Bob, Thanks so much for your reply. With a bit of embarrassment, I was interrupted several times while trying to post this problem that I failed mention I already replaced IC400 and IC402. I also replaced C459 and C431. I also resoldered the usual poor solder joints that these sets all have. I checked as suggested, C421, C430, R427 and R428. My voltages on Q433 are: C=9.2 B=0 E=0 this is with the set in the "on" mode. C=8.4 B=.6 E=0 this is in the "off" mode. There is 9.4v on P2 of IC402 with no change in voltage in "on" or "off" mode. I would definitely say that IC402 is the culprit but I did already change it to no avail. You mentioned that the 483513097005 replaces 5303000001. Is this possibly an upgrade for this problem as I had the old number in stock. This seems to be the only problem with this set. Everything else is working properly. Again, thanks for your help. Daryl Daryl's TV 3310 Dyer St. El Paso, TX 79930 915-565-9184 915-564-1024 Fax http://dynacomp.freeyellow.com -----Original Message----- From: Gemini Computer & TV <geminitv@xxxxxxxxxxxxxxxx> To: techassist@xxxxxxxxxxxxx <techassist@xxxxxxxxxxxxx> Date: Thursday, January 02, 2003 6:37 PM Subject: [TechAssist] Re: Magnavox RK5554, 27P1 ch....can't turn off > >First thing to do is replace IC402 (optoisolator IC). It is part # >483513097005 (formerly part# 5303000001). If that does not take care of it, >then check Z430, C421, C430, R427, R428, Q433, and IC400. I am almost >certain this should cure it. let us know how you make out. > >Bob Waterman, CET® #RI-28 >Master Technician License #9109 >Service Manager >Gemini Computer, TV, & Security Alarms >(508)695-7302 >(508)695-7769 FAX >geminitv@xxxxxxxxxxxxxxxx >geminitv@xxxxxxx > >----- Original Message ----- >From: "D Thunhurst" <dthunhurst@xxxxxxx> >To: <techassist@xxxxxxxxxxxxx> >Sent: Thursday, January 02, 2003 7:50 PM >Subject: [TechAssist] Re: Magnavox RK5554, 27P1 ch....can't turn off > > >> >> Thanks for the reply. >> Is this the famous 100@200v cap you have reference to? If so, this set >> doesn't use it. C432 on this set is a .1@50v cap. >> Daryl >> Daryl's TV >> 3310 Dyer St. >> El Paso, TX 79930 >> 915-565-9184 >> 915-564-1024 Fax >> http://dynacomp.freeyellow.com >> -----Original Message----- >> From: TV Doctors <tvdoctors@xxxxxxxxxxxxx> >> To: techassist@xxxxxxxxxxxxx <techassist@xxxxxxxxxxxxx> >> Date: Thursday, January 02, 2003 4:55 PM >> Subject: [TechAssist] Re: Magnavox RK5554, 27P1 ch....can't turn off >> >> >> > >> > >> >Change C432 >> >-------Original Message------- >> > >> >From: techassist@xxxxxxxxxxxxx >> >Date: Thursday, January 02, 2003 01:59:09 PM >> >To: TechAssist >> >Subject: [TechAssist] Magnavox RK5554, 27P1 ch....can't turn off >> > >> >Hi, >> >This Magnavox is eating my lunch. The set comes on at plug in. The relay >> >is used solely for degauss. The on-off circuit is controlled by the micro >> >and is giving me "0" volts in the "on" position and ".6" volt at turn >off. >> >I have replaced Q430, Q431, Q432, Q433, Z430, R437, C435, and C436. >> >The schematic shows that the base of Q432 is connected to the micro and I >> am >> >getting the biasing on that transistor (marked as on-off switch). >> >This set is very sensitive to temperature. When components are heated, >the >> >set can be turned off. >> >A simple solution you say?? I thought so too!! >> >Every component I stated I replaced was because when I would place the >tip >> >of the soldering iron just close to each of the various components, the >set >> >would function properly. Freeze the parts and the set could not be turned >> >off. >> >I even mounted the parts in question on the bottom of the board as not to >> >heat or cool any other part and thought to have confirmed the culprit. >> >After replacing the part or parts in question using OEM parts, the same >> >symptom occurred, even with the new parts, absolutely no change. >> >I am now at a loss as I have replaced or subbed every part that was >> effected >> >by heating and cooling. Now I know how a new born calf looking at a gate >> >must feel. >> >Any ideas or advice would be appreciated. >> >Thanks >> >Daryl >> >Daryl's TV >> >3310 Dyer St. >> >El Paso, TX 79930 >> >915-565-9184 >> >915-564-1024 Fax >> >http://dynacomp.freeyellow.com >> > >> >------------------------------------------ >> >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 > > ------------------------------------------ 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