Sony Tv Codes

LED BLINKING CODES - SONY WEGA TRINITRON [HA - SERIES TVs]

No picture, No sound. Standby LED blinks six times or stays lit without any blink.

Suspected parts

[1] LOT [Line Output Transformer] [NX 4751 M34A]

[2] Horizontal out transistor [2SD 2624-CA]

[3] ABL [Automatic Brightness Limiter] resistors (R511, R512, R568).

      All part numbers will be printed on both sides of the printed circuit board.  Check ABL control resistors (R511,R512,R568, R513 & R510) for open.  If any one among them did fail, the main system control IC will sense it as an over voltage, and will give you indication as six blinks of standby LED.  Don’t misunderstood it to be an over voltage indication. Check components attached to pin number ‘2’ of LOT, before replacing it.

LOT fault detection

If 135VDC drops as set is switched ON

     Desolder out the horizontal output transistor [Q801 – 2SD2624-CA], and switch ON the set without it. Now check whether the voltage drops or not.  If not, replace the transistor with a new one, and switch ON the set for a short period of time, say 3 to 5 seconds.  Switch it OFF, unplug the set from AC mains, and feel the heat of the replaced transistor.  If it overheats within this short period of time, make sure that LOT is defective.

     If the voltage drops without connecting the horizontal output transistor, check [C807-330PF, C808-0082PF, C814-12KPF & C812-0.033Uf (yoke return capacitor), for any leak or other defects.  Check C811-1Uf 250V too.  Replace it with a new one.  If any of the low value capacitors indicated above gets opened, horizontal output transistor will get shorted as soon as we switch ON the set.  This is a common fault and should be checked well, if horizontal output transistor found shorted [Collector to Emitter leak]

   Before replacing the horizontal output transistor with a new one, check these capacitors, and replace them if suspected.  It is a best practice to replace these capacitors, along-with horizontal output transistors.  Check all the solder terminals at horizontal output stage circuit, for any loose or dry soldering.  Re-solder all the suspected solder terminals, by applying a little more solder, without making any solder bridge short between adjacent solder terminals.