Archive for November, 2008

Aircraft band receiver

Friday, November 21st, 2008

I’ve wanted to build one of these for years and never got around to it. Here are some links.

Gentoo – sys-libs/com_err blocking

Tuesday, November 18th, 2008

If you get errors about com_err blocking on your Gentoo system then you are probably experiencing a portage bug.

I was trying to install nfs-utils and received this error (shown in part):

[blocks B     ] <sys-fs/e2fsprogs-1.41 (is blocking sys-libs/e2fsprogs-libs-1.41.0)
[blocks B     ] sys-libs/ss (is blocking sys-libs/e2fsprogs-libs-1.41.0)
[blocks B     ] sys-libs/com_err (is blocking sys-libs/e2fsprogs-libs-1.41.0)

Some Google-ing led me to the following Gentoo bug and a solution. (See comment number 7)

Designing a better PCB

Tuesday, November 18th, 2008

A tutorial from SparkFun.

Viewsonic VP140 repair

Monday, November 10th, 2008

I received a Viewsonic VP140 LCD monitor for free, but it did not work. Pushing the power button resulted in nothing happening. About an hour of tinkering and tracing circuits led me to suspect two electrolytic capacitors on what I will call the switched 12V power circuit. There was a F7304 power mosfet IC that seemed to feed a 12V bus that powered the main part of the circuit. This IC was getting good power and seemed to want to turn on but there was only the briefest flicker of voltage turning on when pushing the power button. There are two caps on the downstream side of this IC, C24 and C110 (I think, need to take pictures for this posting). I unsoldered these two caps and was rewarded with a green power light when pushing the power button. I replaced the two caps, buttoned back up and now have a functioning LCD monitor.

For anyone with a similar monitor be aware that there are several different PCB styles for this monitor. Mine is the 300 series (need picture of PCB here).