Re: Vizio VT470M goes black after couple of minutes (no picture, yes sound)
By 'going black' do you mean the backlights turn off, or the picture goes away and the backlights are still on?
I'm not much on troubleshooting flat panel sets, but I've got the same model that will work for hours when I initially turn it on (after being off for about 30 minutes), but when I turn it off, then back on, I get no display except for backlights. I'm going to replace the capacitors on the main board (pretty much isolated it to that board, and there are a few in the power switching...
bbushong
Member
Last Activity: 12-01-2017, 02:27 AM
Joined: 10-10-2013
Location: Level Plains, AL
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Re: Verizon VT470M Service Manual
Well, since this main board has a multitude of Lelon, Capxon, and Elite caps installed, it didn't cost me anything, and I can always use the soldering practice, I've ordered Panasonic FC and FM caps to replace all 27 of the caps. Even if it doesn't fix it, I'll get some soldering experience, and it's only costing me about $22 and some time. Since it seems to me to be a power control problem, it may work. If it doesn't, it's not costing me much... worst case, I brick the thing and part out the pieces that work...Leave a comment:
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Re: Verizon VT470M Service Manual
I do find that I can pretty consistently get the set to start up and run if I unplug it and let it sit for about 30 minutes. I went into the factory settings (I think) by going to the menu, then pressing 1991 and enter. There is an option for 'EEPROM Init' but I'm not exactly sure what it does. I selected it a couple of times, and it just seemed to exit that menu, didn't reboot or anything that I could see.Leave a comment:
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Re: Verizon VT470M Service Manual
This is why I asked the first question about the complete service manual and how to check those specific components listed in the troubleshooting diagram. Just figured there was a reason they said to check those parts and replace if found bad. Maybe failure prone parts that can be replaced, rather than try to find a new board and toss this one. Only to find that the new one fails the same way...Leave a comment:
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Re: Verizon VT470M Service Manual
Yeah, that's where I'm leaning right now, but I don't see the main boards for sale anywhere... I'm willing to get one if it'll fix it, or I'm willing to attempt a fix on this one. Just don't want to get drawn into multiple expensive fix attempts... My time is experience, so I'm willing to spend that, but more than a couple hundred to fix a broken TV when I don't POSITIVELY know the problem... that's an expensive hobby...
If I can get it started again tonight, I'll see if I can do a factory reset... anybody know if it's possible to reinstall...Leave a comment:
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Re: Verizon VT470M Service Manual
Yep, the logo comes up for a few seconds, then works, when it works. If it doesn't work, no logo or anything, just blank screen with the backlights on.Leave a comment:
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Re: Verizon VT470M Service Manual
When it works: It works. Everything seems to work just fine, the first time I turn it on, after it's been sitting for half a day or so, unplugged. Vizio flash screen comes on, backlights come on and stay on, and it works. I don't know about the inputs, other than USB, as I don't have a signal in my shop (yet). I can play pictures and music from my USB drive, and get a great picture. Everything works except that power indicator that's so dim I can't see it.
Once it works, and I turn it off after oh, say two to three HOURS (or two to...Leave a comment:
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Re: Verizon VT470M Service Manual
When it works, the VIZIO flash comes on, and I get a blue screen with "HDMI 1" or "no input" or whatever. I can change the input on the screen, play music from my USB drive, etc. EVERYTHING works fine. While it was working, I tugged, pulled, tapped on wires and connectors while the music was playing, and I had the screen working fine (music playlist displayed). Yes, I checked the ribbon cables on the t-con board, wiggled the bottom two connectors on the t-con board. I guess I don't see why the t-con board would make the backlights...Leave a comment:
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Re: Verizon VT470M Service Manual
I took the cover off of the t-con board, and resecured the board with one screw. Nothing loose or burned under there... I turned the set on, and as expected, it worked. Wiggled, thumped, tapped, and tugged on every wire I could see, and not a glitch in the picture or sound. Turned it off, and turned it back on. Nothing but backlights, as before. Power seems good at all of the pins on the power supply and main board (each end of that main cable). When I turn it on, voltage at the ON/OFF pin goes to 5 volts, then when the backlights turn off, it drops...Leave a comment:
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Re: Verizon VT470M Service Manual
Okay, I'll give that a try, too. Thanks for all the suggestions.Leave a comment:
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Re: Verizon VT470M Service Manual
I've unplugged and plugged the two connectors to the t-con board previously, with no change. I actually unplugged and plugged them in with the TV on and not woorking, and the display didn't change or flash. I'll try it again tonight with the set working (if I can get it to work one time), and see if wiggling wires makes a difference.Leave a comment:
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Re: Verizon VT470M Service Manual
When it doesn't work, I just have the backlights with no picture. The backlights come on without fail every time I turn it on.
The first section in the troubleshooting procedures is for no power (no LED indicator), and I figure that's a good place to start, since the indicator is glowing so dimly.Leave a comment:
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Re: VIZIO VT470M Service Manual
Okay, here are some pictures of the boards. Not sure how detailed you want or need... Bits are free (Got a 64GB card in the camera), so I can take as many as will help out....Last edited by bbushong; 10-22-2013, 12:15 AM.Leave a comment:
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Re: Verizon VT470M Service Manual
Yeah, VIZIO. I was on a VERIZON phone, so I don't know if it autocorrected it, or if I messed it up. Probably the latter...
Okay, I've got a video of the TV starting up, working, great. The only thing that's strange with it WHEN IT WORKS is that the VISIO power indicator never turns amber. It's always dim white/gray when it's off, and when it turns on (every time, when it works or not), it just gets a little brighter, then dims down again where you can barely see it. When the set does NOT work, the power indicator does the same thing,...Leave a comment:
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Re: Verizon VT470M Service Manual
Really, I'm trying to get a feel if I should even think about attempting the repair. I'll post a full description of what is going on when I get home. Just too much of a pain to type on this phone. Similar to another problem I saw with one of these, for which I didn't see a solution posted.Leave a comment:
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Re: Verizon VT470M Service Manual
The only markings I see on those specific transistors are H1A and H2A.Leave a comment:
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Re: Verizon VT470M Service Manual
I guess, before diving too far into this, I should ask if you think it's even possible for me to test and/or replace the smaller components on this board. The specific ones in question are Q404, Q405, Q414, Q413, R4145, R4158, etc. I'm willing to try it, as the TV was free... But if it's going to be an exercise in futility, I may look for a replacement board if I can find one....Leave a comment:
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Re: Verizon VT470M Service Manual
Wow, messed up on the FIRST word of my first question... should be Vizio VT470M manual... guess that's what I get for using my phone for this...
I'll see if I can post some pics of the transistors I'm trying to check. They're surface mount, and teeny (for me, anyway). Not sure how they'll come out from my phone. I'm off in two hours, so it may have to wait until then.Leave a comment:
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Re: Verizon VT470M Service Manual
I've got a couple of digital volt meters and soldering irons. I have an o-scope that I'm itching to learn about; got it for another project that is on hold...Leave a comment:
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Verizon VT470M Service Manual
Howdy guys and gals! I have hapened across a VT470M that a neighbor was discarding, and figured I'd se if I could resurrect it. First thing I'd like, though, is a COMPLETE service manual for it. I've downloaded a few, and they're all missing pages 27 to 63, which I assume (from the table of contents) explains everything at the component level. For instance, the documents that I have say, at one point, something like check R4145, Q404, Q414, R4158, Q405, Q415. But there is nothing saying what they are, or HOW to check them. I found those items after searching a while, but I'm not sure what readings...
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