To eliminate one circuit as being the culprit, pull the plug from the audio board. I believe its J/P1906 or 1904(not at the shop). Then see if it fires up. Jonas Miglinas Miglinas TV Chicago ----- Original Message ----- From: "Larry E." <videotech@xxxxxxxxxxxx> To: <techassist@xxxxxxxxxxxxx> Sent: Thursday, July 24, 2003 6:56 PM Subject: [TechAssist] Re: RCA-CTC169AM,chass-f31221wn-32'' > Hi Don, you need to be carefull changing parts in a 169 chassis with a pa= > rts list from a 27" proscan, there are 4 different families of 169 chassi= > s`s and some of the parts > are very different, for example C4108 in your set (family 1) is supposed = > to be a > 47uf @ 50 volts but in a family 4 169 it`s a 39uf @ 100v, BIG difference= > =2E > The usual cause of pin 16 on U4101 fluctuating up and down is the 3 caps = > you changed, or U4101 is bad check the values, C4102=3D 2.2 @ 100v C410= > 4=3D 4.7 @ 100v(not 47uf) C4108=3D 47uf @ 50v. If those are good then th= > e set is either in ovp or ocp You should have the following in standby (s= > et plugged in but not turned on), Raw B+ on C of Q4101 =3D approx. 165 vo= > lts, Regulated B+ on C of HOT=3D approx.144 volts, 5v standby on E of Q46= > 01. If the above are correct, check voltage on pin 3 of U4101, it shouldn= > `t be above .6v (point 6 volts) if it is the > set is going into ocp shutdown. Let me know the results of these measurem= > ents, > I don`t have a scanner but I do have the schematics and 169 troubleshooti= > ng guide. > Remember that a lot of the capacitor values are different for the various= > 169 models > so be careful to replace what you pull out with the same value, Larry E > Larry Eastman > American TV & Electronics > Crystal River, Fl. 34428 > 352-795-0124 > pulling out > hartstv@xxxxxxxxxxx wrote: > > > This direct view 32'' unit has me baffeled.Orginally came in with the H= > OT shorted.Replaced with an OEM 2SD1885.Everything else was ok so fired i= > t up.The HV was 38.5KV,too hi,so took the chass out to bench test.Turned = > it on without a yoke plugged in & I think that's when my problems started= > =2EQ4802 smoked in the pin cct.Replaced it & plugged a yoke to the set.No= > w my smps won't start.Pin 16 reads 8.5vdc then slowly goes up to 10.5vdc = > & then starts going back down to 8.5v.So changed all the normal parts for= > this smps,ie,the U4101,C4102,4,8,Q4101.Did not help.Replaced the infamou= > s CR4118.Checked or replaced both LM311 in the vert & pin cct;also C4403,= > CR4401,CR4402.Again no go.Checked or replaced all trans in the PWM cct,Q4= > 405,6,7,8,9.Same results;the regulator is trying to start but keeps going= > up/down from 8.5v to 10.5v.Raw B+ is solid at 165vdc,no ripple.All these= > tests were done with HOT collector lifted.I have checked all my tips for= > this unit,& I know there's a ton of them but > > can't find the problem.I have changed so many parts too numereous to = > mention,ie caps,diodes,transistors but I'm stumped.Any assistance would b= > e greatly appreciated or if someone would be so kind to email a pdf for t= > his brute.The only print I have is a profax for the 27'' set.BTY i also c= > hecked all transistors in the Q4300 & Q4700 series.........TIA...........= > =2E > > Don of HARTS-TVCR-ASC > > 9 Robert St,Oromocto,NB,Canada,E2V3N2 > > Tel-506-357-9785,Fax-506-357-6010 > > hartstv@xxxxxxxxxxx > > > > ***********************************************************************= > ****** > > Classifieds! Buy or Sell! > > http://sell.tech-assist.org > > The Tech Address Book: > > http://www.tech-assist.org/secure/tip/contact.htm > > Add a Repair Tip Here, or Change/Remove your Email Address: > > http://www.tech-assist.org/secure/tip/main.htm > > Lost Password: > > http://www.tech-assist.org and select "Lost your Login Info?". > > Email Archives: > > //www.freelists.org/archives/techassist/ > > **************************************************************************** * > Classifieds! Buy or Sell! > http://sell.tech-assist.org > The Tech Address Book: > http://www.tech-assist.org/secure/tip/contact.htm > Add a Repair Tip Here, or Change/Remove your Email Address: > http://www.tech-assist.org/secure/tip/main.htm > Lost Password: > http://www.tech-assist.org and select "Lost your Login Info?". > Email Archives: > //www.freelists.org/archives/techassist/ ***************************************************************************** Classifieds! Buy or Sell! http://sell.tech-assist.org The Tech Address Book: http://www.tech-assist.org/secure/tip/contact.htm Add a Repair Tip Here, or Change/Remove your Email Address: http://www.tech-assist.org/secure/tip/main.htm Lost Password: http://www.tech-assist.org and select "Lost your Login Info?". Email Archives: //www.freelists.org/archives/techassist/