LCD IS NOT BRIGHT {Click on images to Enlarge}
First, check cables which connect with Power Supply Unit [PSU] then check as follows
- Check input voltage (CNA1)
- Check output voltage (CND1)
First check cables, which connect with PSU then check as follows
- Check input voltage as NO picture
- Check speaker output.
POWER SUPPLY UNIT FAILURE
First, check cables, which connect with PSU, then check as follows
- Check PSU input voltage AC input (CON1)
- Check PSU output voltage orderly (CON2)
FAILURE SYMPTOMS
Block Defect :TCP cracking or cracking
Dim or L/D :TCP Sunken
TCP lead cracking
ACF bonding short
Awful environment and something electric enter into
LCD
Mis-align between TCP and Panel
Panel failure
TCP failure.
Dot Defect.
- Bright dot dark dot in panel.
- Panel or Polarlzer.
- Polarizer Bubble.
Bladder between Polarizer and top glass.
- Polarizer Scratch.
Tine or rigidity arose.
- F/M inside Polarizer.
Abnormal Display. Flashing. Bright and dark display alternately.
- Chip lose action
- IC Abort or jointing bad
- Panel and VSC connect bad
- White Screen. B/L normal, only white screen display.
- Black Screen. B/L normal, only Black screen display.
- Maybe caused by surge current and EDS.
- FIicker or Crosstalk. è LCD Vcom imbalance.
Abnormal Color. Capacitance improper bring crosstalk inside LCD panel. [OR]
- Chip lose action.
- IC short or joint bad.
- Panel and VSC connect bad.
- Mechanlcal Noise. èCaused by Mechanica noise of backlight unit.
- Ripple. Connectric circle. è Causeed by between mechanism and Panel.
- B/L off. B/L lose action.
- B/L dark.
- B/L wire damaged. Operation abnormal or systemic noise.
- B/L wire open. Operation abnormal or systemic noise.
- B/L shut down. Short between lamp housing and wire, because consume power too much.
F/M. F/M in B/L ,white, back Rotundity or wire like. è F/M in B/L unit.
Light leakage. Brightness at bottom of LCM brighter than normal. è B/L unit badness.
Mechanical or B/L. B/L brightness asymmetric. è Sheet in B/L unit is uneven.
The above given screenshot can be taken as a reference to most of the flat panel televisions.
[B/L > Back Light.]
[F/M > Frequency Modulation]
[PSU > Power Supply Unit]