Thursday, October 29, 2009

Five years of school and ten years of industry experience: Just jiggle the connector

A couple of weeks ago, my oven stopped working. It's one of those gas range/electric oven dealies, with a smaller second oven where the broiler drawer usually is (the main oven is used for broiling). The control panel stopped working, but the gas burners would still light (not just spew gas, they would light without a match, which takes electricity) and the lower oven -- which is controlled by a dial rather than the digital control panel -- worked fine.

A little bit of googling told me it was most likely what I already suspected: The electronics in the control panel were shot. It is supposedly not too difficult of a DIY job to replace it, but based on comparable parts I found online, it looked like the part itself would cost about $150.

I opened up the stove and googled for what I thought was the part number, but to no avail. So we called GE. They wanted to send somebody out, but of course it's $80 just to even have them look at it. We got an 800 number from GE where we could most likely order the part, but it was already past 5:00 so we had to wait until the next day. In abject discouragement, I put the panel back together, screwed it back in, plugged in the stove, and turned the breaker back on.

But wait, rewind -- I am a computer engineer by education, and while I am more of a software engineer by trade, I still do a lot of low-level work, sometimes on custom hardware. When I had the thing open, you better believe there's one thing I was certainly going to do: Check for loose or bent wires, look for obvious defects on the circuit board, and, most importantly, jiggle all of the connectors. I can't tell you how many $10,000 systems I have seen rendered unusable because of nothing but a loose cable.

Lo and behold, when I turned everything back on, it works fine. Hallelujah!


  1. So what you're telling me is to drop out of school because it's useless? I agree, at the end of my five years I'm going to be just as unemployable as I was going in. Stupid history.

  2. Oh no no no, college serves all sorts of important functions -- for instance, regardless of one's major, most universities offer extremely valuable lab work in the field of neurochemistry...

  3. Percussive maintenance! :)

  4. oh great, now I've got doritos crums all over my keyboard. Look what you made me do

  5. Seriously, the two most valuable lessons I gleaned from my electronics lab courses were a) cables and connectors constantly fail - check them first, and b) goddamn 60Hz noise again. College is useful for far more than that - you still need to learn to arrive at a conclusion starting with observations and an understanding of fundamentals and first principles. Hardware debugging is an art I've been very slowly acquiring - it's part experience, part analysis, and a big dollop of luck.

  6. Oh man, the 60Hz noise takes me back... In one of the electronics lab classes I did, the centerpiece of the class was building an op-amp from scratch, and then the rest of the class was using the op-amp in you had built in various ways. We were like half-way through the op-amp-building part of the class, and every group of students were finding that they were having intermittent noise problems. Like, BIG noise problems. Like, everything would look fine, good SNR, etc., and then the oscilloscope would just look like static.

    Came to find out that construction was being done down the hall, and every time the workers used a particular tool (I believe it was a big-ass electric drill) the 110VAC would go nuts down the whole hallway. heh... they had to give us an extra week to finish the lab :D