Why it’s important to have oscilloscope and not always rely on multimeter measurement.

Here I post couple pictures of me, fixing LED WALL CLOCK.

There are spikes caused by (DC-DC converter) capacitor that failed (open, lost capacitance, high ESR) and they lead to RTC / MCU freeze and cause undesired operation.

On pictures there is waveform with failed capacitor (notice spikes) and after replacement.

Video:

Good looking capacitor turn’s BAD – why it’s good to have ESR meter

Here i’m working on Dymo PSU that failed, i most like expect leaked capacitor – but everything looks fine… for my eye… but not for ESR meter… we find a open (dead) cap that looks perfectly good and would never expect me to believe it was cause problem!

Also here is my video

How RIP VideoCD disc on linux and play it back on device without cdrom

I have lot of movies on VideoCD that i bought just to have in my collection and are still fun to watch, but DVD drive on my laptop computer many years ago was switched to second HDD caddy. Only way to play them is using external USB DVD drive with is problematic to carry around:) Is there option to easy “RIP” copy VideoCD disc into video file for easy playback?

Yes… on Ubuntu and many other distributions is easy as one command.

vcdxrip -C=/dev/sr0

where /dev/sr0 is our drive, in my case external USB drive
after running that command, we get extracted all .avi files that can be played from HDD using for example VLC player.

3d printer – real case of use on Dell Optiplex 760

Recently i got Dell Optiplex 760 as computer for driving my 3d printer and web browsing while working on my projects.

This is very good computer dedicated for office use, many things could be replaced without use any tools, just by pulling right lever You can for example extract 3.5″ HDD drive without need of using screwdriver, same thing goes to DVD-ROM.

There is also a FDD drive, with today i call obsolete (i still have couple 3.5″ floppy drives around but with USB port, in case i need read – write FDD i can) but having it hard mount on computer it’s not necessary.

I want mount old SSD drive, 2.5″ in place of floppy disc drive, but because it was using latches and special bracket i will left in option throwing it inside without securing in place…. but? i found answer… we have 3d printer.

Before designing anything myself i always check Thingverse to make sure i won’t reinvent wheel second time… and… i get everything i need!
Special adapter that convert 2.5″ SSD for caddy that will swap in place of FDD and also COVER in exactly right size to fill hole after FDD.
I send picture to friend, and he realize that i 3d printed it after i told him to look for it.

Here are pictures of ready print before and after install:

Here You can download STL files for print:

CADDY:

https://www.thingiverse.com/thing:3229517

FDD cover:

https://www.thingiverse.com/thing:3229510

Zello sounding like DMR Motorola aka Talk Permit Tone

Here are two files that make Zello sound more like proper 2 way radio. ( Motorola Mototrbo )

One file is for beginning second for end transmission

Installing Mac OSX from USB on Power MAC G5

My DVD drive was broken on old Power MAC G5.

Im not interested in finding replacement because it’s anyway obsolete but i need to install Mac OSX.

Lucky G5 have Open Firmware that allow booting up straight from USB flash drive and take install painlessly!

First You need to create RAW image of  Your Mac OSX DVD into file.

Than using for example DD on linux put it straight to USB flash-drive.

There many tutorials about that topic.

 

I have Microsoft keyboard while starting up Your mac press and hold four keys at once:

Windows key + alt + o + f

until You get a gray screen with letters “Welcome to Open Firmware” and command prompt.

type

boot ud:3,\\:tbxi

and press enter

after while You will get standard installer just like on DVD.

ud:3 is device id, to not confuse Yourself remove all USB storage devices except that one You want boot from.

 

Here is mine video in real live:

Clansman PRC-350 (RT350) battery adapter mod for use rechargeable AA

Before and after applying mod

 

Leaked capacitor strike again! – devastation of power supply by electrolyte

Another failed power supply caused by leaked AC capacitor… this time PSU covered with electrolyte…