How to make a USB Wi-Fi adapter from a broken Smart TV.md

How to make a USB Wi-Fi adapter from a broken Smart TV

This article could easily be titled How I fixed a 50 inch Vizio TV for $26 and made a Wi-Fi adapter with the leftover parts. Here is a photo of the finished adapter.

A few days ago, I was on my way home and noticed that someone threw out a 50 inch LCD TV. It was in mint condition---not a single scratch, and it didn't even have dust on it. So I took it home to see if I could fix it. It turns out that the TV was stuck on the Vizio logo. This was probably because of a corrupt eeprom chip. The chip was $15 and the motherboard was only $26! So I replaced the old motherboard and the TV worked perfectly.

The TV is from 2013, the built-in apps we're outdated, and I was going to use a modern FireStick anyway, so I had no use for the built-in Wi-Fi. I looked on the motherboard and noticed a little white sticker that had a MAC address and an FCC ID (NKR-DNURW5370). That's the Wi-Fi module! It also had a model number (DNUR-W70B) as shown in the photo below.

It looked like it was easy to remove, and it had a pigtail connected to an antenna on the left side. It also had five pins on the right side. I Googled the FCC ID / model number and found that it had a non-standard USB connection. So I broke out my $2 multimeter and tested each pin for continuity against one of the screws on the motherboard. I did this while the TV was on. This revealed that the 1st pin starting from the left was grounded (black). Then I tested each pin for voltage and found that the 4th pin had +5 volts (red). This meant that pins 2 and 3 were for data (white and green). I believe the 5th pin was also grounded. The photo below shows the connection.

So now it was a simple matter of shutting off the TV, and carefully removing the USB Wi-Fi adapter card. I checked if the TV would boot up properly without this card installed, and thankfully it did. I was in the home stretch now.

Among my spare parts, I found a USB cable from an old webcam that had a plug on one end that happened to fit perfectly onto the five pins. You'll notice that I plugged it with one pin dangling so that the 5 volts would be on the correct wire. I found a pigtail connector from a broken PCI Express to Mini PCI Express Adapter Card. And I also had an antenna from an old broken modem.

With all the hardware parts in place all I needed was a nice little case. I just so happened to have a little plastic box that the card would fit in perfectly. I think this was some sort of jewelry case for a bracelet or something like that. I drilled a hole on the top for the antenna. I used a razor blade to carefully cut a notch on the side for the cable to fit in. I also made sure that the case would snap shut. Here's a photo with the case open.

And now for the Moment of Truth. I plugged in the USB Wi-Fi adapter to a PC that was running Linux. It was immediately detected and since the drivers were already pre-installed, I was able to connect to a Wi-Fi network. Running lsusb shows the following output:

Bus 001 Device 002: ID 058f:6377 Alcor Micro Corp. AU6375 4-LUN card reader
Bus 001 Device 005: ID 148f:5370 Ralink Technology, Corp. RT5370 Wireless Adapter
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

I also ran dmesg and it also shows proper detection:

[ 2297.768058] usb 1-5: new high-speed USB device number 5 using ehci-pci
[ 2297.941643] usb 1-5: New USB device found, idVendor=148f, idProduct=5370
[ 2297.941650] usb 1-5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 2297.941654] usb 1-5: Product: 802.11 n WLAN
[ 2297.941658] usb 1-5: Manufacturer: Ralink
[ 2297.941660] usb 1-5: SerialNumber: 1.0
[ 2298.076058] usb 1-5: reset high-speed USB device number 5 using ehci-pci
[ 2298.242622] ieee80211 phy1: rt2x00_set_rt: Info - RT chipset 5390, rev 0502 detected
[ 2298.271120] ieee80211 phy1: rt2x00_set_rf: Info - RF chipset 5370 detected
[ 2298.271752] ieee80211 phy1: Selected rate control algorithm 'minstrel_ht'
[ 2299.332318] ieee80211 phy1: rt2x00lib_request_firmware: Info - Loading firmware file 'rt2870.bin'
[ 2299.332404] ieee80211 phy1: rt2x00lib_request_firmware: Info - Firmware detected - version: 0.29

Please note that the number 5370 in the above two commands matches the one in the FCC ID.

So there you have it. That's how I made a USB Wi-Fi adapter. I was lucky that I found a particular TV with a particular Wi-Fi module that made it just too easy, and required no technical skill.

And, oh yeah, I have a 50 inch TV as well.

Nice!

I checked if the TV would boot up properly without this card installed, and thankfully it did. I was in the home stretch now.

Does it spin, then timeout, or does it never try to find the wifi?

Thanks. It simply never tries to find the wifi. I do use the TV with a FireStick though.

Wow
I literally just found a Vizio TV last week sitting in my alley so I grabbed it.
I plugged it in and it wasn't powering up
So I took it apart to see if I could figure out the problem.. a wire had a bad connection.
And it powered right up.
I also removed the wifi module in hopes to use it to make a wifi adapter with it.

I just got into electronics and don't know much yet.

Thanks for the post.
It was spot on with what I was looking for.

In my Vizio E50x-E1, as delivered from the factory, the TV wants to connect to WiFi. I never gave it a WiFi password, so when I power on, even though the last input is active (a computer on HDMI input), it often "decides" to poke at the WiFi and spin while I wait. Nothing I tried gets past this annoyance.

I took off the back of the TV, disconnected the cable that connects the WiFi board. The TV still booted, but no change in wasted time; still spun while it looked for a response from the WiFi, even though there wasn't even a cable connecting it. Oh well, I guess I'll need to get used to this.

Nice!

I checked if the TV would boot up properly without this card installed, and thankfully it did. I was in the home stretch now.

Does it spin, then timeout, or does it never try to find the wifi?