Serviceability, Corvettes, and the HP/Agilent 3577A network analyzer

I gave my buddy Paul Grohe an HP 3577A network analyzer that worked OK except that the cursor knob did not work. All my pals had theories, maybe the glass scale was broken, or the processor board was shot. My deal with Paul was that if he took it, he had to fix it, or at least try. The results are up on a new slideshow here. Turns out that the analyzer uses a light bulb to illuminate the encoder wheel. All Paul had to do was get to it, which was pretty tough, and replace the bulb. One day he will figure out an LED you can cobble in. This encoder is used on a lot of old HP/Agilent test equipment so this may help a lot of you get the cursor knob working. Paul said the fix was no big deal but I felt there was a lot of specialized work to get to the encoder. Check it out for yourselves.

This lack of serviceability is not confined to test equipment. It reminded me of a buddy that quit his job as a General Motors engineer back in the early 1980s over a similar lack of serviceability. He worked a the AC Champion instrument cluster division.. They were getting ready to go into production with the 1984 Corvette. Since the dash illumination bulbs were shrouded and ran very hot, the engineers calculated that the lifetime of the bulbs would be about 500 hours. This is pretty bad, but what made my friend get disgusted enough to quit was the serviceability of the bulbs. In order to replace them the instrument panel had to be removed. This meant dropping the BCPS (Brake and Clutch Pedal Support) as well as the steering column. The estimated cost was $1800. It may be an engineering oversight to have a short bulb life. But is it pure corporate evil to have MBAs and stylists and clay-carvers so dominate the company that it takes 2 grand to change a bulb in the dashboard.