1958 RCA 14-PD8057 Horizontal Issues/Circuit Board Nightmares

[Chris K]

Hi folks. Working on one of these very popular B&W portables. I've restored and sold several but this latest project is giving me some fits to say the least. Anyone who has worked on one of these knows the circuit board was not designed with service in mind. It's mounted and shielded like a bank vault. The board itself is grounded in six places to the chassis frame it sits on...the 4 corners and for good measure, a spot in between on the 2 long sides. Additionally, there's an RF shield about half an inch under the board covering the entire thing that's screwed to the mounting frame and has almost inaccessible tabs soldered to points on the traces of the circuit board in 4-5 places. There are some access openings but they are not solder iron friendly for sure. Removal of the CB is not a practical thing to do given it's situation and the soldering and presence of many wires on the top of the board. For this reason, most of the work I do on these TVs is top of the CB component replacement. The power supply is so much easier to service.

So given this, the TV has a NOS 14ATP4 CRT that's bright and crisp. It has issues with a jumpy and distorted horizontal circuit so I was attempting to adjust it by turning the core in the horizontal waveform coil mounted to the dreaded CB. Just as I was getting close, the core crumbled. I was able to get a NOS Miller 6337-R direct replacement for it. I think I'm just going to clip off the broken coil and solder the new one in by attaching it to the metal tab remnants on top of the board instead of diving into hell on the underside.

Stay tuned. I'm all but certain I'll create more issues than I solve!