How to Fix Tuner Fault in LG 49SK7900PVB LED TV | No Signal & Channel Issue Repair Guide
I have an LG-49SK7900 tuner repair in my workshop. Cable channels were not coming on this TV. I tried tuning it. but no channels were received. At first glance, I thought that the tuner was faulty. The customer said that we were watching a program on the TV when suddenly the screen went black. The menu kept appearing on the screen. They even reset the TV. But the channel did not come. I told the respected customer to leave it with me for two days; I will diagnose the fault and tell you how much it will cost to repair it. They agreed and left the TV.
Tuner Fault diagnosis
I opened the TV in the workshop lab and physically inspected its tuner area to see if there was anything unusual. I removed the cap on top of the tuner. It had two ICs installed in it, and physically it was in perfect condition. Now I checked the voltages of the tuner section; they were also there. I checked the clock data; its 100-ohm resistors were perfect, and the connection to the system IC was perfect. I checked the IF output of the tuner, up to the system IC; it was also fine. Now I decided to try disconnecting the tuner from the main board.
LG Tuner Ebl61841001
I removed the tuner from the main board with extreme care. To remove it from the circuit board, I used a sucker tool to desolder its soldering. Since this is a complete package tuner, it not only receives analog channels but also digital channels. It has a lot of pin connections, so the process of separating it from the circuit board requires extreme caution. Well, I took it out and removed its back cover. It has two pin connections, one for a regular cable and one for a digital channel. The center point of its antenna pin seemed to have a spark. I cleaned it with thinner. and it became clear that the spark had damaged a ceramic capacitor.
LG tuner repair
I washed the spark section thoroughly, and the center line of the cable pin, which was completely burned due to the spark, was also damaged by a ceramic capacitor that passes the signal from here. I took the capacitor from another tuner and very carefully inserted it into the circuit. This LG TV must have actually been exposed to high voltage from the cable, which caused this malfunction. Anyway, I replaced the faulty part and replaced the tuner with its backside cover and top cover. I soldered the tuner to the main board, made all the connections to the main board, and turned on the TV switch. I opened the TV’s main menu and turned it on for tuning. While tuning, I realized that the set had started receiving channels.
- Fault No Signal and Channel Issue.
- Faulty Part Tuner.
- Tuner Repair.
- Replaced the ceramic capacitor inside the tuner.
- Replacement ceramic capacitor my set started working perfectly all channel receive.
Conclusion
In this article, we referred to an LG model television that was not receiving channels because its tuner was faulty and its tuner was not working properly. This fault is caused by a high voltage spike from the cable, which causes the tuner to burn. In this case, the problem was limited to a ceramic capacitor, but sometimes the damage can be quite large. Branded LED TV Used tuners have less loss because they are very well designed. If this same cable spike voltage were to hit a low-quality tuner, the tuner itself could burn out and also damage the system IC. Well, in this case, we repaired the tuner by replacing a ceramic capacitor. Up If your LG is also not receiving channels, this article may be helpful for you. Note: Install a cable protector on your LED TV. This protects your TV from high voltage spikes.
FAQs – LG Tuner Fault No Signal Repair
Q1: What causes No Signal issues in LG LED TV?
No Signal issues in LG LED TVs are commonly caused by a damaged tuner, often due to a high voltage spike. Depending on the severity of the damage, the tuner may be repairable or might need to be replaced entirely.
Q2: Why are the channel signals weak in LG LED TV?
Weak channel reception is also typically related to a tuner fault. The tuner IC might be receiving a weak signal, could be internally damaged, or the AGC (Auto Gain Control) circuit may be malfunctioning—resulting in poor signal amplification and degraded picture or channel quality.
Shaukat Ali
Shaukat Ali is a professional Sony LED TV repair technician with over 30 years of experience. He specializes in diagnosing and fixing complex display and board-level faults. Based in Lahore, he shares real-world repair cases to help both customers and fellow technicians.