Intro: $5 TV Fix
One fine day, my TV stopped powering on. It was a shame since it wasn't brand new, but it still seemed to have plenty of life in it up to that point. After a little bit of searching around, I found this model had a common issue. A few TV repair shops quoted $200 or more for the work (and even they weren't sure they could fix it in the quoted time) and that seemed a bit much considering that was close to the cost of replacing the unit itself, so I wanted to see if I could fix it and keep it out of the junkyard.
Spoiler alert: yes. Yes I could.
As a note, I'll detail a bit of how I fixed it, but this is more of an Instructable about "good stubbornness" and finding the right resources if you're not already skilled in these types of things. If you are, you already know more than me. I tinker, but I'm not an engineer and never had training on this type of work. What I hope to impart is:
1) If you want to keep something out of a trash heap, especially a big, mostly-functional electronic box, be a bit stubborn. The internet is wonderful and many people have debugged things in popular models of consumer electronics and shared it in amazing detail (like on Instructables). Sometimes you might have to keep digging, but it's a fun puzzle.
2) If you don't have the skills to solve a certain problem yet, broken things are kinda great. First, they're already broken so it's not the same risks as taking apart a functional TV or other object, which can free you up to learn without as much pressure. Second, if you used it as a functioning object first, you know what state you're getting back to! Which is great and more bounded than creating something from scratch.
So with that, let's dive into the saga of my Sharp LCD Television Model LC32D43U...
Step 1: Debug, Isolate, & Find Resources
I found this short video that pertains to our model and several others have failed this same way. So I figured it was worth a shot!
(I originally used some specs from a link I can no longer open, but linking here anyway in case it works for someone else or at a later time.)
So what's up?
This model has a diode that often fails in the power supply, meaning the rest of the TV is probably in perfect working order. I unscrewed the back of my set with the TV gently laid down on a blanket and identified the area where I was looking for evidence of the broken parts. I could see enough to feel convinced my set suffered the same fate as all the other reports and bought the necessary parts.
Tip: I recommend taking photos at this point of your set while it's still mostly put together so you can refer to them when it comes time to put it back together. Also, put all the nuts&bolts in a bits box! You'll be thankful later.
I did the work by removing the power supply from the set (which was necessary anyway) but it also allowed me to travel lighter as I wasn't doing the soldering in my apartment. I put the broken part in a tupperware container and trekked across the city.
Tip: Given that this was my first time working through an issue like this, I bought extras. Each single part was inexpensive and I figured if I burned one while soldering, I'd rather have another handy.
If you have the same problem, here's the links for the two parts I bought to fix the set.
Safety tip: I consulted a friend with training in this space before beginning and wanted to share the same wisdom with this audience:
Before you begin, how much do you know about safety around electronics? Can you identify a capacitors? (Hint: They're the cylinders with the K or peace-sign looking indentation in top). Capacitors store energy, basically as a filter/buffer so that the not-so-clean power coming into your device from the wall can be smoothed out to make nice, clean, reliable amounts of power for the device to consume.
This is important for 2 reasons:
a) Capacitors can store a ton of energy. In old CRT TVs this was easily enough to kill you. With LCDs, it's still enough to give you a very solid jolt. At a minimum, leave the device unplugged for as long as possible before beginning work. Ideally you'll discharge them. Good info on how to do that is here: http://www.repairfaq.org/sam/captest.htm
b) Older capacitors are known to fail. Various batches from about 2002 until about 2010 had problems. It was a bigger problem with desktop computers, but not unique to computers. See https://en.wikipedia.org/wiki/Capacitor_plague . If the caps on your board look like that, they might need to be replaced.
Fixing stuff is great! Always double check that you're being safe!
Step 2: Remove the Broken Parts
Once you're sure about safety, the actual replacement isn't hard. Everything is through-hole mounted and soldered in place. Removal is just a matter of desoldering, removing the old component, cleaning up any leftover solder, installing the new component, and then re-soldering the new component.
Can you see the burnt areas around the existing diode? This is how I knew the diode was the culprit of my power issues.
I removed them using a soldering iron and a 'solder sucker' to remove enough material that I could free the parts I needed to replace. (Note: the photo of the tools is from the link here and not mine - too tricky to take photos of this part yourself!)
Step 3: Add in the New Parts
Your new solder doesn't have to be pretty, but you don't want it so ugly that it touches any of the adjacent components or board traces that the original factory solder didn't touch.
Check out the board with the parts removed and slotted in.
Step 4: Kick Back and Watch TV!
In my case, this was the exact cause of the issue and I was able to fix it the first time through. Putting the set back together was straightforward - there's only one way for most things to fit - and this is where you'll be thankful to have those original images to refer to if you aren't sure.
Fun aside: I was fixing this in a community workspace (more brains to pick if I hit a snag!) and a group from Shanghai came through our San Francisco space. They asked what I was up to and really appreciated my drive to fix instead of replace and one person asked for a photo with me, so I asked for one in return!
I hope your TV doesn't break, but I hope if it does you also wonder if it's something you could fix yourself. In my case, I didn't need the fancy electronics setup you see here - just a soldering iron and the solder sucker (and some good ventilation!) But it's not just TVs - lots of things can have longer lives if we apply some good stubbornness and see what other knowledgable humans have shared so we can accelerate our own learning.
Thanks to all who helped me stretch my skillset comfort zone and complete this project successfully!