David I've seen this before and it ended up being C3301. Pin 63 of T chip is where it comes out of, I have Q3301 for sync amp, 5.5V =B, 5V=E, 8.5=C.Check pin 38 on micro for pulse, the one I had wasn't shaped right and the amplitude was low. Manual calls for 2.4V. al marquardt ampm@xxxxxxx ----- Original Message ----- From: "David Lessard" <mrfixit@xxxxxxxxxxx> To: <techassist@xxxxxxxxxxxxx> Sent: Thursday, January 02, 2003 2:45 PM Subject: [TechAssist] Re: GE 27GT614JX1 Chassis CTC177BE > > Wayne: > > Thanks, your reply was very thorough, I love learning new stuff! You > described exactly what is going on with this TV, in that it searches cable > channels (14 - 125), finds nothing, then searches air channels (14 - 69), > finds nothing, then sits there at channel 3. Either the tuner is not working > or the values aren't being stored. The scan time per channel is about 500ms, > so I would assume the problem is not with the tuner. The horizontal sync > pulses start from where? The tuner, sync seperation circuit, to which pin on > the micro? I will look at Q3305 buffer, what voltage values should I expect > to see here? Any other thoughts on this? > > Thanks. > > David Lessard > Alexandria Electronics > mrfixit@xxxxxxxxxxx > (613)525-4502 > > -----Original Message----- > From: techassist-bounce@xxxxxxxxxxxxx > [mailto:techassist-bounce@xxxxxxxxxxxxx]On Behalf Of Wayne Vanaman > Sent: Thursday, January 02, 2003 2:28 PM > To: techassist@xxxxxxxxxxxxx > Subject: [TechAssist] Re: GE 27GT614JX1 Chassis CTC177BE > > > > David: > > The Thomson/RCA products in general start autoprograming at channel 14 to > determine if they are connected to cable. Although some will go all the way > to 125 some will only go into the 30s or so. (They have been doing this > since about the ctc13x line) If no channels have been found by then they go > back to ch2 and in the Air position. Normal operation would be, then, > 14-125, 2-13, retune the last channel the set was on. In the "air" mode, > 14-something, then 2-69, retune the last channel. > > This way they don't need to be told Air or Cable. > > The channel is determined to be there if the horizontal sync pulse reaches > the microprocessor. Unlike many other brands that look for the 3.58Mhz > burst. This way if the Horizontal sync pulse has been suppressed, as in > cable company premium channels, the channel is determined to not be there, > and is not stored in the scan list. Who wants to watch that anyway? > > A key here is that the sync pulse must reach the micro. If the product is > autoprogramed and the sync pulse does not reach the micro, or the micro is > defective, the set will default to the Air position with NO channels stored > in memory. The set will tune the channels if entered from a remote control. > The set can be put into the cable mode and the cable channels then direct > entered. Here is another clue: If the tuning is Slow (most Thomson > products will tune in the 200-400mS time frame), that is, it takes a second > or so to tune, then the sync pulse is not reaching the micro. The most > common cause of this is the failure of SMD Q3305. > > In your specific case, what is the problem. > > > Wayne Vanaman > Omega Electronics > 6904 W Fairfield Dr > Pensacola, Fl. 32506-3310 > > Wayne@xxxxxxxxxxxxxxxxxxxxx > WWW.PensacolaTVRepair.Com > > 850-456-5995 voice > 850-458-6369 fax > ----- Original Message ----- > From: "David Lessard" <mrfixit@xxxxxxxxxxx> > To: <techassist@xxxxxxxxxxxxx> > Sent: Thursday, January 02, 2003 1:02 PM > Subject: [TechAssist] GE 27GT614JX1 Chassis CTC177BE > > > > > > Hi Techs, > > > > Haven't worked on a lot of these, tuner doesn't seem to function properly. > > When autoprogramming, channels 2 - 13 are skipped, it starts scanning at > > channel 14 up to 125. Audio is good. I can see the tuner was reworked > > (famous tuner shield problem). Is the problem likely the tuner control > IC?. > > I have no information on this chassis. Any information would be greatly > > appreciated, schematic or tips. > > > > Thanks Gentlemen. > > > > "Share what you know, Learn what you don't" > > > > David Lessard > > Alexandria Electronics > > 50 Harrison Street > > Alexandria, Ontario > > K0C-1A0 > > mrfixit@xxxxxxxxxxx > > > > ------------------------------------------ > > Submit A Repair Tip For Everyone Here: > > http://www.tech-assist.org/secure/tip/main.html > > ------------------------------------------ > > To REMOVE your email address, click here: > > http://www.tech-assist.org/unsubb.html > > To CHANGE your email address, click here: > > http://www.techassist.net/forms/change.html > > > > > > ------------------------------------------ > Submit A Repair Tip For Everyone Here: > http://www.tech-assist.org/secure/tip/main.html > ------------------------------------------ > To REMOVE your email address, click here: > http://www.tech-assist.org/unsubb.html > To CHANGE your email address, click here: > http://www.techassist.net/forms/change.html > > ------------------------------------------ > Submit A Repair Tip For Everyone Here: > http://www.tech-assist.org/secure/tip/main.html > ------------------------------------------ > To REMOVE your email address, click here: > http://www.tech-assist.org/unsubb.html > To CHANGE your email address, click here: > http://www.techassist.net/forms/change.html > > > ------------------------------------------ Submit A Repair Tip For Everyone Here: http://www.tech-assist.org/secure/tip/main.html ------------------------------------------ To REMOVE your email address, click here: http://www.tech-assist.org/unsubb.html To CHANGE your email address, click here: http://www.techassist.net/forms/change.html