[mythtv-users] FE/BE combo system locking-up

Stephen Worthington stephen_agent at jsw.gen.nz
Thu Dec 16 05:24:21 UTC 2021

On Thu, 16 Dec 2021 12:49:42 +0800, you wrote:

>> On 16 Dec 2021, at 12:23 pm, Stephen Worthington <stephen_agent at jsw.gen.nz> wrote:
>> On Wed, 15 Dec 2021 12:30:43 -0700, you wrote:
>>> On 12/14/21 1:34 AM, Stephen Worthington wrote:
>>>> This one - dust certainly can cause this, and if you are not at least
>>>> annually getting rid of it, it will cause problems.
>> -
>> "Vacuumed" - do you really use an ordinary household vacuum for
>> cleaning electronics?  That is a really bad idea!  Most vacuums create
>> huge static electrical charges - they are actively dangerous to
>> electronics.  There are special non-static electronics safe vacuums
>> that you can buy, usually from commercial electronic component
>> suppliers.  But they are massively expensive.
>> The voltage
>> differential to the silicon in the chip causes movement of atoms and
>> molecules and changes the characteristics of the junctions in the
>> chip.  Immediate failure can result, but it is more normal to get
>> degradation that fails later in life.  And if the nozzle came close
>> enough so there was an actual static discharge, even more damage is
>> likely.
>When I worked for HP they did a big survery of static on various chips including ‘harmless’ chips like TTL.
>They found it had a significant effect on lifetime, So eg a harmless TTL chip exposed had a statisticaly significantly life time effect.
>Bottom line in 1: Static WILL damage your electronics.

My first job was with a company that made electronics products on
premises (design and build).  This was before flow soldering -
everything was hand assembled and hand soldered.  The failure rate of
products on testing at the end of the production line was horrible -
nearly 20%!  Shortly after I arrived, the engineering staff were
called to a meeting in the factory where we had our first lessons on
static safety from a 3M salesperson.  This included a film that showed
graphic micrography of junctions before and after deliberate static
damage.  And a few weeks later after the factory (and us) had received
our antistatic equipment and had started using it, the failure rate at
the end of the production line dropped dramatically to about 5%.  With
more care and training over the next year, and requiring that our
suppliers were doing antistatic handling, that came down further to

In engineering, we had always had a problem with our prototypes
mysteriously failing just when we wanted to use them.  So we typically
built 4 or 5 prototype units so that we would always have 1 or 2 that
were working while the others were being repaired (or altered where we
needed to redesign them a bit).  Once we started doing proper
antistatic procedures, we found we only needed to build 2-3
prototypes, because they mostly kept working unless we accidentally
damaged them.

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