Samsung 42" Plasma PN42C450B1D

[fatcattara]

Re: Samsung 42" Plasma PN42C450B1D

I do have a multimeter available

[tom66]

Re: Samsung 42" Plasma PN42C450B1D

Great, can you see if you can test the VS voltage from the power board, with everything as it currently is? It should be around 200V. Red probe on test point, black probe can go on the metal chassis for ground.

[fatcattara]

Re: Samsung 42" Plasma PN42C450B1D

Is that from the big pin on top of the power board? If so - it's 0V

[fatcattara]

Re: Samsung 42" Plasma PN42C450B1D

See picture for test point used to chasis

http://i34.photobucket.com/albums/d1...ps2995753b.jpg

[tom66]

Re: Samsung 42" Plasma PN42C450B1D

That's the correct point, so, does that change at all as the TV clicks on and off?

[fatcattara]

Re: Samsung 42" Plasma PN42C450B1D

no, it did not

[tw2005]

Re: Samsung 42" Plasma PN42C450B1D

try this, remove power cable from ymain CN5000 or CN804 at PSU. Have the probes connected, then try again. It may come up briefly and then disappear.

[fatcattara]

Re: Samsung 42" Plasma PN42C450B1D

Once I removed the x/y power cable, the green LED stayed on, the relay just clicked once and the Voltage went up to 209V and dropped down to less then 1 V

[tw2005]

Re: Samsung 42" Plasma PN42C450B1D

looking very much like almost every other one of these with an xmain failure. On the Xmain, there's a single heatsink. The outermost transistors either end marked XS,XG ( the other numbers are too small for me to read) set the meter to continuity and probe across any 2 legs of both of those and tell me if they are shorted.

[fatcattara]

Re: Samsung 42" Plasma PN42C450B1D

non of them were shorted - I plugged the left High voltage board to the power supply (kept the one on the right off) and when the relays cycled, the voltage went up to 200V

[tw2005]

Re: Samsung 42" Plasma PN42C450B1D

Well even though they're not short, could be something else on the Xmain, you've had a clear change. You could always hook it back up and repeat the vsus check and confirm multiple clicks and nil voltage showing at all ever.

then the hard bit is what to recommend. I took the least risk higher cost option of purchasing the 3 boards because they are really cheap to get and I've read y's being killed by the X and I'm pretty sure I stuffed my y trying to repair the X.

My buffer was ok which I checked with the replacement so i could have skimped there.

The 3 at SJ are about $90 but i got mine through payless components and got them much cheaper.

that was last year, not sure if he still has any or how cheap.

See what Tom reckons, some progress made.

[fatcattara]

Re: Samsung 42" Plasma PN42C450B1D

Thanks for your great help - have a g'day mate

[tw2005]

Re: Samsung 42" Plasma PN42C450B1D

Thanks for your great help - have a g'day mate

Ha, Ha.

I might go and put a kangaroo on the BBQ. (joke)

[Lokidoki]

Re: Samsung 42" Plasma PN42C450B1D

Hello. I am having a similar issue with the same model television. Samsung PN42C450B1DXZA.

It worked perfectly for years but just recently I went to turn it on and I just hear a few clicks as if it is trying to turn on, then just stops. Never any sort of picture or sound. I have researched a tiny bit and it seems Samsung plasmas are notorious for bad capacitors? I have never seen bad capacitors. Should testing for those be my first step? How do you tell that a capacitor is bad? Is it warped or something? If someone wouldn't mind giving me some pointers there I will take it apart and check her out. It's been unplugged for a couple weeks at least.

[Lokidoki]

Re: Samsung 42" Plasma PN42C450B1D











Sprry about the blur on a couple of them. Took it apart and checked it out. Again, idk exactly what a blown capacitor is supposed to look like, but I didn't notice anything that looked burned or warped or destroyed on any of the boards. Are there certain ones I am supposed to be checking for? Am I just missing it?

So assuming it isn't a capacitor issue, what else could cause the problem? I will update shortly with a video of what happens when I try to boot the TV up. I am about to go and re-seat all cables and check again for anything that looks out of the ordinary and then will plug her back up to record.

[Lokidoki]

Re: Samsung 42" Plasma PN42C450B1D

https://www.youtube.com/watch?v=17nZEFpaKnw

This is me trying to turn it on, getting a blinking light and clicks. I then try to use the remote and only get a slight blink of the light when I hit the power key.

[selldoor]

Re: Samsung 42" Plasma PN42C450B1D

Lokidoki
There is a whole thread on what bad caps look like
https://www.badcaps.net/forum/showthread.php?t=424

Next you need to start reading this thread from the beginning and do some of the tests
reporting the test and result.
When removing boards or cables switch off and unplug and leave 15 minutes or so between each plug in.

Also if you click on troubleshooting tvs and video sources above in the stickies there is a good guide by Tom66 on how to test a plasma tv
https://www.badcaps.net/forum/showthread.php?t=18542&

[Lokidoki]

Re: Samsung 42" Plasma PN42C450B1D

Sorry I don't see that sticky, only the LED/monitor sticky by someone else. Will search for that thread now.

[lemo5617]

Re: Samsung 42" Plasma PN42C450B1D

Hi i have the same model and my problem is black horizontal lines on the middle of screen...should i change the buffer board...

[juke175]

Re: Samsung 42" Plasma PN42C450B1D

Hi guys, Newbie here. First of all, many thanks for your help! I also have a Samsung PN42c450b1d, model code pn42c450b1dxza. The upper 1/3rd of the screen is dark. The bottom 2/3rd of the screen is fine. All functions (sound, etc) work fine. Any suggestions? Thanks in advance for your help!