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Philco Predicta board lifted trace and trace corrosion.
#5

Hi Jas,

One of my more favorite solder suckers used to be available from Radio Shack. Was an Iron that instead of the usual tip, had a nozzle, stem and bulb. It worked well. One should be careful of overheating, but IMHO, it worked better than the various de-solering tools(Solderwick, Soldavac (Manual spring loaded syringe that the user cocks, puts against hot joint and pulls trigger), etc. Best is a pro de-soldering station, but these cost lotza bux. A metal brush may take care of the corrosion. Re-tin the trace.

Judging from the pix, there are a lot of cold solder joints on that socket. Why are you replacing the socket? Is there obvious damage? If the issue is intermittent operation, check the condition of all solder joints on the socket. The picture seems to show cracks in several of the solder joints that would break the connection.

On old boards, I will run some 18 gauge solid insulated wire over the trace from point to point, following and paralleling the trace. For example, from the heater pin to the next heater pin, transformer lead, ground, etc., particularly for the heater, cathode and plate connections that handle large current. The horizontal output tube may draw more current than any other circuit in this TV.

It is also common on TVs of this vintage, where the PC Board mounts on tabs bent up from the chassis, that the solder connections between these boards and the chassis are also poor. if this tab is providing chassis ground to the board, failure of the solder joint will cause all sorts of problems. There is often more than one of these chassis grounds on the same board, and often, they are not connected to each other. Therefore all of these joints must be good. It is a good idea to consider point to point wire connections for these grounds also.

I have fixed many a TV and other electronic device by reheating cold joints, adding point to point connections, etc.

Hope this helps.

John "MrFixr"

"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
Best Regards, 

MrFixr55


Messages In This Thread
RE: Philco Predicta board lifted trace and trace corrosion. - by MrFixr55 - 04-08-2022, 03:29 PM



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