Panasonic TC-P50s2 7 blink problem

[Gies40]

Re: Panasonic TC-P50s2 7 blink problem

TW, I just got around to taking a look at the components that are in the repair kit. Now I understand why you said to use those components as a "Guide."

Without looking at those specific components on the SC I assumed it might be easy to replace those components. Now that I've looked, forget about it! I don't know how anyone could successfully change those components, particularly the ultra small resistors and the IC. Praise to those who can do it - they have far superior soldering skills than I do.

I'll be watching for an SC board on-line.
Thanks again for the help. . .

[tw2005]

Re: Panasonic TC-P50s2 7 blink problem

I was actually hoping you'd have a probe and see if any of them had shorted.

not impossible to fix, but patience,determination, plenty of light, magnification and a couple of soldering irons, flux pen is all I had.

Ebay maybe an option

[Gies40]

Re: Panasonic TC-P50s2 7 blink problem

I looked on the reverse side of the board and got a little confused - particularly on the IC. There aren't as many solder spots as there are legs on the IC and I don't know what IC leg does what. I have to learn a little more about the transistors in order to know how to check them also . . . can you check them and the resistors while they're connected to the board?

I'll probably end up buying a board and then experimenting with repair on the old one.

[tw2005]

Re: Panasonic TC-P50s2 7 blink problem

for shorts you can check, I am curious to see if you can find any of those parts or transistors shorted only.

[Gies40]

Re: Panasonic TC-P50s2 7 blink problem

TW, I'm lacking knowledge on doing that. How do I do that with the transistors? They have three legs - across which ones am I testing to make it meaningful?
How about with the IC?
I know I'll want to look at the wiring diagram but I'm not sure what I'm looking for.

With the resistors I can measure both sides.

I just need some direction and guidance.
Thanks,

[tw2005]

Re: Panasonic TC-P50s2 7 blink problem

diode mode and any 2 pins, all combinations. generally the IGBTs will be short acros all 3 legs. The IC bit hard, most of mine were shorted across the Vcc and gnd which is the 15V line into the board but what you measured seemed ok. Not sure what to make of it, i'm hoping it's the SC which it should be but i have a vague memory of someone who may have had a 7 blink end up being a SS board but that's unusual. can't rememeber enough to find the post some time ago now and I could be totally off track thinking that.
resistors won't always read their value in cct and to be expected.



I'm hoping you find one of those transistors shorted or something just to confirm something faulty on the board.

[Gies40]

Re: Panasonic TC-P50s2 7 blink problem

Thanks TW, that helps. I'll give it a try over this weekend.

[Gies40]

Re: Panasonic TC-P50s2 7 blink problem

I've been out of touch for a couple weeks.

Getting back to measuring the transistors, etc. . . I know just a little about transistors but lately I've seen some article warning that a person could damage transistors if not done properly - it didn't give much detail. I searched further but got more confused and they weren't talking about anything specific to my TV anyway. Can you give me some guidance? I think my multimeter has a range for diodes/transistors is that the protection or is there more I need to be concerned about?

Thanks,

[tom66]

Re: Panasonic TC-P50s2 7 blink problem

It's probably talking about ESD... in which case that only applies to handling transistors.

[Gies40]

Re: Panasonic TC-P50s2 7 blink problem

I finally have measurements from most of the repair kit components - measured in circuit.

The transistors all measured "open" in all directions.

Having three pinouts the diode (D482) looks more like transistors than a diode. They measures "short" in one direction - I assume that is expected.

Resistor R551 measured 10.5ohms I never found resistor R451. I'll have to get the mag glass on it.

[tw2005]

Re: Panasonic TC-P50s2 7 blink problem

Use the service manual pdf search bar. For locating components on the PCB print search R451, you'll find it opposite Q451 on the other side of the heatsink 5.6 ohm. To find in the schematics add the cct board prefix 16, i.e. R16451