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Old 01-05-2018, 02:56 PM
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bandersen bandersen is offline
RCA 741PCS
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 8,103
I was tweaking the horizontal drive trimmer cap to get rid of that annoying line when the image started to fade. I smelled something burning too and turned the set off immediately. I sniffed and poked around and it seemed like one old paper cap near the HOT was warm. I powered it back up to troubleshoot and the drive signal on the HOT grid was fine, but 0 HV.

Time to examine the flyback. I grabbed a DMM and found intermittent HV winding readings. Sometimes infinite. Sometimes fluctuating in the k and M ohm range.

Let's take a closer look.


Ugh. Found a 14 A fuse in the 0.25A holder


Poked around and would briefly get the correct resistance on the HV winding giving me hop it's not fried. The fine wired had some green corrosiion so I unsoldered the end and slide off the spaghetti tubing.

After a couple flexes, the wire broke off. I cleaned it off near the wax and tacked in a temporary bridge.

That restored solid continuity. I'm going to clean out all the dust, replace the fuse and splice in a proper repair. Then fuly recap the horizontl circuit before another power up.

Worst case, I think I can dig up a replacement flyback.
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Last edited by bandersen; 01-05-2018 at 03:00 PM.
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