mattdavala
10-13-2007, 10:22 PM
Hi Everybody,
I had gotten a Setchell Carlson 17 inch P-63 BW TV off of craigslist. It acutally worked after I reformed the electrolytics, the others un recapped. I had it running about 5 to 6 hours every day for two weeks. Worked flawlessly. I know I was chancing it, having something short out. I lucked out. It died peacfully, having its vertical sweep shrink and die.
Well I had my SAMS schematic ready and all new electrolytics and orange drops. Man was I in for a real workout. I have had no electrical schooling at all. I was able to rewire the power supply to its correct "true" form and also correct a technicians change in the vertical output section.
The previous owner had the set worked on, naturally. The old tech split up the B+ and added in a filter choke in series. He/she also upped the capacity of C1 and C2 filters from 100MFD to 200MFD!! So 400MFD! I took the filter choke out and found out how C1 and C2 hooked up without it. They were replaced with correct 100mfd's each. I replaced the other filters without incident.
NOW came another confusing vertical output section. There was a .03 1600V "buffer" cap and resistor in series from the plate of the 6CM6 to a connection on the yoke. That wasn't there on the schematic! Also there was supposed to be a 47K resistor from the plate to the screen. Not there! Just that .03 cap and resistor. I went to radio shack and bought a 47K 1/2 watt resistor. It was great they had the exact value. I went home and took out that buffer cap combo and added in the correct 47K resistor from plate to screen.
After finishing replacing every waxed cap I tried the TV with the light bulb in series trick. Worked great except for the vertical section having this WAVY lineratiry issue. I tried a few electrolyitics that connect to the cathode of the vert out to no avail. So I looked back to my wiring. I had miss-connected the 225 Volt B+ to the plate of the vert output tube. It was getting power from the top of C2, a main filter cap. At that point the DC wasn't filtered enough. The 225 B+ point after C2 has another 120MFD and 40MFD cap filtering it. I switched the wires. Bingo.
It works wonderfully.
Thanks for reading!
Matt D.
I had gotten a Setchell Carlson 17 inch P-63 BW TV off of craigslist. It acutally worked after I reformed the electrolytics, the others un recapped. I had it running about 5 to 6 hours every day for two weeks. Worked flawlessly. I know I was chancing it, having something short out. I lucked out. It died peacfully, having its vertical sweep shrink and die.
Well I had my SAMS schematic ready and all new electrolytics and orange drops. Man was I in for a real workout. I have had no electrical schooling at all. I was able to rewire the power supply to its correct "true" form and also correct a technicians change in the vertical output section.
The previous owner had the set worked on, naturally. The old tech split up the B+ and added in a filter choke in series. He/she also upped the capacity of C1 and C2 filters from 100MFD to 200MFD!! So 400MFD! I took the filter choke out and found out how C1 and C2 hooked up without it. They were replaced with correct 100mfd's each. I replaced the other filters without incident.
NOW came another confusing vertical output section. There was a .03 1600V "buffer" cap and resistor in series from the plate of the 6CM6 to a connection on the yoke. That wasn't there on the schematic! Also there was supposed to be a 47K resistor from the plate to the screen. Not there! Just that .03 cap and resistor. I went to radio shack and bought a 47K 1/2 watt resistor. It was great they had the exact value. I went home and took out that buffer cap combo and added in the correct 47K resistor from plate to screen.
After finishing replacing every waxed cap I tried the TV with the light bulb in series trick. Worked great except for the vertical section having this WAVY lineratiry issue. I tried a few electrolyitics that connect to the cathode of the vert out to no avail. So I looked back to my wiring. I had miss-connected the 225 Volt B+ to the plate of the vert output tube. It was getting power from the top of C2, a main filter cap. At that point the DC wasn't filtered enough. The 225 B+ point after C2 has another 120MFD and 40MFD cap filtering it. I switched the wires. Bingo.
It works wonderfully.
Thanks for reading!
Matt D.