panasonic th-42px60u power problem no light

[gmzombie]

Re: panasonic th-42px60u power problem no light

sorry missed the part about plugging back in dg3. when h51 is unplugged but dg3 is plugged in no clicks. so since it didnt click after i plugged in the dg3 and disconnected the h51 the h board would be defective correct?

[Toasty]

Re: panasonic th-42px60u power problem no light

H51, yes? Not P51.

DG3 is connected, yes?

If you plug H51 back in, do the relays stop clicking when plugging it in?

Check the cable between the H51 and the G51 connector. If it's okay, then the fault is in the G board (front terminal).

Looking at the schematic, try jumping the power switch.
Pin 7 of G1 connector to chassis ground. Does the set come on?
If not, try it with the K1 plug unplugged. (other end of cable from G1 connector)

.

[gmzombie]

Re: panasonic th-42px60u power problem no light

after unplugging the p51 connector it still clicks when it is plugged in.

[Toasty]

Re: panasonic th-42px60u power problem no light

Unplug the TV.

Reconnect the DG3 connector.

See the attached photo.

Disconnect H51 from the H board (red outline).
That's the board with all the RCA and other types of input jacks on it for the set.
The connector is towards the bottom (as indicated), under the area of the panel where it is marked:

Component Video
Input
1 2

You'll have to remove that framework around and over it (one big piece outlined in green) to get to the connector.

Once it is disconnected, plug the set back in.
Do the relays click?

If not, the H board is defective.

If yes, more to check.

.

[gmzombie]

Re: panasonic th-42px60u power problem no light

yes they do click on for a few seconds

[Toasty]

Re: panasonic th-42px60u power problem no light

At this point in the testing, the P board is no longer suspect.

Unplug the TV.

At the end of the flat white cable under your hand in the 3rd picture in the first set of pics is the DG3 connection. I am not sure if there is a locking mechanism in place on that cable or connector. Some use a clip. Some use a pressure clamp. Be careful and don't pull on it until you look at it carefully.

Disconnect connector DG3.

Plug the TV in.
Do the relays click after the TV is plugged into the AC line?

.

[gmzombie]

Re: panasonic th-42px60u power problem no light

2nd half hopefully these help

[gmzombie]

Re: panasonic th-42px60u power problem no light

ok here are some pics i have a few more im posting now...it wouldnt let me post them all?

[Toasty]

Re: panasonic th-42px60u power problem no light

Could you post a well lit pic of the central back area taken on about a 45° angle from left to right? Be sure to include the P, PA, and the DT (the perforated silver box).

I want to verify something for the next step.

I'm looking for the DG connector.
I think it's on the board under the DT (box) and should have a white ribbon-style cable going into it.

.

[gmzombie]

Re: panasonic th-42px60u power problem no light

no voltage there on pin 13

[Toasty]

Re: panasonic th-42px60u power problem no light

Good.

Next:

Is there 2.7V at pin 13 of connector P25 when the TV is plugged into the AC line?

Report any voltage reading there.

.

[gmzombie]

Re: panasonic th-42px60u power problem no light

yes there is 5v dc on pin 10 in the p25 connector

[Toasty]

Re: panasonic th-42px60u power problem no light

Did some more digging.

Before you go any further with ordering...

Hook it all together and answer this question:

Is there 5V at pin 10 of connector P25 when the TV is plugged into the AC line?

[PlainBill]

Re: panasonic th-42px60u power problem no light

where is the best place to find that. i checked mouser and digikey

Google the Panasonic part number. Sears says it has been replaced with C2ABDB000110. Google that number and you will find several sources.

PlainBill

[gmzombie]

Re: panasonic th-42px60u power problem no light

where is the best place to find that. i checked mouser and digikey

[Toasty]

Re: panasonic th-42px60u power problem no light

I cannot say definitively without the unit in front of me. A power surge can mean a lot of things and do a lot of damage.

You are more than welcome to attempt the IC replacement. Do you have the tools, materials, and skills necessary? It's the 24 pin SOIC on the back of the board. ~$20 + s/h

ID: M34509G4FP
Panasonic Part Number: C2ABDB000108

.

[gmzombie]

Re: panasonic th-42px60u power problem no light

wyoming, mi is where i live. couldnt i just get the ic501 chip and replace it or is this a special chip or do you think there is more wrong on the system.

[Toasty]

Re: panasonic th-42px60u power problem no light

That matches what is printed on them, correct? There are at least 2 blue ones as I said, Pics 3 & 5 , Post 12.

My diagnosis, without having the unit to hand:
Because there are no blinks or indications from the LED, I believe the power controller MCU, IC501, is toast. That chip drives the LED when there is a power supply problem. (4 blinks) The LED also can't blink for any other problems because the chip is not allowing the other standby voltages to come on.

If you watch eBay, you can probably get a used TNPA3911 (no suffix) one from a working set for ~$70. One was up for Buy It Now until this morning for that money. Make sure you get one that has a non-DOA guarantee or at least 10 days to return it.

There are a few vendors on the net that have this for ~$120+. Most will offer a 30 day to 6 month warranty.

Where are you, by the way?
Be too funny if you were right down the street from me.

Toast

PS: Schematic of P Board attached. Hopefully someone else will chime in here.

.

[gmzombie]

Re: panasonic th-42px60u power problem no light

ok so all 3 of the resistors the 2 white ones and the blue one all have readings of .2ohms.

[Toasty]

Re: panasonic th-42px60u power problem no light

No, no...

When I say to check a resistor, I want you to use the resistance scale and compare it to the markings on the resistor. I want to see if any of them are open.

Make -sure- the set is unplugged and there are -zero- volts across them before you begin checking them. Then switch the meter to the resistance scale

In the top-down shots in Post 7, the pics 1 & 4 show one of the blue ones about 2 inches to the right of the big caps. You can see a marking of 0.22Ω, so set the meter to the lowest resistance scale and see if the reading matches or is even less than what that is marked. Do this to all the others I spoke of before.

Report any that are open... i.e.- the same as not touching the leads together.

EDIT:
You should be able to get to the leads of all these resistors without probing from the back.
You can have the board out of the set, if necessary, to check the resistors.
.