You should always replace BOTH convergence IC's at once unless you want to have to go into the TV set again within a few months or so. Blue-star as I understand it, is not the best place to purchase these convergence IC's from. They are very inexpensive at blue-star but that is part of the problem. I always buy mine from http://www.electronic-repair-kits.com/index.html Also, before you install the new IC's, install thermal paste to the backs of the new IC's. Good Luck

"Those who do not know their opponet's arguments, do not completely understand their own".

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The STK392-150 or STK392-180 are no better then the STK392-110 the STK392-120 is better BUT if you Want the VERY Best IC use the STK394-160

The STK394-160 is the NEW STK that Replaces the OLD STK392-110,120,150,180 IC'S The STK394-160 Runs MUCH Cooler !

unless your an engineer and have ran test on these circuits using these IC's would not recommend using these IC's as these sets go through united laboratories rigorous testing using the original IC"s that the manufacture recommends. and changing or modifying a circuit could also void your homeowners insurance, in case there was an fire or something like that yes I Have certainly used different unauthorized parts in a set in the past but I do not make it a habit nor would I recommend someone to do so as well.

"Those who do not know their opponet's arguments, do not completely understand their own".

ALOVRU said:

Dwray said: The STK392-150 or STK392-180 are no better then the STK392-110 the STK392-120 is better BUT if you Want the VERY Best IC use the STK394-160 The STK394-160 is the NEW STK that Replaces the OLD STK392-110,120,150,180 IC'S The STK394-160 Runs MUCH Cooler !

Thanks i have ordered the STK392-120, i would realy like to use the STK394-160 but i have not heard of anyone using them with the LG's yet. (don't want to make things worse) dumb question but do the convegence boards run AC or DC? i'm thingking of putting a pair of 12v DC fans to keep things a bit cooler.

Dwray said: STK392-110 is rated 3amp STK392-120 is rated 4amp STK392-150 is rated 3amp STK392-180 is rated 3amp The higher the Amp rating The Cooler the IC will Run and last longer

I believe the above statement is misleading and could be costly.  It is not the same as a higher rated fuse or a brighter lightbulb.

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. 

easyab

thanks for all the help/advice guys, it's all fixed now. i replaced both ICs with original Sanyo STK392-120 from http://richtechparts.com/i-24-STK392_120.html and did a fan upgrade to the convergence board. i put an 80mm 12v arctic cooling fan on each heatsink (fits perfect) and ran a 12v regulator also used Tuniq TX-2 thermal compound for better heat transfer.only two resistors were affected, but were well within 10% of spec so there was no need to change.