Hello,

We are having difficulty with a 32" Sony Consol. Original problem was the tv was dead. Found defective (2)2sc4664, 2SC4927, and open fuse. Replaced parts. TV works for about 15-30 minutes and parts blow up again. The heat sink is VERY hot. Anyone have ideas as to what causes the power supply to get hot and break down? We had troubles with this chassis in the past and I found this forum today. Any help would be appreciated. Set was manufactured FEB 1993.

thanks
Scott
PTV

KV32TW75 (chassis LN-1). repeat failure of the components u replaced can be caused by bad solder connections "solder joints" on the horizontal drive transformer. heat sinks do get hot, but not very very hot.

also there is a chance the FBT is going out.

I forgot to ask if u got an original 2SC4927 (original transistor is made by hitachi). there is a lot of generic 2SC4927 in the market stamped with the hitachi logo.

The SONY part number for 2SC4927 is 8-729-016-32

We are using generic 2sc4927(only $3). We have been using them for all sony repairs and never had a problem with them. Does this chassis require the original? I'm hesistant to buy $15 transistors if they are just going to continually blowup. The heat sinks for the 2sc4664 get very very hot. I'll check for the cold solder.

thanks
Scott

generic 2SC4927 works okay with 27". yours is a 32" TV

The parts that continue to fail are the 2sc4664 transistors. The horizontal output (2sc4927) does not blow after we replaced it the 1st time. We have gone through about 6 of the 2sc4664 and 2 of the 2sc4834's. Everytime they fail within 15 minutes. Fuse is still good and horizontal output is still good. Is the generic output causing the 2 transistors to continually go out?

thanks
Scott

Rule of thumb states that if the transistor is getting hot its a drive issue, resistor high drive transformer short etc if the flyback is faulty it tends to work ok then crash. Tip I use for testing these awkward faults is use 2, mount one on a heatsink above the other and parallel them. I use this for some of the very expensive old sanyo transistors and have had no issues.

I had this experience in the past,only C4664 went out shorted,the problem MUST BE in the power supply(diode,cap,resistors that have lost their value).I couldn't finish this repair becouse customer decided to buy a new one.

Scott,the only way to find out is by using original 2SC4664.
I have the schematic of KV-32TW77 chassis SCC-F84F,G,K-A if you need it,let me know.I noticed that this set uses 2SC4834N and must be original.In my repair notes,I listed not use generic parts and if you get the "N" on such trans,must be using original.

thanks for the help guys. I ended up putting a newer chassis in the set. My customer jsut loves the cabinet so we had to come up with something to get it to work. My patience is done with this chassis. I dont think I will be taking these in anymore.

Hi I have the same priblem with my TV I replaced all the part and TV work well for 3 day then it happen again same part are burn with the fuse blow..

any suggesting...

PS can I you send me the schematic..

Thanks
JJ

I have a Sony KV32TW75 with the same problem can any one help...