Saturday, January 28, 2012

Fix It!

CD Player   (02FEB2014)
No "show", only "tell".
It's a Sony CDP-190.  I bought it new, '90, '91.
It started skipping or something, irregularly, several years ago, and I tried a Cleaner CD and thought that got it.  Recently, it got really bad, about 20-30 minutes into a CD.  Figured this was <b>it</b>, time to take the cover off.  Not a lot in there, it's from the Component Era, mostly empty cabinet, but parts of the CD mechanism were open for examination.
There's a guide rod, stainless steel, that the laser travels on.  The laser's mount has gear teeth on one side that mesh with a gear that spins, so that's how the linear motion (no lead screw with this) gets done.
Anyway, that stuff is all nylon, not built for the ages really.
I put a drop of "precision lube" on that guide rod and ran the laser to the extremes back and forth several times, figuring maybe it was binding up on that a little.
So, I'll see how that goes. (Only time will tell.)
06JUL2014 - It got better, but there's still trouble. I wonder whether it may be sensitive to bass/vibration.


TV Power
A few years ago I bought an LCD TV and I didn't like its picture much after I got it home.  It's been serving as a marginal computer monitor.  It had been working trouble-free till it started having a problem "turning over" from a cold-start where the default screen would come up, left-half dimmed, and then pop up and go back out.  It wasn't getting good spark.  I'd have to go a few cycles of the on/off.  It got to the point where that exercise was fruitless.

It was powered by an external mini-brick, a 12V, 4A switcher.  Its little green LED had begun this odd flickerating.  A-ha, bad power supply.

About the same time that I bought the TV I'd also grabbed a nice surplus MeanWell switching supply from bgmicro.com - 15V, 10A.  I was using to test a high-power motor.  With its adjust pot, I turned it down to 12V, no problem.  I cut the output cable off of the bricked mini-brick, stripped the cut end and crimped some forks on.  Taking a deep breath, I switched on the AC to bring up the supply, and clicked the TV's on/off: Bingo.

I ran it out of box for a week or so and then committed to placing all in a proper enclosure and so on - with panel-mounted IEC filter/inlet and power switch (both of which I pulled out of "treasure".)

It was a matter of laying out tape, measuring and marking perimeters, drilling, nibbling, and filing.  The MeanWell's mounting studs were drilled for M4.  I think an M4 screw goes in a 4-40 tap OK, but a 4-40 screw in an M4 tap doesn't work.  Lucky, I had four M4s from something I'd scrapped out.  Some crimping and wire-nuts and it looks pretty good and works great.
The switch has nibs for small-pattern quick-ons, which I had none of, so I soldered to those terminals.  I like it because it's a big push-button, approx 1_in sqr, and it has an integral neon lamp.
[A week later, I was looking in the drawers at RadioShack and they have the small-pattern quick-ons.]