Home Theater Forum and Systems banner

Hitachi P50H401 led flashes 3 times.

119547 Views 320 Replies 37 Participants Last post by  georugby
I just picked this tv up today 50 dollars. In the power supply the two caps are swollen like my p50s601. One of the driver chips on the lower sdr board is burnt. If i unhook the sdr board then the tv powers up with the top half working. I am going to replace the two caps in the power supply and look into ordering the lower sdr board. in my p50s601 It was the top sdr that was bad now this one its the lower one. everything looks the same as the p50s601.

If you have this model check out my other tread with info about this model. http://www.hometheatershack.com/forums/hitachi/30302-p50s601-blue-power-light-flashing-3-times.html

click this link to see about the sdr boards and how to test the chips if you dont see burnt ones. http://ww2.justanswer.com/uploads/OriginalSeadog/2009-11-26_232005_DW3BufferICs.pdf

click this link for the trouble shooting flow chart. http://ww2.justanswer.com/uploads/O...55402_P50H401_Trouble_Shooting_Flow_Chart.pdf

another link showing you how to trouble shoot the sdr http://ww2.justanswer.com/uploads/O..._Trouble_Shooting_DW3-no-pix-troubleshoot.pdf


This wont let me update the title. I forgot the H in P50H401
See less See more
281 - 300 of 321 Posts
Ok so i switched the Caps and Same issue, so i went on to take out a Buffer Board at a time, when i took out the bottom Board SDR-D the top of the screen would light up and stay on with out the blinking light and then would go to stand by (im thinks cause theres nothing connected to it) does this mean that i have to swap out my buffer board? im thinking of ordering them today so they will be delivered by sat. Thanks.
PS: When i took out the top board and left the bottom one the TV would go in to safe mode blinking 3 times.

When the top was on it had those crazy lines across, should i just replace both?
The lines are probably a connection problem. You may need both but I doubt it.
theres no marks on either one of the boards, could the bottom one also be connections since none of the disks are damaged?
I doubt it, but hard to tell not being there to observe and test.
ill just replace them both. Thanks, will post more once i get them.
Good news it's been a month with no issues. :) That guy must know what he is doing with those SDR boards.

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.


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.
I not only have the black bars but I have green tint and green bars anywhere letters are on the screen. I have been fiddeling with the flat wires in the back for some time now and and at the point where I'm ready to give up. Any tips?
Black bars are most likely incorrectly installed or damaged cables. The green may indicate alignment needed. Start with the dc voltages. Alignment beyond that reuires a scope and experience.
I'm trying to test the SMD with a multimeter but I don't know what setting to use DCA, DCV, ACV etc....

When I unplugged the SDR board on the top and left the bottom plugged in I turned the TV on and the blue LED did not flash this time. But the screen was still black. It did the same when I left the bottom and unplugged the top. Any ideas?

Jason1976 wrote:
You can test the sdr boards with a multi meter. one of the links i have posted tells you how to test them for resistance. if they are shorted out they will max out. They should show like 500 to 700 ohm if good. some of them you have to test backwards because they show no resistance. Also double check the power supply for those two capsitors that get swollen. They are the ones that seam to go out in this model and need replaced.

Read more: Hitachi P50H401 led flashes 3 times. - Page 2 - Home Theater Forum and Systems - HomeTheaterShack.com
Most checks that I have seen have been resistance checks, for which you would use an Ohms setting. If you are testing semiconductors you can use that and/or the diode check that most multimeters have. What SMD are you checking, specifically?
I am checking the SDR Logic and Ysus board on my P50V701 Hitatchi. I replaced the capacitors that were puffy. Still nothing on my television, however, the blue flashing LED do not flash at all. It's a solid blue but than switches over to a solid standby mode.

I bought a 7 Function CEN-TECH Digital Multimeter for $5 at Harbor Freight and can't figure out how to test the SMD from Jason 1976 post on page 4 on how to test the SMD with a multimeter. I can't figure out where to switch the dial on my multimeter to test the SMD. It has DCV, ACV DCA,10A, hFE, ohms setting on it. Any help?
If you want to measure resistance use the ohms setting. When you refer to a post, refer to the number, not the page. People may use different page settings for number of posts displayed.
Post #18 is what I am referring too. Sorry. I guess what I am wondering is if I would test it at 2000 or 200 and do I make sure I touch them with both leads?
2000. Yes, both leads.
How do I know they are shorted out? Does it matter what lead goes on which side? Is it 2000 or 2000k? I seem to have sketchy numbers that jump around from 100 and something to 334 to 500 all in the same check.
The direction does not matter if you are measuring resistance and not a semiconductor. It does for a diode or transistor. I assume you are measuring across the capacitors. Since capacitors charge and discharge, you will not get clear resistance measurements, but if you are not getting close to zero ohms you don't have a short THERE. You could have one somewhere else.

The post referenced and these checks are a specific check for one specific problem. If you found a short there you have actionable information. If you don't it does not mean that the board is good.
They seem fine except for a few on the SDR-U board. I get reading that are -1200 and 23 on few of them. I removed the orange ribbons from the SDR-U and left the SDR-D board in and turned the television on to no aveil. I reversed the procedure and still nothing. However, the blue led stayed on in both instances but the screen was still black. The first time a powered the television after replacing the capacitors the sound came on but it turned off right away. No blinking blue light. From reading the posts it seems as though the SDR boards might be the problem??? I would rather spend $300 to replace the boards than spending $1200 on a new television. Either way I am gambling....
Okay I have been trying to Figure this tv of mine out for quiet some time. I have a new lower board. New capacitor. When I connect the 3 flat wires to the board they seem to go in easy and fine. But no matter how much I fiddle with em I can't the picture to look any better than the pics I have included . Is it possible I'm over looking something? I had the same board and capacitors go out on a different tv but same model and when I put that one back together it worked with no problem. Any help would be much appreciated. Maybe one of you gurus lives near by or know of someone that can fix this for cheap....like really cheap haha.


See less See more
Looks like a signal processing related problem. What was the original symptom?
It was 3 blinking blue lights. It's so frustrating. The previous tv I had had the same issue and I got it all fixed and working great for over a year. Then I got deployed to the sand box for 3 months and came home to am empty robbed apt. Got this tv from a guy thinking no problem and it's kicking my @$$. Haha. I must have been lucky with the first tv. How do I check to see if it's signaling issues
281 - 300 of 321 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.