Samsung UA40EH5000R Dead Issue Repair | After Voltage Surge
Introduce
Samsung UA40EH5000R Dead Issue Repair This LED TV was brought to my workshop for repair by a customer. The customer said that this TV was working perfectly when suddenly a blast sound was heard from inside it and it turned off. We failed because suddenly the voltage increased; that’s why it turned off. I asked the customer if you didn’t install any protection device with it. His answer was no. I think its power supply board (SMPS) was damaged. I took the time to work and told him that I will let you know after diagnosing it, and then with your permission we will fix it.
Diagnosing the Power Supply Board (SMPS)
I opened this Samsung LED TV in my workshop lab. Since it was an old set, it had a lot of dust in it. I cleaned it and took apart the power board. First I checked its fuse, and it was an open circuit. This is a common thing. Whenever there is a severe surge in the SMPS board, the fuse’s job is to open V as a safety feature. After that, I checked its bridge rectifier with a multimeter, and it was fine. Next, it was the main capacitor that exploded. Its value was 100 UF, 450 volts. Its chassis number was CP801S. There was a fuse and ZNR on the main AC. V was also shorted. It was the ZNR that caused no further damage to the power supply. If it had not been shorted, the MOSFET and IC would have been damaged.
- ✅ Samsung UA40EH5000R Power Supply Fault – Key Points
- Fuse found open due to high voltage surge
- Bridge rectifier tested and found OK
- Main capacitor (100uF, 450V) was exploded
- Capacitor part number: CP801S
- ZNR was shorted, protected other components
- No damage found to MOSFET or PWM IC due to ZNR protection
Repair power supply UA40EH5000R
Now let’s come to the power supply repair. The main fuse of this power supply was burnt, even its stand was burnt, I replaced it. After that, I replaced its ZNR. The main capacitor was blown. I replaced it. And once again, I checked this power supply with a multimeter to further assure that there was no short circuit. I checked its MOSFET. It was fine. There was no short circuit there. And its ICPMW circuit was also fine. There was no short circuit there. Everything was fine. So, I replaced the faulty components. Then I connected the supply to the main AC and turned it on. I checked the voltage of the power supply and these voltages started coming up.
Prevention Tips (Avoid Future Damage)
As a safety measure, plug your LED TV in during thunderstorms and unplug it when you see that the light is flickering. Disconnect your television from the main AC plug. Be sure to use a voltage-protected device with a good quality delay timer so that it can protect your LED TV. Run it on a UPS, but the UPS should be good. It should be a sine wave UPS, and do not run it on a weak UPS that fluctuates. Do not run your LED TV on it. You can run it on a solar system because it is providing pure solar AC. You have no problem with that. You can run it. The customer cannot take more precautions, but you must do what is in your power to keep your thing safe. The rest is electronics; anything can happen to it.
Estimated Repair Costs
If you get the same power supply work done by a good professional technician, it can cost you around $20.
Conclusion
I had this Samsung LCD TV for repair. It had a power supply fault, and I repaired its power supply. Some parts were damaged in it. When I replaced them, the set was fine. But the lesson here is that you must install a protected device with your LED TV or LCD TV or install it yourself. It should be of good quality. Now it keeps your LED TV safe, and you can avoid damage with it. We have also included pictures in this article, and we have put protection in this article completely, and the common consumer can also benefit from it. You can make your work easier by looking at it. If you have any questions about this, you can ask in the comment box. I will definitely answer.
Q1: If the power board is damaged, is it feasible to repair it, or should it be replaced?
A1: It depends on how much damage has been done to the power board, but in my opinion, if you can repair it, then you should repair it.
A2: But in these cases of electrical surges, sometimes the supply gets completely burnt out and is no longer repairable, so it is forced to replace it.
If you want to read the article on how to fix Sony KLV-32R302F 2 Blink Error, click here.
Shaukat Ali
Shaukat Ali is a Master Craftsman and Technical Researcher in the field of Sony LED TV repair, with over 30 years of professional experience. Known for his deep understanding of display and board-level faults, he combines hands-on skill with investigative precision to deliver long-lasting repair solutions. Based in Lahore, he has earned a reputation not only for accurate fault diagnostics but also for sharing real-world repair case studies. His mission is to educate both customers and fellow technicians through tested methods, avoiding guesswork and focusing on authentic results.
💬 For service-related queries, contact me directly on WhatsApp: