Convergence
Hello diduni,
Yes you can use them but read this first:
I could not have said it better myself, I keep this around for times like this.
The various IC's have different specs, one important one
is the quiescent current. The higher number STKs have a higher
quiescent current (+10%) If you replace a STK 392-110 with an STK
392-150 the small value resistors will "smoke" in many cases and have
to be changed with different values. The
different TV Help blogs are full of people that have put in the "new
and improved" ICs then asked what to do now, all the resistors have
smoked or the unit will not start. Hitachi
has considerable information on the use of these ICs. In all cases they
tell you to change the resistors for different values, to allow for the
higher idle current. They also include information regarding alignment
for minimum idle current in the circuit. This relates to height, width
and hor/vert centre.
The design of the
TVs is ok, the IC's fail from AC power bumps or lightning (accumulated
damage to junctions over time). Semiconductors will run forever if they
have a smooth DC power source, are ventilated to operate within
temperature specs, and not overdriven. This was demonstrated when com
satelites were first used. They had estimated electronic failure in 4
to 6 years and many last 20+ years. They are replaced when they run
out of manouvering fuel or get an induced power surge from the sun.
When the IC's run too "hot". there is usually a low ohm resistor that
has increased in value and causes higher current output from the chip
through the feedback in the circuit design. The resistor(s) may have
changed from 1.8 ohms to 2.5 ohms, the TV will still run, but the IC
will fail prematurely.
STK 392-110 will
work fine if all the small value resistors are ok and the TV is not
subjected to a hotter environment than normal or power line related
troubles. Many RPTVs are mounted in enclosed areas with no air
circulations or in direct sunlight. These situations will cause the
unit to operate at raised air temperature around the IC's resulting in
more failures. Some people have "hotter" houses than others, their
convergence IC's will fail sooner.
If
you can redesign the convergence circuits and waste your time replacing
all the low ohms resistors, go for it. Otherwise use the STK 392-110,
or whatever the manufacturer had in the unit.
I know from experience. When Hitachi came out with "new and improved"
replacement ICs we installed many STK 392-120 for STK392-110 in Hitachi
and other makes. The result was many burnt resistors, many call backs
and big expense. The same applies to the Samsung STK392-010 or STK392-040. Use the original IC.
This was borrowed from:
http://www.techlore.com/forum/thread/22290/Rear-projection-TV-STK-392-120-LG-convergence-problem/
from: easyab
I hope this helps
Shuttle83
http://www.electron-age-technologies-llc.com
thank you very much............i used metal oxide resistors
i went to repair and found 4/6 resistors way out of value so i changed 4 of them...........powered tv on and everythign worked except the blue would not move up/down...........i even changed the stk all new....i was stumped so i checked resistors and found that one of the new res i changed was no good....i found out all my 1.5 ohm res were bad straight from ret package lol
so i had to buy another package and the tv worked great now
lesson learned...new does not always mean good....always check before you install new parts...new can be bad too lol
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