It seems to me there was an issue on those involving a small 1/8 watt resistor right under the HOT that went from E to B I think. It would change value and alter the bias. Kinda late now, but will check for future ref. Phil Bader Gary McCartney wrote: > > Thanks to all the replies about this CTC187CN3 running hot. I have tried > all the parts suggested (except the flyback) with little or no > improvement. Because I can't afford any more time, I left the new parts > in and installed an extra heatsink above the HOT. Now after 9 hours of > running the set, the temperature is now only 36 deg. C. which is 20 deg. > cooler than without it. I explained the situation to the customer so > they know that a fault could reoccur in the future. They use the set in > the bedroom, so maybe it doesn't run many hours anyways. > > Gary McCartney > > McCartney Electronics > Guelph Ontario Canada > Est. 1984 > email: gary (at) number63.ca > > Webster TV wrote: > > > > Gary, > > > > You've replaced the parts that I usually have luck solving the overheating > > problem with, but I did have two other parts written down that could cause > > HOT overheating, so I'll give them to you also. C4303 and C4709. > > > > Dan Webster > > Webster's TV > > Shullsburg, Wi. > > ----- Original Message ----- > > From: "Gary McCartney" <gary@xxxxxxxxxxx> > > To: <techassist@xxxxxxxxxxxxx> > > Sent: Tuesday, December 16, 2003 4:45 PM > > Subject: [TechAssist] RCA TV model F32632SB chas. CTC187CN3 HOT runs hot > > > > > This 32" CTC187CN3 came in with HOT shorted. I replaced with OEM BUH517 > > > and noticed the HOT heatsink was running at 59 deg. C. (approx. 138 F), > > > measured directly on top of the transistor on the heatsink- which I > > > believe to be too hot. I remember having a couple of these sets that > > > were running cooler than that, maybe 45 deg. C. > > > > > > I tried another OEM BUH517 - no help > > > > > > Also replaced the following: > > > > > > -C4306 .047 250V > > > -hor. driver transformer -with new one > > > -R4402, 22 ohm > > > -R4305 4.7K 3W > > > -CR4402 > > > -CR4403 > > > -CR4106 > > > -C4403 0.55uF > > > -C4707 .041 400V > > > -C4409, 47 uF 35V > > > -C4402 .0157 uF > > > > > > I measure 139.2 V dc on cathode of CR4106 (B+) > > > HOT collector waveform is 1100V p-p no distortion noticed > > > waveform at base of HOT is 15V p-p and looks ok (manual calls for 12V > > > p-p but my scope may be acting up a bit) > > > > > > > > > Thanks for any help. > > > > > > -- > > > > > > > > > > > > > > > Gary McCartney > > > > > > McCartney Electronics > > > Guelph Ontario Canada > > > Est. 1984 > > > email: gary (at) number63.ca > > > > > > > > **************************************************************************** > > * > > > Lost Password: > > > http://www.tech-assist.org and select "Login Problems?". > > > Email Archives: > > > //www.freelists.org/archives/techassist/ > > > > > > > ***************************************************************************** > > Lost Password: > > http://www.tech-assist.org and select "Login Problems?". > > Email Archives: > > //www.freelists.org/archives/techassist/ > > -- > > ***************************************************************************** > Lost Password: > http://www.tech-assist.org and select "Login Problems?". > Email Archives: > //www.freelists.org/archives/techassist/ -- Philip Bader Jan Phyl TV Inc. (estab. 1976) 3420 Recker Hwy. Winter Haven, Fl. 33880 Fax (863) 299-8821 email: tjanphyl@xxxxxxxxxxxxxxx ***************************************************************************** Lost Password: http://www.tech-assist.org and select "Login Problems?". Email Archives: //www.freelists.org/archives/techassist/