On Sun, 3 May 2020 at 22:17:51, R.Wieser wrote:
John,

Probably not a bad idea - if they aren't already - to label the leads on
the old case, assuming you're not scrapping it.

That isn't a bad idea. Even though the reason I'm intending to take the
motherboard out is that I'm a bit vain, and the other case simply looks
better than the contemporary plastic-looking "Scaleo 600" one. In other
words, although the case is fully functional I'm probably not going to
re-use it. but, never say never.

Well, even if you give it away.

The speaker plug is nearly always - always IME - a 4 by 1 connector,

Yup, thats what I remember too. Using a piezo tweeter to test (next to no
current) will show quickly enough where the connector needs to go.

Hmm. You'd have to have the mobo on and continually beeping; and I
wouldn't feel too happy poking round a live mobo with bare wires!

Sometimes they are two identical ports side-by-side. (USB2 is only four
pins.)

Thats them. Though in a 2x5 configuration, both aligned to the left. As
opposed to a later 2x4 configuration with one row of connections going from
left-to-right and the other from right-to-left (iow, both orientations
work).

Hmm. One side might, but I think not the other: you'd end up with +5 and
0 reversed, and I think the data lines too.

Small ones, I'd guess might be for case fans, or audio in/out, as you say,
depending on location.

Yep, also got that feeling. One might even be a WOL input one (connected
to a/the network card).

Right, hadn't thought of that - not something I know much about; I'd
vaguely assumed it didn't need extra connections.

I don't know if there is any standard for case LED/switch wires!

I don't think so, but that way I can either, if needed, plug the connectors
back in the right way, or allow me to grab the wire and follow it back to
the front panel to see whats connected to it. Though the "scribblings" are
a good indication to their functions.

Yes, there's usually a series resistor, so shouldn't _damage_ them the
wrong way round.

? I thought that LEDs do not get damaged by putting them the wrong way
around. At least not when they are supposed to work when connected
correctly. They just behave like actual diodes and block the current. Or

Yes, silly me. Although I think they tend to have a lower max. reverse
voltage than even the weediest signal diode, but it's still more than
their operating voltage. (Otherwise those back-to-back ones where two
colours are in the same package wouldn't be safe to themselves.)

has that changed since the old red ones ?

As a side shoot: I believe a red LED is actually a much better voltage
reference than a Zener of that sort of voltage rating: LV Zeners have
rather "soft" curves, whereas a red LED drops about 1.8 volts pretty
precisely over quite a broad range.

Regards,
Rudy Wieser


John
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

"In the _car_-park? What are you doing there?" "Parking cars, what else does one
do in a car-park?" (First series, fit the fifth.)