23 Jun
2010
23 Jun
'10
12:47 p.m.
On Wed, 23 Jun 2010, Tony Duell wrote:
Not really. The 5150 PSU warning was understandable based on the fact
that there's 400V DC inside, and that voltage could remain even after the
mains lead was removed. There is no similar hazard that I can think of in
a car instrument cluster (the user displays are a mixture of analogue
pointers, LEDs and LCDs).
And the workshop manual (official, not a 'home mechanic manual' is very
clear about not dismantling it, but it doesn't give any explanation.
I see...
The workshop manual for our car specifically says that the insturmnet
cluster must not be taken apart. It doesn't go into more details, but as
it contains the immobiliser microcontroller and the odometer, there may
well be security features (like it'll erase memory if you open it up).
It's a VAG-group car, does anyone have any ideas?
Is that the same warning as the 5150 power supply? If so, how long did THAT delay you?
Just until I could grab my tamperproof Torx bits :-)
Can you get a cheap one from a wrecking yard? Or get
the dealer service
manager to save a bad one for you if/when they have to replace one?
The former is possible, the latter is less likely (although I am already
known to be crazy by my local dealer, I ordered the workshop manual, all
11 binders of it, and I've bought some of the special service tools...)
A related question : Therre seem to be several
types of lead-free solder,
and manufacturers service manuals tell you to use a particular one (often
to be bought from that manufacturer). Which means (to avoid
contamination), I would need a dozen of more reels of solder and
soldering iron tips. And what do I do about stuff I can't get the service
manual for, or where said manual is a boardswapper guide. When it was all
laed/tin solder it was easy.
Is there a 'universal' lead-free solder that I can sensibly use to rework
anything modern?
But the 'universal' solder has lead in it :-) I would assume that for many years, they will be
coming out with new
compositions of the lead-free solder. Maybe SOMEDAY they will succeed in
coming up with one comparable to the stuff with lead in it.
Right now, they seem to still be trying to come up with one that is
marginally satisfactory.
Alas I feel that's the case...
It will take a LOT of practice before I could solder SMT with lead-free
solder. I should probably start that practicing, but there are higher
priority tasks in the queue.
I am not looking forward to having to repair our Sony LCD TV. You are
supposed to fix the signals PCB to component level, it's got at least on
BGA chip on it and several fine-pitch PQFPs. And lots of SMD discretes.
They specify a specail (lead free) solder to use too. And all the
documentation you get is a schematic, no waveforms or other tests. That
is going to be 'fun' for suitable values of fun..
-tony