Yesterday at 7 PM, a customer brought in a repaired Hisense LCD TV model TLM32V78K. The issue was that the TV had trouble turning on. The power indicator light, which should be green, wasn’t lighting up. Sometimes it would start after several attempts, but once it turned on, everything worked normally and didn’t shut down again. The customer also mentioned their experience with Hisense’s after-sales service, saying it usually takes about a week to fix the board. I guessed maybe the cost of the replacement board was too high for them to accept. They mentioned that this problem has occurred before, and they were a bit hesitant about it. So they came to me, asking if I could fix it and how much it would cost. I told them the price was orange-black-brown, and finally we agreed on red-yellow-brown. After that, the customer left. At first, I thought it might be a faulty capacitor in the power supply. I opened the back cover and checked the capacitors, but they all looked fine. I decided to measure the voltage instead. The TV hadn’t been powered on yet. After connecting the power, I measured 5V at the 5VS pin, and the ON pin had around 3.5V. However, there was no 12V or 24V output. The voltage across the PFC filter capacitor was only 360V—shouldn’t it be 380V? Maybe it was due to a leakage in the sampling resistor? I didn’t think too much about it. I found that the sampling resistors were all soldered down. After removing the backing and re-soldering them, I tried powering it on again. A few minutes later, the backlight turned on! The PFC voltage was now measured at 380V. On the signal line, the image and sound were normal. After a few more on/off cycles, the TV started reliably every time. This morning, the customer came to pick up the TV. They were very excited to hear it was fixed. Thanks for your attention! Dropout Fuse Cutout and load drop fuse cutout are outdoor used high-voltage protective devices. They are connected with the main lines of the distribution transformer or the distribution wires to protect the transformer or wires from short circuit and overload, and on/off loading current. Dropout fuse cutout consists of insulating bracket and fuse tube. The static contacts are fixed on the two ends of bracket, while the moving contacts are fixed on the two ends of fuse tube. Fuse tube is composed of inner extinction tube and the outer epoxy glass tube. The load drop fuse cutout is added with elastic supporting contacts and arcing shield for switching on-off loading current. In normal operation, the fuse tube will form an enclosure via its tightened fuse link. The fuse will be melt off quickly and form an arc if there is any fault, the extinction tube is heated by the arc, exploding much gas to give high pressure into the tube and blow along with the tube, so the arc is quickly elongated and extinguished. When the fuse is cut off, moving contacts at the bottom turn down without tension; the locking frame will release the fuse, so the fuse drops to form obvious break. When it needs to put load on, start the contact with insulating cod, then the static and moving contacts are still keeping in touch, keep pulling the contacts till the supporting contacts apart. Then there is the arc among the supporting contacts, which is prolonged in the narrow space of arcing shield.At the same time, the arc extinguishing cover generates gas, and the arc is extinguished when the current exceeds zero. Porcelain Fuse Cutout,Drop Fuse Cutout,Fuse Link Cut Out,Cutout Fuse Holder Jilin Nengxing Electrical Equipment Co. Ltd. , https://www.nengxingelectric.com