Motorola 21CT2B restoration

[Electronic M]

Originally Posted by oldtvman

When I had my shop sometimes I used to compare factory service manuals with photofacts. Sometimes they were right on and other times there were errors in the Sams version. I guess sometimes you had to take it for what it's worth, keep in mind a lot of time there were service bulletins that came out after both versions were released, and those had some very good info on them

I've had Sam's errors mess me up good enough on other sets to double check other literature when available.
I double checked the Sam's video IF alignment against the Motorola manual on the ETF and the video alignment was the same....
Rant time: both Motorola and Sam's (who appear to have copied Motorolas proceedure only renaming the coils to match their numbering) say to pull the horizontal output and to properly load the B+ to connect a 2K ohm 100W(!) Resistor across the B+...so I soldered 4 NOS 50s ohmite 500 ohm power resistors (with rheostat sliders not connected due to paper insulator) in series and set those in a jar...10min in I noticed the paper was smoking profusely so I pulled the plug about 10 seconds later the rigid assemblage of resistors desoldered themselves and collapsed to the bottom of the jar I was keeping them in for safety... Since I had more of those resistors I ended up using 16 in series-parallel to increase the wattage and make a 2K ohm resistor that needs an hour to char the paper... I have to wonder what Motorola was thinking specifying a 100W dummy load resistor...I don't think I have ever seen a TV that used a 100W resistor and I can't imagine the average repair shop would just have one laying around.

The video IF response on the first 2 injection points was dead on, the 3rd I was able to get close.