Dale,The diode Gary is referring to is D452.This is from Tech Bulletin #PB94-05.This diode ''MUST'' be removed.Also check/replace Q551,D816,IC451,IC2301.Also on all GL7C series chass. resolder T501.When replacing IC801 spread the retaining clip tab to insure it holds the IC tightly against the heat sink....Don.... HARTS-TVCR''ASC'' 9 Robert St.,Oromocto,NewBrunswick,Can E2V 3N2 Tel#506-357-9785,Fax#506-357-6010 hartstv@xxxxxxxxxxx ----- Original Message ----- From: "Gary McCartney" <number63@xxxxxxxxxxxxx> To: <techassist@xxxxxxxxxxxxx> Sent: Tuesday, September 17, 2002 8:53 PM Subject: [TechAssist] Re: Panasonic CTV # CTK-2790S, Chassis# AEDP152 or GL7C Repeat IC801 failure > > Dale, I had a similar problem with my own TV, only it is the 31" version > of the same chassis. > I'll send you the information I have. Mine would blow the reg. about > once per month rather than after 2 minutes. Finally I noticed a trace > blown open, and from memory I believe it was from one of the STR60001 > reg. pins to zener D805, thereby effectively removing D805 from the > circuit altogether. There is also a diode which is to be removed from > the circuit if it is present. I'll do a bit more research to find that > info for you. > > > > Gary McCartney > > McCartney Electronics > 7134 Fife Rd, RR 7 > Guelph Ontario Canada N1H 6J4 > Fax: (519)821-1530 > email: number63 (at) inetsonic.com > > > > > > > > HarrisTV50010@xxxxxxx wrote: > > > > We have a Panasonic CTV Model# CTK-2790S Chassis# AEDP152 or GL7C. This unit > > came in with the complaint of popped and went dead. We found C821, IC801 & > > D805 shorted. Q801 has a hole blown out of it and R826 was open. > > We replaced C821, IC801, D805, Q801, R826, C807 & R825. After replacing these > > parts the set worked for a couple of minutes with all the proper voltages > > coming out of it. Then it suddenly went dead. We found IC801 had gone bad > > again. We replaced it, shorted the power relay and slowly brought up the AC > > going into the set. The B+ coming out of the secondary of the switching > > transformer T801 are normal. The IC starts to get hot. The waveform on the > > collector (pin 3 ) of IC 801 seems normal except the frequency seems to > > quiver too much and the base (pin 2) of IC801 is supposed to be 14v p-p but > > we only get about 4v p-p with the same frequency quivering as the collector. > > We have checked every other part on the primary of the power supply and > > everything seems OK. Sorry for writing a novel about this unit. Does any one > > have any notes on possible problems with this power supply? > > > > TIA, > > Dale > > > > Dale A. Lubow... HarrisTV50010@xxxxxxx ..515-232-1109..(Fax)515-232-3356 > > Harris TV & Appliance..........335 Lincoln > > Way.....Ames.....Iowa.....50010-3384 > > > > ------------------------------------------ > > 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 > > ------------------------------------------ > > ***NEW*** Tips Added Instantly!!!*** > > Submit Repair Tips here: > > http://www.tech-assist.org/secure/tip/ > > -- > > > > Gary McCartney > > McCartney Electronics > 7134 Fife Rd, RR 7 > Guelph Ontario Canada N1H 6J4 > Fax: (519)821-1530 > email: number63 (at) inetsonic.com > ------------------------------------------ > 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 > ------------------------------------------ > ***NEW*** Tips Added Instantly!!!*** > Submit Repair Tips here: > http://www.tech-assist.org/secure/tip/ ------------------------------------------ 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 ------------------------------------------ ***NEW*** Tips Added Instantly!!!*** Submit Repair Tips here: http://www.tech-assist.org/secure/tip/