Panasonic TH-42PZ85E --> Completely dead!

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

When i ground the cable to the speaker housing the picture on scope is the same

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

Needs to be grounded to the chassis.... Fan mounts work well I've found

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

So what do you think of the pictures?

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

If you see that, you haven't got a good ground.

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

The 3rd picture is the default setting when scope is on. LAst pic is when i put the probe to pin 11/12/13

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Your right, pin 11/13 the line is horizontal but 1 square higher.
On pin 12 its default horizontal line

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

Is it on 5V/div or 1V/div?
For 1V/div you may need to move the trace down a little using the V POS control.

You should now check AC DET signal, MC501.

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Its on 5v/div. I took a picture of the setting so you can see by yourself.
First picture of the scope setting is on 1V/div

Then you asked me to change it to 5 and thats the last picture. The horizontal line is going 1 square upwards. ( Means 5v right? )

How do i test AC DET signal? Where do i put the probe?

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Again 2 pictures.

First is pin 12
Second is pin 11/13

If i change the time/div it just slows down the signal ( visually).
Vpos is set to the middle.

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

AC_DET is on pin 16 of MC501... look at the schematic...

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

I searched for ac det but i did not find it sorry.

With pin 16 i get this on the scope

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

Ok, this means the AC detection is working... So... this is where I draw a blank. Did you try bridging MC552 standby switch?

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Ok thats good. Not yet , was thinking i did it all wrong but I'm glad i did it right

Does it matter if its pin 11 or 13?

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Btw , scope is a good way to measure! I'm really surprised!! What do you see at the last picture? Its starting at 5v dropping to 0v?

So if I'm correct its just a way to measure if the DC line is working throughout the PS?

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Ill start with Pin 11 , standby on.

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Pin 11 bridged to P25/Pin 9 did not do anything.
Pin 13 bridged to P25/pin 9 does not turn on the TV but there is something happening.

I used the multimeter to test the 5V STB on diode. ( Pins were connected the whole time ).
I bridged pin 13 to pin 9 and the 5V dropped to 0.8v and i hear something ticking real soft , sounds like a old clock that you wind up. ( tickticktickticktick ).

No power/clicks/led!

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

Sounds almost like the 5VSB may be shorted on the main board... That would be odd...
Maybe try powering 5VSB from a lab power supply separately?

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

5v STB on P25/Pin9 or Pin12 on MC501 or directly on main board? So your now thinking power supply is ok?

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

I don't know, I'm just brainstorming right now.
Try keeping power board disconnected, just feed in 5V, and set a 1 amp current limit.

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Ok will do that tomorrow.
Thx , and if you have any idea's let me know!