RCA BC5B Partial Rebuild Story

[emrr]

B1 high, suspect 4R1B low in value or insufficient current draw from PGM. Note 4R1A high and 4R1B low could be a combo leading to all these results.
everything else low, suspect R5A/B too high in value or too much draw in MON amp. Confirm 4R2.
B5/6 relations same as B7/8, so any comparative difference there is R value or current draw.

Be sure to give at least 5 minutes warmup before checking voltages, if that looks non-dangerous but off then give it a half hour and check again.

Filament high - if the ratio of input voltage to output voltage is off it can only mean stated current draw isn't being met. I would verify filament voltage at the sockets, not the PSU, there will be line losses from the wire.

 

[FPALB]

Well just like yall said - the further I went with tweaking the more things just sorta started to fit into place. Voltages all have come to reasonable values. I had bad buzz that some how was a bad power cap, which to my knowledge are all fresh. Unsure how that happened, but maybe some early stress I put on it killed it. Monitor out was completely unusable because of a bad 12ax7.

Wired the direct outs from the pre amp cards outputs and there is tons of gain on tap. Signal is nice as well, some low end and mid range loss, but nothing that couldn't be made up later if desired.

Cleaned up the outside, and put the main knobs through my ultrasonic cleaner for just a couple of minutes and its shining again.

Wired in the mains power switch finally.

Still need to label the I/O, and install the tube shields, but besides that it sounds and looks amazing!

Thank you all for your help. These are wonderful machines and I hope they keep on living.

 

[FPALB]

Tube shields installed and the unit is doing great!

Last snag I ran into was putting in too low of a 4R2 resistor in the power supply that feeds the plates of the power amp section. The resistor was starting to look a little burnt and thats when I realized it was much too low rated. Replaced it with a big 25 watt resistor and its great now.

The console is off to its new home tomorrow.

Thank you everyone for your insights and help through out this rebuild. All the best.