Category Archives: Hackspace

It’s an ENTS Miracle

The second worst thing about this time of year is the static charges that build up due to the complete lack of humidity. The worst thing about this time of year for a geek is the hardware you kill because of those static charges.

I almost killed my netbook today. I’d just finished burning a CD with a USB attached external and when to close the burning app and *ZAP*. Hurt like all hell and the netbook immediately powered off. I unplugged the USB drive and fired up the netbook, all seemed OK. I’d zapped the thing in the past and it’d been just fine so I wasn’t too worried at first.

And then the back-light cut out just after I remarked that “I’m surprised I haven’t killed this thing yet”. 2 minutes later, the back-light comes on again. It cycles back and forth time and time again, each time the on period becoming shorter and the off period becoming longer.

Out of an amazing stroke of luck one of the other guys in the hackspace today not only had an Acer Aspire One 110 with him, but he also knew his way around an oscilloscope too. I pulled my netbook apart and we attached my LCD module to his Aspire One and let it ride for a while. It behaved perfectly. So we started thinking the issue wasn’t with the back-light but either the power provided by the motherboard or with the dimming signal sent to the display module. With Matt’s netbook still powering my display we spent some time noodling around with the oscilloscope and with the help of possibly the correct data-sheet for the LCD module we verified that the LED back-light was powered by +5V and the brightness is controlled by a +3.3V PWM signal. Once we determined what the cause of the problem was, either the +5V line cutting out or the +3.3V signal getting mangled we could route around the problem. If it was an LED power problem then I could borrow some +5V from the USB lines to the webcam. If the +3.3V PWM signal was borked I could just wire the +3.3V line that fed the LCD module to the brightness control line and deal with a permanently-100%-bright LCD. With all that determined we shut down Matt’s netbook and connected my LCD module to the internals of my netbook.

I fired it up and waited for it to fail. And waited…. and waited… and it hasn’t happened since. I put everything back together and it’s been behaving. All that planning and geekery and I don’t even get to claim to be responsible for the resurrection of this netbook. Apparently I have a self-healing netbook. It’s an ENTS miracle.