Techie117
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Mar 30, 2012, 5:15 AM
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42" Vizio E421VO does not power on- no lights. Technical.
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Hello tv-forums I'm a fan of Ron.M's work here! I searched for "E421V" but there appears to be no threads for this relatively new TV. I figured I'd go ahead and start a thread about mine in hopes that it will help myself and others fix their broken Vizio. I'd like for this thread to get technical but understand I may be shooting in the dark. Warranty status: It's not covered under warranty because I lost the receipt and Walmart failed to find any receipts of our purchase from last December because we paid cash :o Model #: E421VO PSU part #: 3PCGC10017A-R Main board part #: 0171-2271-3276 The TV will not power on. No lights. Not even the orange light will power on. I have tried multiple power cords on multiple outlets. The power supply board has been replaced with a tested working one and nothing changed. I am pretty confident it is the main board that is bad but they seem to be sold out everywhere. I would like to fix the main board myself anyway, as I have experience soldering and am hoping it's something as simple as one of the tiny 3-pronged voltage regulators that is bad. The t-conn board appears to be built-in to the main board but I'm no expert. I have tried Vizio's suggestion of unplugging the power cord, holding down the power button for 45 seconds then releasing the power button and plugging the power cord back in to try again. Of course it did not work :D I have carefully examined the entire board (top and bottom). No capacitors are bulging or appear to be bad and there are no obvious burn marks of any kind. Everything appears like new except perhaps this tiny, tiny, flat, black, ~5mm by 5mm (1/5" by 1/5") chip that has 7 legs on each side (14 total), which appears to have a tiny amount of cloudy white stuff on top of it. It does not rub off with a fingernail. I don't think it is the problem but who knows. Please SEE PIC 1 I have tested the voltages the power supply board is supplying the main board with the cable both, plugged in and not plugged in to the main board, with the same results. The 3 pins that should read 5.2v are reading 5.25v so good to go there. The 3 pins that should read 12v are reading 0.00v (Even after pressing the power button). The VBR_B, STATUS, and both ON/OFF pins read 0.00v (Even after pressing the power button). The speaker terminals and 3 pins on the bottom of the board going to the front LED also read 0.00v. In fact, I'm not reading any voltage anywhere on the main board I've tested EXCEPT on what appears to be a tiny rectangular fuse-like thingy that says "IE3A" which is located right next to where the power comes into the main board. The other tiny rectangular fuse-like thingy, which is next to the other one, says "IE5A" and reads 0.00 volts. Perhaps this is the cause. If so, does anyone know the correct terms to google? I have tried '"ie5a" lcd' with no success. Do you know what this little guy is called? SEE PIC 2 From what I understand (Though I could be wrong), the reason the power supply board (PSU) is not sending 12 volts through the cables is because it is not receiving the "turn on" signal from the main board. Here are some photos that will make it much easier to picture: PIC 1 Cloudy white stuff on top of the tiny tiny chip PIC 2 Voltage readings Thoughts? Thanks in advance for your help :-)
(This post was edited by Techie117 on Mar 30, 2012, 11:15 AM)
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