How to repair LCD TV Auto Change Channel Problem

How to repair LCD TV Auto Change Channel Problem

Model : Hisense TLM26V68 LCD TV

Chassis: MST721DU

Symptom: LCD TV with auto change channel problem



The complaint of this Television was TV channel will automatically change.During initial observation, the television sound and display were normal. The problem only occurs while watching television programs. First suspect was the remote control or the push button front panel controls.  Removed the remote control batteries the problem still remains.  Disconnected the CN8 connector (control panel pcb board of the tv) still with the same problem.


Have tried to replace the crystal of main chip, but the problem remain the same. After that, checked the supply voltage to main chip, 3.3V_MST line was getting 3.7V instead of 3.3 volt. So suspect the U2 3.3V SMD voltage regulator IC have problem. After replaced the U2 IC, the TV was back to normal!



Conclusion: Even this article a bit short, but it is helpful to us. We know why the lcd tv can be auto change channel during initial observation now. This method can apply to other tv like Plasma Tv too. So you can use this method to troubleshooting lcd or plasma tv mainboard and find out the culprit!




Related Post:
How to Repair LCD TV Auto Shutdown Randomly
How to Troubleshooting and Repairing LCD Monitor Randomly No Display and No Power Problem
How to Repair TV No Signal and AV have Display but No Sound Problem
The Method of Bypass LCD Inverter Protection
How to Repair LCD TV with Symptom No Display but Blue Screen and Vertical White Bars
Samsung Galaxy S4 GT-i9500 Smart Phone Repairing Information
How to Repair LCD TV No Display, No Backlight But Sound ok
How to Repair LCD TV Backlight Shurdown Randomly
This LCD TV Display Problem Can’t Be Repair!
After One Hour LCD TV Display Abnormal



To your success!

Kent
http://www.LCDRepairGuide.com
http://www.LCD-Television-Repair.com
http://www.Plasma-Television-Repair.com
http://www.Projection-Tv-Repair.com








V2- LED/LCD Screen Panel Repair Guide
















V4.0-LED & LCD TV Repair Tips ebook


V5.0- OLED/LED/LCD TV Repair Tips Ebook

Comments

Post a Comment

Popular posts from this blog

How to learn the SMD 6 Pins Power IC

Image
How to learn the SMD 6 Pins Power IC  Lots of the new LED TV and Monitor is using the SMD 6 pins Power Supply IC. This Power IC size is small like a normal SMD transistor! Sometime we can't find where this power IC location. But sure that for the season repairer they will knew that is power IC. But that's not mean they know what's their power IC part number! So It is important to learn this information when repair the latest LCD & LED TV or monitor. Below is the location of power IC (U7001) for Sharp LC-32LE340M LED TV:  The Power IC body size looks like smaller than the SMD zener diode Z7007! This power IC marking code is IDP-606, did you guess what's the IC part number is? The answer is........ => R7731AGE ! Below is the proof: We must refer to their product specification manual to confirm that this 6 pins Power IC IDP is a R7731A. Other 6 pins power supply SMD IC: 1) OB2263 = 63xxx                               2) LD7535 = WP
Read more

Collection How to Repair Hisense LCD/LED TV

Image
1. How to Repair TV No Signal and AV have Display but No Sound Problem Model: Hisense TLM2233 LCD TV Chassis: MST6 Symptom: When in TV mode, the screen shows NO SIGNAL. Try using the AV signal input, got display but no sound. Power on the Tv, screen display NO SIGNAL and it is showing the snow only. The whole Tv control on/off and other function normal. Try to search the TV channel and can’t find any TV signal! Changed to AV mode, the screen displays present perfectly but no sound. Even adjust the sound volume to maximum also not change. Check the TV tuner 5V ok but the 33V missing. Check their tuning boost feedback circuit 12V got 0V! Found the service manual and check their audio section was using the same 12V line too. So both symptom of this lcd tv was causing by this 12V line became 0V. So trace this 12V line on the mainboard and found this 12V line was supply from power supply secondary side and go through U23 (IRF7314) and reach to Tuner and audio section.
Read more

Collection How to Repair LG LCD/LED TV

Image
1. How to Repair LCD TV Auto Shutdown Randomly Model: LG 32LB9R-TB LCD TV Symptom: The TV will Auto Shutdown Randomly This is an LG 32LB9R-TB LCD TV. The problem was it will auto shutdown after 5 minutes or 30 minutes, sometime after 1 hours then power shutdown. When try to press again the TV power on switch, the Tv will directly shutdown again or after few seconds.  When using table fan to blow the Power Supply board (PSU), and using a piece of card board to block the wind blow to mainboard. The TV can last 2 hours still working properly. After that the table fan change to blow the mainboard and the card board block the PSU. The TV was shutdown just after about 8 minutes! This power supply board is an IP board, the part number is: EAY38637401. Even change the table fan blow the PSU, the TV can last longer to working! With this method, we know that the problem was inside the power supply board. So I can replace a working power supply board to solve this TV pr
Read more