Re: Post The Led Backlights Your Fixing Here.
Working on fixing a Vizio e420i-a0. Found several bad LED's and have already replaced them. These LED strip's are attached with what looks like double sided tape, which was destroyed when removing the light strip's. My question is, how hot do these LED light strips get after they've been on for a few hour's? I have some Aluminum ducting tape that I thought I could use, though i'm not sure if the heat from the LED's would melt the adhesive on the tape. From what I've found, the Aluminum ducting tape has a max temp of 250°F.
hellride
Member
Last Activity: 07-29-2017, 05:23 AM
Joined: 10-02-2013
Location: georgia
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Re: VIZIO M3D550SR sound and faint picture
Yeah, sorry about that.
My dad works for Directv, so he got the TV from the original owner and gave it to me. My dad went to the owner's house for a DVR upgrade, not a service call, so the lightning strike must have happened month's ago. Original owner didn't tell him anything about it, just to take it or it was going in the trash.
Didn't get the original owner's phone number till yesterday. Called him and he told me what had happened....Leave a comment:
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Re: VIZIO M3D550SR sound and faint picture
I tried a replacement LED driver board in it a few days ago, it wasn't the problem. The board was relatively cheap, so it wasn't a huge gamble.
After my previous post, I started checking all the HDMI port's on the TV. HDMI 1 and 2 get no signal at all, 3 and 4 work though. Talking to the previous owner, he said Directv had to come out and replace all his HD boxes because of a close call with a lightning strike. Having fixed a few TV's under similar circumstances before, the power surge likely traveled from the HD box through...Leave a comment:
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Re: VIZIO M3D550SR sound and faint picture
Well, just figured I'd report back and say I got the TV working!!
budm, thinking about what you said about the DIM voltage not being present, I tested it again using a lower setting on my DMM. It was showing voltage, only 0.19v though which still seemed way to low to me. So just for the sake of experimenting, I disconnected the DIM line going to the LED driver, plugged the TV in, pressed the power button, and it powered right up!!
Question is though, would this be a power supply or mainboard problem? And would...Leave a comment:
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Re: VIZIO M3D550SR sound and faint picture
So since this TV is just sitting around, I figured I'd experiment on it. The worst I could do was damage something in a TV that is pretty useless in it's current state.
So I wanted to see if I could get any response from the LEDs with the mainboard disconnected. So, I disconnected the mainboard and applied 5v to the PS-ON pin. The original voltage reading I got from this pin was 1.7v, so when I applied the 5v to it, i fully expected something to pop. To my surprise, it didn't pop.
I than applied 3v to the...Last edited by hellride; 03-28-2015, 02:18 AM.Leave a comment:
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Re: VIZIO M3D550SR sound and faint picture
That's what I figured. The TV was free so, it was worth a shot at trying to get it going. I appreciate all the help we've given me.Leave a comment:
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Re: VIZIO M3D550SR sound and faint picture
I was afraid of that. I suspected it could possibly be bad LED's, so I started stripping the TV down to the panel earlier to see if I could find any damaged one's. I got as far as pulling the metal frame around the panel off and lost my nerve to go any further after that.
Having stripped down lcd's on laptop's and small monitor's in the past, it's a pain to keep dust and finger prints out of the many layer's of the lcd. That and this lcd panel being pretty fragile, I didn't want to go any further.
Looking...Leave a comment:
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Re: VIZIO M3D550SR sound and faint picture
Tested both filter caps when turning the TV on. The left filter cap jumped up to 71.2v and slowly dropped down to 50.2v. The right cap jumped to 71.1v and slowly dropped down to 50.1v
Disconnected the connector's and tested again. Left cap jumped to 74.2v and slowly dropped to 50.2v. Right cap jumped to 74.1v and slowly dropped to 50.1v.Last edited by hellride; 03-15-2015, 07:21 PM.Leave a comment:
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Re: VIZIO M3D550SR sound and faint picture
After taking the shield off, I did find label's for the left and right connectors, which is shown in one picture. Left filter cap read 50.2v and the right read 50.1v....Leave a comment:
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Re: VIZIO M3D550SR sound and faint picture
Disconnected the ribbon cable going from the T-CON to the LED driver board, no change. Still get sound and with a flashlight held to the screen, you can see a picture, but the backlight isn't turning on.
I want to say the LED driver board is the problem, but testing the connector's at the top of the LED board, it is showing voltage going out to the LED.'s Though I'm unsure of what the correct voltage for those connectors is suppose to be. Here is the voltage readings I got out of the led board top connectors:
...Leave a comment:
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Re: VIZIO M3D550SR sound and faint picture
Couldn't find the edit button in my original post to post these. Battery died on my camera, so I wasn't able to get a picture of the LED driver board and the T-CON board, I'll post those when the camera charges. Sorry if the quality isn't great, not the best with camera's. If better pictures or something specific is needed, I'll try to get it.
Also want to correct a mistake on my original post. The DIM going to the mainboard is reading 5.1v. I get no voltage on the DIM going from the power supply to the led driver....Leave a comment:
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VIZIO M3D550SR sound and faint picture
Recently picked up this Vizio M3D550SR for free and figured I'd have a go at trying to get it working. The problem is, this TV has me a little confused. The Vizio light on the front is on, the TV output's sound and when a flashlight is held to the screen, you can see that the lcd is working, but for some reason the LED's aren't turning on.
So I starting checking voltage's going from the power supply to the LED driver board, these are the voltages I got:
24v-23.6v
24v-23.6v
24v-23.6v
24v-23.6v
24v-23.6v
GND
GND
GND...Last edited by hellride; 03-15-2015, 12:00 AM. -
Re: New Members - please post your introductions here
Since it's required to post first before starting a new thread, just figured I'd say Hello!Leave a comment:
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