Friday, June 10, 2016

Tech Troubleshooting Tips – Hum and Noise - Vertical bar - LED flashes constantly - Intermittent volume increase to maximum - Dark area in center of the screen- Vertical and horizontal lines - Samsung LN52B630N1FXZA- Samsung PN50B450B1DXZA- Samsung LN32B550K1FXZA - LN37B550K1FXZA - LN40B550K1FXZA, - LN40B550K1FUZA - LN46B550K1FXZA - LN46B550K1FUZA - LN52B550K1FXZA - Samsung UN55B8500XFXZA -Samsung LN40B530P7FXZA

Category: Led and LCD TV Repair and Service 

Contents of this article 

  • Troubleshooting tips
  • Verical and horizontal bar
  • Darken areas on LCD screen

Tech Troubleshooting Tips

TROUBLESHOOTING TIPS
When troubleshooting almost any product, be it an appliance or TV, take a bit of time to listen, look, smell, and touch the product before picking up a piece of test equipment to make measurements. By doing this, you can often narrow down the range of possible causes.
For example, if you’re investigating a plasma television failure, you can often find the area of initial failure by using at least one of your senses. You can also use the customer’s senses to help you find the area of initial failure by asking the customer questions about what he or she experienced at the time of the failure. Questions like “Did you hear any sounds or noise coming from the set?” or “Did you smell anything burning?” substitute the customer’s senses for yours and act as a trouble - shooting tool of the senses you can use, even though you weren’t there at the time of failure.
Asking the customer some simple questions might indicate that they “heard” a noise and “smelled” something burning. You then use the gift of eyesight to narrow down the search and, as in the Plasma TV example in the next column, find the burned out IC.

Listen for any noise that is out of the ordinary.
Look for any abnormalities.
Smell around for something that might have burned or overheated.
Touch the unit to feel if something is getting abnormally hot.
Ask the customer what he or she heard, smelled, saw, or felt.
Humming Noise and Scrolling Bar
A TV that’s humming and displaying a scrolling bar on the screen. To the trained tech, it’s easily identifiable as a common ground issue with the cable box.
1: Carry a spare line cord with the third pin removed
This is quick and easy. Remove the current power cord from the TV, insert your modified power cord, and then turn the TV on. The humming and scrolling should subside, showing the customer that the problem is with the cable box ground and not the TV. DO NOT LEAVE
YOUR MODIFIED CORD. This is for your demonstrations and you may need it further down the road.
2: Carry 3-prong-to-2 prong adapters
This really is a variation of Option 1. Unplug the TV, attach the adapter to the TV’s power cord, plug the TV back into the wall, and then turn the TV on. Again, the humming and scrolling should subside. Remove the adapter, and the humming and scrolling should return. Explain to the customer that if the TV had a problem, it would display the same symptom with the adapter attached. Since the symptom goes away when you attach the adapter, that proves that there is no problem with the TV, and the problem is with the cable box. Do not leave the adapter with the customer. You’ll need it for other demonstrations and tests, and you don’t want the customer to disable the grounding prong of the TV’s power cord.
3: Dig out your test DVD player
Remove the Red and White audio cables on the customer’s cable box, connect the audio cables from your DVD player, turn on the DVD player, and then turn the TV on. There should be no hum. Explain to the customer that if the TV had a problem, it would display the same symptom with the DVD audio cables. Since the symptom is gone, that proves the inputs are good and there is no problem with the TV. Reconnect the audio cables to the cable box and magically, the humming and scrolling line return.
Note that you can do this with any of the customer’s peripherals, but make sure you return the peripheral that you use to the customer’s preferred location before leaving the home.
4: Upgrade to HDMI
Perhaps the easiest and best option is to convince the customer to use HDMI. Not only would this provide better picture quality, it would also completely rid the TV of this symptom.
TECH TIPS 
Samsung LN52B630N1FXZA
Symptom: The LED above the power button flashes constantly and then flashes at a rapid rate when a command is sent using the remote control.
Solution
Check the LVDS cable.
Samsung PN50B450B1DXZA
Symptom: Vertical bar
Solution
Make sure it shows up in the front of the OSD and/or internal test patterns. If YES, replace panel.
Samsung LN32B550K1FXZA, LN37B550K1FXZA, LN40B550K1FXZA, LN40B550K1FUZA, LN46B550K1FXZA, LN46B550K1FUZA, LN52B550K1FXZA
Symptom: Intermittent volume increase to maximum. The TV volume will intermittently increase up to maximum (100 on screen) and cannot be controlled by the remote.
Solution
 Verify the product serial number range is between December 2009 and January 2010 and replace the front cover (bezel). The year and month of production is represented by the 8th and 9th digit. Possible affected units will be “SC” and “Z1”.
Samsung UN55B8500XFXZA
Symptom: Dark area in center of the screen.
Solution
Make sure it shows up in the front of the OSD and/or internal test patterns. If YES, replace panel.
Samsung  LN40B530P7FXZA
Symptom: Vertical and horizontal lines.
Solution
Make sure it shows up in the front of the OSD and/or internal test patterns. If YES, replace panel.