Archives April 15, 2007

Sunday 15th April 2007 - 19:21:13

Chip

Today I went to Josh's new house to install a LAN. We managed to get all the cable pulls done but unfortunately it was getting late so I had to go before I finished. The cables for the "Cyber Den" are all pulled though the floor and ready to take sockets though. The patch panel is also neatly finised. I also ran out of time with the phone as there was a dodgy connection in the phone line where the outcoming cable was not following standard. Unfortunately I didn't have time to pull apart the connection and inspect it. The connection is a nasty one by the looks of it. Three cables coming into a bundle of twisted-and-taped type joins. No solder it seems. I will see though apon further insepction.

Saturday 14th April 2007 - 19:20:12

Chip
Much vegetation. Not much news.

Friday 13th April 2007 - 19:18:47

Chip

It's now burned permanently into my brain!

Pull R9, R10, R11. Break the trace from pin 6 to the +10V rail. Repace R10 with a 3.3KR 1/4W Carbon Film Resistor. Replace R11 with a 33 microfarad 35 volt electrolytic capacitor with negative facing the SCR. Turn the board over. Scrape the broken pin 6 trace on the pin 6 side. Solder a 15V Zener Diode from pin6 trace to ground. Solder a 1n4148 signal diode from pin3 to pin 6. Add a 680p ceramic cap in parallel with C2 on the back of the board. Run a 330K 1/4W Metal Film Resistor in heatshrink from pin 6 to active after the fuse.
Fit the power cord, socket and mounting block. done.

I modified 16 boards in this way - it doesn't seem like it'd take so long. It took me a little over 8 hours. It is delicate work though and must be done accurately or the board will toast it's self. Something different. I did enjoy it - even though I was stuffed after 8 hours of soldering and assembly =)