[Mageia-discuss] UEFI and Secure Boot

[andre999]

Morgan Leijström a écrit :
> onsdagen den 22 augusti 2012 21.43.07 skrev  Rene Rasmussen:
>>   On Wed, 22 Aug 2012 19:51:31 +0100, Maurice Batey wrote:
>>> On Wed, 22 Aug 2012 18:35:09 +0100, Anne Wilson wrote:
>>>> To be honest, I'm not competent to start replacing chips on
>>>> a RAM board, either.
>>>>
>>>    It's a bit scary the first time, but if you follow one of the
>>>
>>> really helpful video clips out there on the 'net, it's not a big
>>> deal.
>>>
>>>    The main importance (apart from using the correct chip!) is to keep
>>> your fingers from direct contact with the chip, to avoid any static
>>> charge jumping across.
>
> To this point i do not fully agree; Metal tools give much stronger discharge
> than fingers. But a reason to avoid toucing is to avoid contaminating around
> pins with sweat (salt, acid), fat and other dirt.
>
> I have conductive plastic pliers for component handling, but they do not have
> such firm grip as metal pliers.
>
> Then there are more expensive metalpliers with conductive plastic handles
>
> (conductive in this case means very very sightlyu conductive not measureabla
> using standard multimeter, as it should avoid hard discharge, - just slowly
> bleed away the charge)
>
> None of the options described is as important as avoiding charges to build up.
>
> In my workshop (i build electronics prototypes) i avoid clothes of synthetic
> fabric, wear conductive slippers - if any, have conductive carpet, and
> conductive mat on the relevant tables.  But those are expensive is sold as
> such.  I have measured some cheaper rubber mats are good too.
>
> The less expensive approach is to use a wristband.
> A plus is to avoid sunthetic clothing, and you could work on such pink bubble
> palstic wrapping some electronics come with, it is antistatic.  Avoid metal
> and plastic table, prefer untreated wood.
>
>>
>>   Or set up an anti-static workplace. That would be the correct thing to
>>   do.
>>   Static discharges are probably responsible for 90% of all electronics
>>   going bad.
>
> (not counting design errors. My favourite complaint is that designers put
> eletrolytics unecerrarily close to hot components - the most common repair we
> do is to replace such.)
>
> ESD damages are not always immediately noticeable, but often age the component
> so it have less life left (simply speaking)
>
>>   I never touch any of my computer or electronics parts without my ESD
>>   wristband securely connected to my workspace.
>>   (having worked with electronics professionally for most of my life has
>>   taught me that!)

Sounds like good advice for 20 or 30 years ago, before chips normally had 
tristate buffers and a common floor covering was those polyestre carpets which 
were so good for rubbing your feet on so you could give an unsuspecting victim 
a shock by touching them.
Chip technology has advanced enormously.  Much circuitry is wave-soldered to 
the process board, thus even more immune to static discharge and dirt.
And those cheap static-producing carpets are a lot rarer.
Single chips with delicate pins are also a lot rarer.
Static charge is more likely to disrupt a functioning system, rather than cause 
any physical damage.

I'd say the biggest risk to electronics today is damaging a process board by 
flexing it too much.
I'd prefer a soft cardboard surface to anything else.  (Protects both the 
surface beneath and the electronics, and doesn't create a static charge.)

>>
>>   regards,
>>   Rene
>>

-- 
André