Friday, October 4, 2013

TV Common Problems - repair tips

DEFECT: Single Vertical Line In The Center
POSSIBLE HINTS : 
1.) Check first the vertical IC. Some Vertical IC’s may have loose contacts on solder joints on its legs because of the heat and cold condition on its operation.
2.) Check the supply voltage if present in the main vertical section, sometimes 24 volts from the flyback and other supplied by 24v and -24v plus ground.
3.) If the supply voltage is missing, check the line from flyback having 18-24 volts, possible culprit is an open fusible resistor.
4.) Defective yoke, maybe there is a broken or burn part of the coil inside it.
4.) If the supply voltage is present, possible problem is that the Vertical IC is defective or the Vertical Sync coming from the Jungle IC, better to check also the jungle IC in this situation.

DEFECT: HORIZONTAL LINE ONLY
POSSIBLE HINTS :
1.) Defective yoke, maybe there is a broken or burn part of the coil inside it.
2.) Loose contact connection on one of the legs of the yoke on the main board.
3.) Defective non electrolytic capacitor.


DEFECT: NO SOUND
POSSIBLE HINTS :
1.) check first your speakers, it is usually the most common culprit after repairing a television with power supply problem based on my repair experience.
2.) Check if the supply voltage for audio ampifier is present, if not check the line.
3.) If the supply voltage is present, try doing a hum test by touching the input of the audio IC, refer to the datasheet to find the input pin of the IC. Replace the audio IC if everything is done.
DEFECT : NO POWER
POSSIBLE HINTS :
1.) Check first the power cord.
2.) If the power cord is ok, check the fuse
( note the fuse is burnt, don’t replace it right away. Check first the circuit if their is a short on the circuit specially on the primary power section, check all the diodes surrounding the main power IC)
3.) If their is no shorted diode and no short on main IC, now check the Horizontal Output if it is busted or shorted.