Importance of a clean chassis

[Charlie]

A couple of months ago, my mid-80's CM 19" color set started having a problem. The green would go away for a few seconds and then come back. It started getting worse... happening more often and for longer periods of time. Eventually, it got to where the green was missing most of the time.

I took it apart and tried spraying some cleaner on the screen control and worked it back and forth. While in there, I took a small brush and vacuum to the boards and and put it back together. Worked like a champ... for a couple of days. THen it started all over again... a little at first and got worse as the days passed.

Went back in... this time resoldering some connections in case of cracks in the old solder. Also worked all the wire connections. Put it together and worked again... and again just for a couple of days. Damn!

Third time turned out to be the charm. This time, I looked at the boards a little closer. Still could see some dust around caps and resistors. I didn't have any cans of air, so instead I grabbed a can of cleaner without oil and sprayed the main board down. Cleaned it up pretty good and put it back together.

Again, it worked. But this time, it's been 3 weeks, and so far I haven't seen the green tweak out at all. It's been perfect.

Even better, something else got fixed. For years, it had some squiggles at the bottom of the screen. If there's any vertical lines in the picture, you can see where they get out of whack in the bottom inch of the picture. Not bad, but just enough to notice them. Any fine print at the bottom during commercials is usually difficult to read. I always figured it was due to some anomaly in the yoke or flyback. Come to find out, after spraying down that board, those little squiggles went completely away! Bottom of the picture is perfect.

I always clean out a set, but taking it a little further this time was what it needed. It's amazing what just a little bit of dust can do if it's in the right spot.

[ctc17]

I have found cleaning them causes mor problems than not. At this point I refuse to even blow them out. I can see where metallic dust may cause issues but not household dust.

I have a feeling you deal may be a fluke, sounds more like a cracked solder or intermittent issue in the CRT. I hope I'm wrong and your onto something.

[Einar72]

Working on cell phones, I have found any residue under certain components makes the difference between running or not. With our vintage friends, lifting one leg of a cap or resistor can uncover an amalgam of forgotten flux, cigarette smoke, dust/dander and kitchen grease after you thought you had the board clean, which acts like its own little current path... Hopefully the resistors have a hard, shiny case and can be wiped clean as well.

[zenith2134]

You're talking to a guy who takes this very seriously ... I routinely disassemble most sets and scrub down the board after touching up sketchy solder joints. 91% isopropyl on the foil side (with toothbrush)to de-flux the work.
Around the HV cage of even a modern crt, there always seems to be dust buildup. Blow that out with canned air ! It works a charm.

[Charlie]

Originally Posted by ctc17

I have found cleaning them causes mor problems than not. At this point I refuse to even blow them out.

I'm a bit surprised by this. I can certainly say I've never had a set that performed worse after cleaning out the dust.

I've had TV's or radios that simply would NOT play, and all it took to make them play was to get the dust out of there.

When I got into this hobby 20 years ago, cleaning out the dust was the first lesson I got, and was surprised at the before vs. after performace of the chassis being worked on.

I think Einar72 is right... I simply had a bunch of crap hiding under some caps and resistors. I just didn't get it all out during the first time I cleaned it.

[Kamakiri]

Ironically enough, I had to do the same thing recently to the ITT Mackay receiver that I got from you many many years ago . I finally built an MDF case for it over the summer, and I discovered that a tiny bit of sawdust had worked its way into the tuner.....

[Charlie]

I bet that old receiver had some vintage dust hiding under caps!! That was a cool old receiver with a really neat vintage digital display!

[Kamakiri]

I love it, which is why it's still in regular use

I had it gone over by a ham radio shop locally about half a dozen years ago when for some reason the audio was dead. Couple bad resistors and a general cleaning and alignment as memory serves. One look at those component boards and I knew that repairing it was WAY beyond my areas of expertise.

[Chad Hauris]

I have never had cleaning out a chassis with dry compressed air and a vacuum cleaner cause any problems...many sets I have worked on were completely covered with desert dust and dirt. Anything stored in a shed or barn which is not tightly enclosed will fill up with lots of dust and sand around here...especially in printed circuit board sets.

[sharejutt]

Would Pledge multi surface cleaner be safe to clean a PS3 with ?