Problems with 1954(5) Philips R-7520 - Videokarma.org TV - Video

SkyLlama · #1 07-09-2013, 03:55 AM

Hey All,

I've been working on this set the past few days and when I woke up this morning I went at it again. So far It's been recapped a few resistors replaced, cleaned, tubes tested and I've worked out an annoying issue that stopped it producing HV.

This morning I looked it all over and decided I was happy enough to start it up with the CRT in place and see how things went. At first it looked fine, sound came up and the CRT slowly started coming to life and everything seemed fine.

About 2 or 3 minutes into the run things went bad fast just as I was going to power down the set and do some more work on it. The 6W4GT damper started arcing and about 2 seconds later smoke from somewhere with the fuse blowing immediately (which I hope stopped any serious damage)

I've checked everything and can't find any errors in my work. I also can't find where the smoke came from. If it was a cap I'd know because of the smell and obvious signs, but this largely had no smell and dispersed too fast for me to see it's origin.

Nothing visually looks bad, but I'm going to go and recheck absolutely everything. I'm assuming for some reason one of the voltages ended up way way to high, but I don't know.

I'm on a mission to get this TV fixed, this is really only a minor delay, but a frustrating setback when I was so close.

I'm wondering if you folks have any ideas what happened. In all my fixing tube based stuff I've never once seen a tube arc.

I relatively new to this so I don't have a lot of the test equipment, but I've been borrowing stuff from our local retired TV guy

SkyLlama · #2 07-10-2013, 02:18 PM

To anyone reading this, I've figured out what happened after going over everything. Nothing serious and I fixed that issue.

Have to get a few more parts and maybe a new damper tube as I think it died during the event.

Should be working went I get the bits I need. Will post again later when I've got it all done.

Jon A. · #3 07-10-2013, 02:39 PM

I for one am clueless as to what may have happened, but I'm interested in knowing what went wrong and seeing that rig running properly. It's interesting to see another novice going at this.