David, Q601 is called the on/off the baseo it goes to u601 the cpu pin 20 thru r629 (3300 1/8 watt ). on one side of that resistor you should have +5 volt standby. The base of Q601 ties to r671 (4700)to the collector of Q606 called the switch and that shows to have +5 volts standby on the emitter of this Q606. The base of the Q606 goes thru r673 (100k) thru c 676 (33uf 16v) and the neg end of this cap shows to have +5 volts run on it. John Conti,TV Texas >From: "David Lessard" <mr_fixit@xxxxxxxxxxxx> >Reply-To: techassist@xxxxxxxxxxxxx >To: <techassist@xxxxxxxxxxxxx> >Subject: [TechAssist] Re: [TechAssit] RCA - 27" TV - PMR623ER - CTC130A - >Dead - Shorted HOT >Date: Mon, 17 Oct 2005 22:34:18 -0400 > >Gentlemen, I am truly confused! I've checked all tips mentioned by you >wonderful guys, tips that have obviously been around for awhile as this >chassis is 25 years old. I still can not find the problem. This TV cycles >ON/OFF about every 3-5 seconds once the "PWR" on button is pressed. I'm >missing some of the schematic Max sent over, the part that contains >information about Q601. I need to study this part of the circuit a bit more >to confirm what may be going on here. When I press the "PWR" on button I >see >minimal activity at the base of Q601. Where does the signal come from that >drives this transistor, perhaps the mystery lies here. Thanks for all the >tips and advice, if anyone has information about Q601 please send it along. >Of course any other tips would be greatly appreciated. BTW I don't normally >spend this much time of a TV, its become a learning thing at this point. >David Lessard. Alexandria, Ontario, mr_fixit@xxxxxxxxxxxx > >----- Original Message ----- >From: "John Conti" <contitv@xxxxxxxxxxx> >To: <techassist@xxxxxxxxxxxxx> >Sent: Friday, October 14, 2005 5:14 PM >Subject: [TechAssist] Re: [TechAssit] RCA - 27" TV - PMR623ER - CTC130A - >Dead - Shorted HOT > > > > David, just a few things to check,c115 (68uf) check r 115(36k) > > cr105,cr408....also check r16 (1.5 ohm)p/n 175331 in the drain terminal >of > > Q1 VIR out for increase in value. This is a critical resistor. also c7 > > (68uf) c11 (150uf) can cause this problem. And c 108 (.22uf) Hope this > > might help. > > Also if that does't help check all solder connections on the mtt001 or >002 > > module. > > > > John > > Conti,sTV > > Texas > > > > >From: "David Lessard" <mr_fixit@xxxxxxxxxxxx> > > >Reply-To: techassist@xxxxxxxxxxxxx > > >To: <techassist@xxxxxxxxxxxxx> > > >Subject: [TechAssist] Re: [TechAssit] RCA - 27" TV - PMR623ER - CTC130A >- > > >Dead - Shorted HOT > > >Date: Fri, 14 Oct 2005 15:24:09 -0400 > > > > > >Follow-up: > > > > > >Replaced HOT, and R426 horizontal drive +B, resistor value was up by > > >800ohms. TV pulses ON/OFF when ON" button is pressed, TV comes on for a > > >brief second as power cord is unplugged. I've replaced C672, C654 and >C656. > > >When I disconnect RED wire on standup board next to VIPUR TV pulses >ON/OFF. > > >What am I missing? What are the start conditions for this chassis to > > >fire-up? I know nothing about this 25 year old chassis. Thanks in >advance. > > >David Lessard, Alexandria, Ontario. mr_fixit@xxxxxxxxxxxx > > > > > >----- Original Message ----- > > >From: "Phil Bader" <tjanphyl@xxxxxxxxxxxxxxx> > > >To: <techassist@xxxxxxxxxxxxx> > > >Sent: Monday, October 03, 2005 9:57 PM > > >Subject: [TechAssist] Re: [TechAssit] RCA - 27" TV - PMR623ER - CTC130A >- > > >Dead - Shorted HOT > > > > > > > > > > Yes. > > > > Dead,5A fuse blown. Fix: Shorted cap C425 (043uf@200V) yoke return I > > >think. > > > > > > > > After you get it on, here's some issues you may face: > > > > Brightness a bit exessive,retrace: C122 (30uf@250V) front of >flyback. > > > > Raster narrow at sides, slight bow: Q1 on pincushion upright board >near > > > > rear of chassis. RCA#146847/2N2222A,checks OK-replace it. > > > > Channels 2-6OK, no 7-13. Open and resolder all stakes inside the >MTT001 > > > > module. > > > > Bands of interference (two) slowely moving up thru picture.: Inside >the > > > > MTT001A, change C654(100uf/16v),C672(220uf/25V),C656(330uf/10V). > > > > Immediate shut down at turn on:Flyback bad. > > > > Vert. retrace at top inch of screen.All assoc. caps seem to ESR OK. > > > > R506(6800ohm/2W) runs hot normally.Remove,scrape leads and resolder. > > > > Left side jailbars: Workaround: Add a 10uf/250V cap across CRT's PC > > > > board's stakes, pos. to "C6", neg to "Z1".(saves pulling chassis) > > > > Excess brightness: C122 (47uf@250) > > > > Unusual brightness issue: Increase brightness with control,all >sudden >at > > > > max: R721 (680ohm) increased to 690ohm. Also: Q703 shorts > > > > (#143806/NTE159).HTH. > > > > Phil > > > > > > > > Philip Bader > > > > Jan Phyl TV Inc. (estab. 1976) > > > > 3420 Recker Hwy. Winter Haven, Fl. 33880 > > > > Fax (863) 299-8821 > > > > email: tjanphyl@xxxxxxxxxxxxxxx > > > > personal/ alt. email: pbader@xxxxxxxxxxxxxxx > > > > see our ad at: > > > > > > > >http://jan-phyl-television-pc-monitor-service.9601288257006.worldpages-ads. >c > > >om/ > > > > > > > > > > > > > > > > David Lessard wrote: > > > > > > > > >This TV has a shorted HOT (C1308K), main fuse is blown. Are there >any > > >common problems besides a bad flyback which could cause this? > > > > >Thanks in advance, > > > > >David Lessard > > > > >Alexandria, Ontario, Canada > > > > >mr_fixit@xxxxxxxxxxxx > > > > > > > > >--------------------------------------------------------------------------- > > >-- > > > > >This Email List is accessible to the general public through search > > >engines. 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