Vizio Main Board

DIY: Replacing the Main Board on a Vizio P50HD TV to Fix Broken HDMI Input 1


Vizio Main BoardWhen the HDMI port stopped working (about a year out of warranty, of course) on the Vizio P50HD 50″ plasma TV in the living room at our Utah house, I thought “huh — that’s weird,” then promptly unplugged the HDMI cable from “HDMI In 1” on the TV, plugged it into “HDMI In 2,” and was happy to see it worked.

It continued working fine for another year or so, but then that HDMI port stopped working, too. So I switched over to the component video and RCA audio cables (which thankfully, I’d already run behind the wall) and everything was fine again.

But when I wanted to add a Sony Blu-ray and streaming network video player to my setup (for watching Netflix and Amazon Video), I was bummed to discover that those devices require an HDMI input… and both those inputs on my TV were dead.

I’d owned this 50″ plasma TV for 6 years, and although I would have hoped to get more life out of it than that, I’m always looking for an excuse to buy new A/V equipment, so off to Costco I went to shop for a replacement. A new 50″ Vizio LED replacement was $639.99 — which is expensive enough that it made me think twice about tossing out my current model, especially since the one back home on my wall was only “sick” and not “dead.”

When I got home, I called a local TV repairman, with good online reviews, and described the problem to him. He said this problem was very common on TVs in this area, because power surges and lightening storms can adversely affect the HDMI circuitry, which would explain why they stopped working one after the other, and the other inputs still work. He said that he could diagnose the problem for $50, and then probably replace the main board (where all the inputs are connected) for around $250. That would be less than half the cost of a new TV, so I thanked him and told him I’d think about it.

And think about it I did… and then decided to call Vizio’s toll-free number to see if they would sell me the input board directly. They informed me that the board I’d need was part number 3850-0022-0150, and referred me to their VizParts.com website to purchase it online for $158.75. That means I could save almost $150 by simply ordering the part from Vizio and replacing it myself.

But I hate paying retail for anything, including replacement parts, so I searched for the part number on eBay and came across a good selection of used, refurbished, and/or re-certified main boards for my TV. I found a seller with good feedback and used Buy It Now to pick one up for $33 (with free shipping). I had it delivered to the Seattle house, since I was headed back home before it would arrive. This is the actual replacement part I purchased:

Vizio P50HD main board from eBay

Vizio P50HD main board from eBay

On my next trip down to the Utah house, I asked a couple of college kids from back home to help me pull the TV off the wall (it’s very heavy), and then I simply followed the instructions from a YouTube video of how to remove the back cover and pull the board (technically, the video showed how to pull the control board, rather than the main board, but it was helpful in knowing what the inside looked like and how to remove the cover). If you’ve ever replaced a motherboard in a computer, this is exactly the same process: remove the cover, unplug all the cables, unscrew the old board, pop in the new board, put in the screws, plug everything back in, put the cover back on. Everything went smoothly, so I grabbed a brand new HDMI cable (the cable in the wall wasn’t long enough without re-hanging the TV), confidently plugged one end to my new Sony Blu-ray player and the other into HDMI In 1 on the TV, then turned everything on. I screamed a joyful “YES!” when the Sony logo appeared on the screen, but my joy turned to panic when the logo disappeared, and I couldn’t get it to return. I tried the 2nd HDMI port, with no luck. I tried turning the TV on and off, and the Blu-ray player on and off, in various orders, with no luck. I was certain the brand new cable must be fine, so I figured that maybe something “upstream” of the main board (such as the power or control board) was malfunctioning in the TV, which had fried this newly installed board just as it had the original one. I had the kids help me load the TV into my SUV, and dejectedly decided I’d drop the $300 to get the thing repaired.

Later that day, I dropped the TV off at the repair shop, told the owner that I’d already replaced the main board and got a flicker of video image before it went dead, and paid the $50 diagnostic fee. He said he’d try to have it done within a few days. I went back home to stare at the lonely cables hanging down my wall where my beloved TV used to sit.

The next day (which is today), I decided to grab the 42″ TV from my bedroom and temporarily move it into the living room so I could at least watch the stuff recorded on my living room DVR. I plugged in the power, connected the new HDMI cable from the DVR to the TV, and turned everything on. Nothing. Blank screen. What the….?

Then I realized I’d made a rookie mistake. I’d assumed that because the cable was new, that it must be functional. I went back into the bedroom and grabbed a different HDMI cable (the one that was connected the Blu-ray player in the bedroom) and used it to connect everything back up in the living room. Everything worked fine. I switched between the two cables two more times to verify: I had a bad cable! In fact, I had probably damaged it myself by by over-stretching it while trying to test the big TV before remounting it on the wall, which is why I got a blip of video signal before things went dead.

I immediately called the TV repair shop and told the owner that I think the TV might actually be OK, and that I probably was using a faulty HDMI cable. He said he’d already started diagnosing, that he’d gone through everything in the circuitry, and everything seemed to be working fine. I told him I’d be there in 20 minutes to pick it back up.

I brought the TV back home, got one of the college kids back over to help me re-mount it on the wall (I bought him lunch at In and Out as a token of thanks), plugged in all the connections, and turned it on. HDMI was working! Turns out my repair had worked fine — and a faulty test cable had cost me an extra $50 in TV diagnosis. But even with the cost of the part and the unnecessary diagnosis, I was out $83 instead of $150 or $300.

So the moral of this blog post is that by using online sources like eBay and YouTube (or Amazon, or specialty parts suppliers), you can generally find parts way cheaper than most retail outlets, and repair many things yourself way cheaper than hiring a professional. Don’t be afraid to try, especially if the next best option is simply buying a replacement. If the repair doesn’t work, you may be able to return the part to the seller, or if you buy the part with a credit card that has some sort of purchase protection program, the credit card company may simply reimburse you the cost of the part if the merchant won’t take it back (Amex has done that for me twice).

So whether it’s a TV, or a hot water heater, or a Sea Doo, take a stab at fixing it yourself. Best case, you’ll save yourself some money. Worst case, you’ll learn something, even in failure.