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Discussion Starter #1 (Edited)
I think its the Y sub board. or am I wrong? I found into online that says when this happens it's the Y board.

powr light flashes 2 times and then pauses then flashes 3 times over and over again. only flashes twice once then after that it's the 3 flashes over and over again. when i unplug it and plug it back in standby comes on. then i hit power the screen comes on for a few secs then it goes off and the power light starts flashing.

I was reading on a web page that when it flashes twice then its the x board and if it flashes three times it's the y board.

only found that info on one page. i want to make sure it's right before i order the part.

other web pages ware saying the x board. so i want to make sure that 3 lights means the y board. or do i go by the first set of two flashes?

 

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Flashing LED codes are just a start to determining the actual problem. It could be a YSUS, or it could be a related problem. It could also be a buffer shorted that damaged the YSUS. PDP troubleshooting is complex and while you might be able to fix it with simple board swapping, I have to warn you that many techs have been burned by this method.
 

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Discussion Starter #3
I popped the ribbion flat cable off the x sub and then the tv doesn't do it. the power stays on longer but after so long it shuts down to standby mode. if i pull the ribbion flat cable from the y sub it starts out with the 3 flashing lights and skips the two flashing lights. It's making me wonder if its something to do with the x sub since it starts out with the blue light flashing twice. the board that the ribbion cables run to have two BGA chips. I am wondering if it couled even be that logic board part number JA08521. I thought about tring to put a little pressure on both of the BGA chips in case its another broken solder issue.
 

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Not all problems are the same. It is not likely that this is a logic board problem and messing with BGA chips that don't have a problem is a good way to create one. There is simply no substitute for getting the manuals and documentation and doing troubleshooting.
 

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Discussion Starter #5
true. I wish i could just find someone selling all the boards from one with a broken screen. then i could just switch them all.
 

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Ebay, craig's list, parts-link.com are all possible places to find something like that. You might also check with the local service shops. Some will buy cracked sets for the boards.
 

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Discussion Starter #7
Ebay, craig's list, parts-link.com are all possible places to find something like that. You might also check with the local service shops. Some will buy cracked sets for the boards.
I already checked eBay and craigslist. but i didn't know about parts-link. i see boards by themselves on eBay but not a full set of boards. thanks for the parts-link.com link.
 

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Discussion Starter #8
I went ahead and opened the set to take a look. Two caps on the power supply are swollen and puffy on the top. They are both 3300uf 100v 105c . They supply power to the x sub and then the x sub supplies power to the y sub boards. I am wondering if the power supply is putting out the wrong voltage and if it's getting a voltage drop. It maybe turning itself off to keep from burning out the boards. I ordered replacement caps this morning. I will give an update if this helps the set.

They have a rubber glue on them. Gluing them to other caps. I think its going to be fun getting them removed.
 

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Slice the glue with an exacto knife and change the swollen caps. It may be all that is wrong. If not, you have not lost much as caps are cheap.
 

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Discussion Starter #10

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Discussion Starter #11
No luck with the replacement caps. It looks like i will have to replace the x or the y board. I am going to start with the y board.
 

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Discussion Starter #12 (Edited)
I just tried something. If I unhook the one sdr board the tv powers up and stays on but if i leave SDR-U hooked up then it shuts down and starts with the flashing light. If i remove this one then the tv stays on. It makes me wonder if the issue is this SDR board.
 

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Discussion Starter #13 (Edited)
Ok I think its my SDR-U board. None of the chips look bad(no holes or burned areas) but they test bad.

http://ww2.justanswer.com/uploads/OriginalSeadog/2009-11-26_232005_DW3BufferICs.pdf

look at this. The Ohms go to 0 on 3 of the 8 chips on my SDR-U board. They all test fine at around 800 Ohm on my SDR-D

I also found this and from what i see a lot of the parts are compatable with mine tv.

http://ww2.justanswer.com/uploads/OriginalSeadog/2009-11-27_155402_P50H401_Trouble_Shooting_Flow_Chart.pdf

This next one has my tv listed.

http://ww2.justanswer.com/uploads/OriginalSeadog/2009-11-27_194320_Plasma_TV_Trouble_Shooting_DW3-no-pix-troubleshoot.pdf

Is there something i should check on my Y sub to make sure it wont happen again? I already replaced two puffy looking caps on my power supply. I guess i should go by the trouble shooting guide and test voltages or am i better off to replace the y sub at the same time. like i said before if i unhook this sdr board the tv stays powered up longer before turning itself off to a red led on the front. with the board in it goes right into protection mode and starts the flashing blue LED.
 

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Discussion Starter #14 (Edited)


I think I need to replace both sdr boards. I was reading that sometimes when you mix them this is what happens.

hitachi has a new part number for them now. The chips arnt the same brand.

http://ww2.justanswer.com/uploads/OriginalSeadog/2009-11-26_232005_DW3BufferICs.pdf

this here says if you mix the sdr's

Note: Mixing P50H401 and P50H401A SDRs will cause an unusual (distorted) picture. I order the lower sdr. to replace the stock one I have.
 

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That symptom does not make sense to me with respect to the upper and lower buffers. If there is a difference you would expect a clear image difference between the top and bottom.
 

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Discussion Starter #16
I am thinking since they don't have the same chips it's making it have a distorted video. The bottom is worse then the top for the lines. I will take a photo with the antenna hooked up. all inputs are the same. shows up on menus and all. I am thinking its something to do with the buffers, or something with the y sub since its going side to side and not up and down. Before replacing the SDR-U the tv wouldn't power up. I would get the 3 flashing power lights. I am thinking it could even be an issue with the y sub.
 

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Discussion Starter #17 (Edited)
Ok it works. Never mind i had to reseat the cables for the sdr boards. The lines are gone. I had to redo them a few times each to get the lines to go away. Now the video is clear and it works great. I replaced the two 100v 3300uF caps on the power supply that were domed at the top, and then replaced one of the SDR boards to make the tv work. I am thinking the bad caps in the power supply put out the wrong voltage, and made the chips go bad on the one sdr board.
 

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Discussion Starter #18 (Edited)
It's still working great. with no issues. someone just listed one localy on my craigslist with the same issue 3 light flash. I sent them an offer of 50 dollars. I will see if they take it. It's almost the same tv a P50H401

update I picked up the tv and when I plugged it in I think its flashing 4 times in a row but it could be that the tv is cold. I found out it has a bad sdr board. I am uploading a video on youtube.
 

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Discussion Starter #20
I also wanted to add an updated to this. It looks like Hitachi 50PD9800 also has the same issue with the two caps on the power supply going bad and burning out one or both of the sdr boards.

http://www.hometheatershack.com/forums/hitachi/44286-black-horizontal-lines-hitachi-50pd9800.html

p50s601 p50h401 and p50pd9800 all had the same ND60200-0047 on the sdr-u board. The p50pd9800 is almost the same as the others.

This guy had issues with black bars on the video that is caused by the ribbon cables on the sdr boards not being right. I had the same issues with mine. I kept turning it off and back on doing one cable at a time until i found what one was making it happen.


after looking at the pdf files i have listed it looks like P42H401, P42H4011, P50H401, P50H4011, P55H4011 and P55H401 and P42T501,
P50S601, P50V701, P50X901, P50T501, P55H401, P55T501 and P60X901 Plasma Televisions. May have the same issues.
 
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