Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

No a USB scope will not be suitable. An old analog scope, 50MHz dual channel or more, is suitable, and can be had in many cases for under $50.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Ok, thanks for the info. My budget is almost nil right not so I'll see if I can find one to borrow until I can afford it. I'll consider the CRT hack to be insufficient too.

I wish I knew Hitachis were such a pain to diagnose before I bought this thing. Live and learn.

Thanks, again, for the help.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

I got a response to a craigslist post asking for an oscilloscope for sale and someone's got a Type 317 Oscilloscope. Anyone have any idea if this would work to test plasma TV boards? It sure looks cool but I think it's only a 10mhz scope.

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Not really worth it for any more than $15. Would be difficult to get the probes for it due to non BNC connectors, etc.
This video shows how to get a cheap scope ($50 or less) from eBay:-
http://www.youtube.com/watch?v=lZfbo-2sd1A

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Thanks, I figured 10Mhz was probably too low & wasn't even thinking about about finding probes for it. Thanks, again, for the link on finding cheap oscilloscopes on ebay. I found a Tenma Oscilloscope 60Mhz 72-5025 on craigslist (no shipping). Would 60Mhz do the trick?

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

60MHz is fine. Dual channel? Tenma is just a rebadge, but most rebadge scopes are fine.

When you buy a scope, bring a probe with you or ask to borrow one. Hook the probe off the CAL TEST point and you should get a good clear square wave when on about 1ms/div, 500mV/div, DC coupling, norm trigger.

Line and TV triggers are extremely useful for plasmas, so if this scope has them, then even better.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

According to the photo below it looks like there are Auto, Norm and 2 TV Mode Triggers and Ch1, Ch2, Line and some other Source Triggers. I just hope the guy answers my email.

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Looks decent, as long as it works, will be good for you.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Thank you, tom66, for motivating me into getting an Oscilloscope. I contacted the guy with the scope. He wants $40 and I'm going to get it tomorrow, hopefully. Is there anything I should brush up on in the meantime, i.e. video tutorials, "How to test components with an oscilloscope" tutorial, etc.? I've found some but thought others might know better ones.

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Before you get it, ask to borrow a probe and hook it to the CAL output to test it (you should see a square wave), if the guy is worth his salt he can show you how to test it.

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

A nice tutorial: https://www.youtube.com/watch?v=SxZWcku_Sw0

[Videojoe]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

I just fixed a hitachi with the same problem. First I replaced the 450v caps on the power supply board because they were puffy. I also replaced some of the other caps that usually crap out. Then I disconnected the y scan buffer boards one at a time with the power off. These are the ADM's I guess. They are the two long skinny boards that run down the left side of the display. When I disconnected the upper board, the tv powered up and the lower half of the screen lit up. So I plugged the upper board back in and the tv wouldn't power up. Verified the bad board by reading almost zero ohms across the chip caps next to 2 of the ICs. I replaced the upper board for $60 and bam. All is good.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

I just fixed a hitachi with the same problem. First I replaced the 450v caps on the power supply board because they were puffy. I also replaced some of the other caps that usually crap out. Then I disconnected the y scan buffer boards one at a time with the power off. These are the ADM's I guess. They are the two long skinny boards that run down the left side of the display. When I disconnected the upper board, the tv powered up and the lower half of the screen lit up. So I plugged the upper board back in and the tv wouldn't power up. Verified the bad board by reading almost zero ohms across the chip caps next to 2 of the ICs. I replaced the upper board for $60 and bam. All is good.

Thanks for sharing your experience. Did your TV's blue front power LED blink 5 times? With mine all the caps and voltage outputs look good - albeit briefly before it powers off into safe mode. Frustratingly I have disconnectted every board one by one (several times) and nothing makes the screen stay on but removing the Logic Board makes the blue LED stop blinking. Adding to the frustration the screen displays static for a few seconds before powering off.

Assuming a continuity test on the buffer boards (see http://blog.coppelltvrepair.com/2010...er-boards.html) works with this model the buffers are good.

Part of me wishes this was an easy fix while the rest of me is looking forward fiendishly to learning how to use an oscilloscope to test components and PCBs in general.

I feel like Little Orphan Annie..."Tomorrow" I should have the oscilloscope.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

A nice tutorial: https://www.youtube.com/watch?v=SxZWcku_Sw0

Nice indeed. Where did he get that font?

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Got the oscilloscope. The guy didn't know anything about it and I couldn't find the Cal output. We played around with the dials while the probe was in Ch1 and were able to alter the signal on the monitor but that's it. I couldn't get a square wave and I'm only guessing that a square wave is a right angle.

I'm a little scared but it IS Halloween. I bought the scope anyway and I'm hoping it works. I haven't been able to find a service manual for it. I'm going to do some more research into how to use it.

Cheers

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Your CAL output is the PROBE ADJUST point.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Your CAL output is the PROBE ADJUST point.

OK. I had to play around a bit but I got a square wave |_| after touching the probe to the ADJ point

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Should start a new thread and post the link in this one? I feel like I'm about the broaden the "scope" and it may be more beneficial to others if the title of the thread mentioned "oscilloscope". IDK.

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

That would be good.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

I opened a new thread at https://www.badcaps.net/forum/showth...990#post386990 to try and solicit assistance in using an oscilloscope to troubleshoot my Hitachi P50S602 plasma. I will post back here if and when I discover the faulty component/board.