Recently, one of my long-time customers Jake, had sent in his “precious” 42-inch Toshiba plasma TV to me so I could take a look at it. I thought the TV looked brand new despite the fact that Jake bought it about 6 years ago, give or take. The guy really knows how to take care of his plasma TV – exterior wise that is.
So I conducted the customary initial inspection – just some basic stuff, and discovered that the TV couldn’t be powered up at all. I plugged in the power cable and the indicator light didn’t come on. Heck, not even a blink! Next, I thoroughly examined the power board looking for clues that could lead me to uncover the source of the problem.
The power board’s diodes were examined in a painstaking manner and lo and behold, I came across a couple of diodes that weren’t working anymore. They were severely shorted basically. Of course, I promptly removed the affected diodes and had them replaced with fresh ones. As a result, Jake’s Toshiba plasma TV was back in business, power wise that is. By this, I mean I was able to turn the power back on but the TV’s visual keeps shutting down.
Now, those with experience fixing faulty plasma television sets would know that when such issue arises, it definitely has something to do with the TV’s backlight. To solve this issue, I quickly put the inverter’s transformers through rigorous testing, and the result came out pretty good as I managed to trace the source of the issue. Apparently the test results indicated that they were two open high voltage transformers.
So out with the old transformers and in with the new, but guess what? The visual shutdown problem persisted…
Well, I’m persistent too!
There’s no way I’m going to let this problem get the better of me! And besides, I didn’t want to disappoint Jake. After all, he’s a long-time customer of mine and if I couldn’t solve this problem, he might just take his business elsewhere.
Anyway, I continued testing the TV’s components, wondering incessantly what the issue was when I finally stumbled upon it. Yes, I found out what the problem was…It was the mosfet ladies and gentlemen!
The funny thing is that when I tested the mosfet, it was running well and fine. However, when I allowed it to run at full voltage, it goes kaput. So I changed the mosfet as well.
All in all, I replaced a total of five components. The first were a couple of diodes, then a couple of high voltage transformers, and finally a mosfet. Problem solved! To make sure the TV would run perfectly, I turned it on and simply left it like that for approximately 6 hours. Nothing happened. Everything went well and Jake is super delighted that he got his Toshiba plasma TV back and running like normal.
