Don Logic would be that Q801 is open. What about Q903 which is connected to Q801 B through R801. Q903 is called a switch and gets a signal form IC901 pin 18. Q903 C is to be at .02V. IC901 sends +5V power on to turn on Q801 and IC853 If Q903 C high try grounding the collector. Use 60 watt bulb in place of fuse to prevent blow-ups. Al G Al's TV-Electronics Pembroke Ont. Canada Don Hartigan wrote: > First let me thank Bob,Ty& Eric for sending me prints for the K51 > chassis's,however this model TXJ3678 is a slightly different 36" beast.It > came in DOA.The HOT=KSD5703 was shorted & ZD809=15 volt zener.I replaced > these & the unit will now pulse on/off.There is no 135vdc getting to the > collector of the HOT.This comes from the secondary of the SMPS,from > Q801=SFP9640.The 135 is on the base & collector but not the emmiter,which is > the actual B+[135] for the HOT.All the other 2ndary volts are ok & I a good > horz. dr. signal to the base of HOT.Tryed lifting the Vert o/p ic & the yoke > just incase they were loading down that line.A print of this model TXJ3678 > would be most helpful........TIA............ > Don of HARTS-TVCR"ASC" > 9 Robert St.,Oromocto,NB,Canada,E2V3N2 > Tel#506-357-9785,Fax#506-357-6010 > Email-hartstv@xxxxxxxxxxx > > ----------------------------------------------------------------------------- > Lost Password: > http://www.tech-assist.org and select "Login Problems?". > Email Archives: > //www.freelists.org/archives/techassist/ > ----------------------------------------------------------------------------- Lost Password: http://www.tech-assist.org and select "Login Problems?". Email Archives: //www.freelists.org/archives/techassist/