??? 01/17/07 19:03 Read: times |
#130986 - depending on application... Responding to: ???'s previous message |
Richard Erlacher said:
How do you determine whether they are acceptable? Of course this depends on the application. There is no universal answer as there are infinite potential modes of failure of each of the zillions of parts used in electronics today. I think it's quite appropriate for certain type of products to simply perform the smoke test, then configure (burn) and perform the "try to wiggle with all buttons" test. If it's a board with "$2500's-worth of other components", in 100s series, there might be a JTAG-enabled (read boundary scan enabled, I know it's not the same nowadays, unfortunately) part and you might have developed some sort of testing via the JTAG. You need to perform the smoke test first, anyway; but this might save some hassle with shorted buses and similar stuff. I'd not suppose such a bad part which would burn out other parts (except voltage regulators and alike, but that would be too bad if those would not be reliable enough, anyway - I'd thrash the supplier or manufacturer of such). All this might be completely inappropriate for your needs and application though. JW PS. I've written a memory test when a "sclerotic" batch of SRAMs slipped through production to the field, but I knew exactly the mode how they failed from the examined specimen so the test was specific. |