Sony Blinks

SONY TRINITRON [KV20 - KV21 SERIES] [BA-4D CHASIS]. Fault - Continuous blinks of standby light, No Pause

   

Continuous blinking of standby light with this models Sony sets
indicates that there is some short or data missing from serial data from
system control IC (001 – M37273MF-252SP). Pin number 38 of this IC is
Serial Clock, and 37 are serial data output.  Check the voltages at
these two pins. Check the voltage at pin number 37.  It should be around
3.5 to 4.3 VDC.  If you have an oscilloscope or a millimeter which can
measure frequency. Check the digital waveform or frequency with it. All
other functions of this TV is controlled by these two signals emerges
from the above said two pins of the IC.  If it found Ok, surely the
memory IC (IC003-M24C04-MN6T) is faulty.  Replace the memory IC with
same type and number.  When you replace this IC, insist on same number,
otherwise set won’t even refuse to switch ON.  Check the oscillator
crystal (X001) soldered to pin number 25 of the main system IC.  Check
the frequency at pin number 25.  If it is found abnormal than specified,
replace the oscillator crystal. Check the resistors connected to pins
37&38 [R003 & R032] respectively, for continuity.  If all of
these are OK, and still fault is there, check all the solder terminals
of this main system control IC, for any dry solder, or loose solder.

Normally, a loose solder to IC terminals are very difficult to
detect, as it will be very microscopic, as we cannot detect it without
the help of a magnifying glass.  The best practice is, to resolder all
the soldering of this IC, by applying a little more solder, without
making any solder short bridge in between adjacent solder terminals. 
You must have a concept of soldering, and steady hand to do this work. 
More important is the patience and concentration.

If you want the service manual to this set, contact me by email, if this set allows you to do so.