Re: Toshiba 50HP66 - never turns on, clicks off when relay does
After about two hours of usage, I may have two IPMs out--lower y-sus and upper z-sus. The other heat sinks were too warm to hold long but these two were only warm.
I've attached some photos of the screen if that helps. (I reset the picture quality with the OSD menu before I started.) The input is an OTA signal which looks fine on a plain 27" CRT. The resolution on this is dismal and color changes are sluggish. If the background changes from black to blue, it takes time for the black to go away....
vince_o
Member
Last Activity: 05-16-2015, 07:01 PM
Joined: 01-26-2015
Location: WV
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Re: Toshiba 50HP66 - never turns on, clicks off when relay does
I also should point out that, before I made the TV vertical, screws from the y-sus and both upper/lower boards had been removed. I had removed the y-sus board (to check the underside) and had put it back in loosely because, if it was bad, I was going to take it out again.
When the screen had vertical bars, I had the grounding strap anchored and maybe one corner of the y-sus but the other screws were out. When I saw a working screen (snow at first, then Roku), it was only after I installed all screws....Leave a comment:
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Re: Toshiba 50HP66 - never turns on, clicks off when relay does
This is getting silly. Since the TV is laying facedown, I propped it up to see what the screen was doing. I powered it on, and instead of the vertical bars I saw yesterday, I saw an initialization message, snow, and black smears. I turned it off and then on again and the smears started going away. (It's in an unheated/chilly work area so I guess it needed to warm up a bit.)
I plugged in a Roku, changed to the proper input, and I saw the entire screen (the smears eventually went away). The resolution is...Leave a comment:
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Re: Toshiba 50HP66 - never turns on, clicks off when relay does
Oh boy, I get to hijack my own thread!
Put the original PSU back in last night. Powered it up, a few seconds later, I heard a loud "pop!". Oh well, at least it's acting differently.
Unplugged it, waited a minute, tried again--it stayed on! Pressed Power, the front LED turned green--and stayed on. Three LEDs and one under the LVDS cable lit up on the CTRL board. Great! It's acting "normal". Pressed Power several more times and the TV responded properly. (Guess the...Leave a comment:
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Re: Toshiba 50HP66 - never turns on, clicks off when relay does
Thanks for the clarification on how to test for shorts. My DMM's threshold is somewhere about 200 and, you're right, I was presuming a short just because of a beep.
When I retested the FETs last night, they seemed to be consistent. Either the two legs matched (lowest was mid-300's) or one was 3-400 and the other had much higher resistance. So, I guess I don't have FETs shorting like I thought.
The PO says he has the original power supply board so I may put that back in and see if it acts...Leave a comment:
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Re: Toshiba 50HP66 - never turns on, clicks off when relay does
Before I continue, let me verify my FET test method. I'm familiar with electrical work (low-voltage and 110 stuff) but circuit boards are not my cup of tea.
When you said test the FETs for shorts, I put one probe of my DMM on the frame and the other on one of the three legs of the FET. If I heard a tone, that's what I considered a short. If that's not right, let me know the proper way to test a FET.
My dilemma for continuing is the repair shop says they won't touch a board if they see evidence...Leave a comment:
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Re: Toshiba 50HP66 - never turns on, clicks off when relay does
Thanks for the suggestion. I checked everything that looked like a FET and found two on the z-sus board (D203, D204) and one on the y-sus (Q12). Although the next step is probably replacing these FETs (which I could do), it would be faster to send these boards to rehab in case there's something else to be fixed.
Thanks.Leave a comment:
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Re: Toshiba 50HP66 - never turns on, clicks off when relay does
Testing the fuse before assuming a result makes sense. Thanks for the clarification.
I had to decipher the second paragraph but, after I disconnected the LVDS cable, shorted pins 1-2 on P1, and applied power, the relay still trips in less than 3 seconds. Power (110V) still exists in places but DC voltage fades faster than I can find and measure it.
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Re: Toshiba 50HP66 - never turns on, clicks off when relay does
Fuses were checked several times and all found good.
I found Vs on the top side where the plug either comes in (z-sus) or goes out (y-sus) on that connector. I never figured there'd be another way. To test the underside, I'd have to remove the board and that seems add complexity to what should be a simple test. Then again, testing at the source does eliminate the link between the IPM and the connector...hmm.
Not to sound ignorant (too much) but what's the downside to testing at the connector?...Leave a comment:
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Re: Toshiba 50HP66 - never turns on, clicks off when relay does
Since the PSU was acting the same (relay shutting off the power downstream) whether or not anything was plugged into it, I was thinking it was the PSU. But, like I said, I'm learning.
Taking your suggestion, I tested continuity between Vs and chassis on both y-sus and z-sus boards but it didn't act as expected. To wit, if I test continuity between chassis and:
[LIST][*]chassis, my DMM beeps.[*]GND, my DMM beeps.[*]Vs, the DMM beeps briefly and then resistance goes back to 1.[*]Vs again, no continuity.[/LIST]...Leave a comment:
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Re: Toshiba 50HP66 - never turns on, clicks off when relay does
Thanks for the reply and directing me to the possible cause. If it is that simple (the AC detect pin is unstable) and it can be fixed with a bit of solder, I will be very impressed. I'll let you know what I find.
Thanks again.Leave a comment:
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Toshiba 50HP66 - never turns on, clicks off when relay does
My apologies for a newbie post but I'll endure some flak if I learn a bit about fixing TVs--well, okay, just this one TV. Someone gave me a 2006 Toshiba 50HP66 that "didn't work". Its PSU was replaced as the only repair attempt which didn't fix it. The owner got a new TV, I took this one.
I've read various posts (here and elsewhere) and, although I can fix various things, electronics at this level is sometimes a bit beyond my skill level. So, please bear with me as I stumble through the basics to get to where you can help (if possible).
[B]What I have - [/B]Toshiba... -
Re: New Members - please post your introductions here
Hello all. I have a computer background (just missed the punch cards by a year--whew!) and still know DOS commands like the back of my hand. Other than a bit of programming and network fun, I enjoy figuring out why things don't work--which is what led me to this forum.Leave a comment:
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