RCA 621ts Restoration

[vts1134]

Originally Posted by vts1134

Fired the set up for the first time and got a surprise. C128B (one of the main filter caps) blew up in a cloud of foul smelling smoke.
**THIS IS IMPORTANT TO ANY ONE WHO WILL READ THIS AND START A RESTORATION OF THEIR OWN**
The Rider schematic has a misprint. It incorrectly switches the placement of C128A and C128B.

Why is this important? Because C128B is rated at 150v not 450v and I'd like to save you the look your wife will give you when you smell up the house.
After replacing the offending capacitor I fired the set up again. No explosions , however I didn't hear the horizontal oscillator so I investigated in that area. After swapping the 6SN7 out (it was one of the few non RCA branded NOS tubes) with another tube in the set I got the characteristic sound of the oscillator.
I took some voltage measurements and every thing was in the neighborhood so I installed the crt fired the set up and was greeted with.

No video or sound just yet but it seems like a good time to quite for the evening.

I think the more important lesson to take is that I was frustrated and worked in a hurried manor that caused me to make a mistake. Learn from my bone headedness and when you get turn the lights off and return when you're .