsguy]

Re: panasonic 42 inch viera TH-L42U20Z-no picture

So left this tv on backburner but any ideas, what to test, isolate ???? did you see pics of pins you were after ? any help greatly appreciated.