FPGA as heater

On Saturday, 4/15/2017 1:15 PM, John Robertson wrote:

> 
> As an example - Common/Ground designs in early arcade games were not 
> always at their best. A number of early electronic pinball games used to 
> burn up driver transistors and coils at random until I traced the 
> problem - which was  a design error where all the commons (MPU, Audio, 
> Solenoids, Lamps) came together at the regulator board through several 
> different pins, and as each pin connection oxidized slightly it allowed 
> ground potential differences between the MPU and the solenoid logic 
> grounds, leading to the transistors being slightly biased on...
> And this game logic had been designed by Rockwell.
> 
> John

This sort of poor design is common in consumer electronics.  Likely
the engineer wanted more or better ground connections, but got shot
down due to increased cost of connectors with either more pins or
better plating (silver or gold).  As long as the oxidation issue
happens _after_ the warranty period expires, there's no incentive
to correct the design, either.

-- 
Gabor