On Thu, 7/24/2025 11:22 AM, Andrew wrote:
Every so often my main PC throws a wobbly and the screen freezes
with a distortion that I have come to recognize (and the HD activity
light stays off).
The solution has always been to remove the SATA plugs at each end
and blow out any dust, then reinsert and wiggle them to make better
contact, but they don't seem to have that feeling of proper
insertion that used to be the case with those flat parallel cables
and sockets that were the norm in IDE days.
Is it because the SATA cable connections between M/B and HD seem
to develop some sort of corrosion?.
Usually this happens when the room has got colder than usual but
it happened again today (and gave some warnings back when it
was hotter - *) and I ended up using one sheet of toilet tissue soaked
in methylated spirits carefully pushed into the connector with the
blade of a small Victorinox and wiped around to give the contacts
a good clean
PC then powered up and is happy again.
Are there better quality SATA cables available for commercial use,
and if so who would sell them ?.
(*) I don't even use my PC during a heatwave because the room is
hovering around 25C anyway.
Would an aerosol can of switchclean (or similar) help to clean
these plugs and their sockets out ?.
Has anyone else experienced tech failures during the hot weather ?.
For computer electricals, we try not to mix metal. Gold goes
with gold (glides). Tin goes with tin (bites).
The SATA connectors on the motherboard are gold plated 10u
(telecom plating is 50u). This means when we buy SATA cables
(red or black ones, all 6Gbit capable), the connectors on those
are also gold. Gold is a precious metal. 10u is thin enough,
there can be "pin holes" in the finish, but this does not necessarily
mean ruination. It should still work.
There are two retainers on SATA. The original retainer method
is "compression". The body of the connector is shaped, when molded,
such that it "presses on" its mate. This helps prevent it from
walking out, thermally.
A second method was added as an afterthought. SATA cables have a
"jaw" and a release surface you press on to stop the "jaw" from
biting its mate. Unfortunately, on WD hard drives, the "jaw" has
no where to bite, as WD drives, the WD Corporation invented their
own flavour of SATA connector, and it is an interference fit which
is not the same as the rest of the industry, The cable with "jaws"
on both ends, it bites the motherboard (and holds well), but if
there is a WD brand hard drive, only the "compression" feature holds
the cable. It still works, but is annoying (it "feels wrong" while
you work on it).
The signaling on SATA, is high speed low amplitude differential,
where D+ and D- are carried on two coax cables. The dielectric
might be polystyrene. When the cable comes out of the cable machine, it
was straight at one time. The coax conductors, the plastic insulation
was a constant diameter. The impedances matched.
At the motherboard factory, idiots take elastic band, and they fold
up the SATA cable below its allowed bend radius. If you "kink" a
SATA cable, it pinches the polystyrene-like material and changes
the dielectric impedance effect. The two signals now don't go through
identical environments. At the receiving end (after some loss through
the cable), there is a measurable BER (bit error rate) due to the
imperfect transmission environment. There is a counter in SMART on
the disk drive, and it counts transmission errors and the counter
does not reset. You can check the counter, and for any reasonable
computer install, the count could quite well be zero. But a damaged
cable could leave a permanent count of billions of errors, until the
SATA cable is swapped out. You record the current value on the
error counter, record the value tomorrow, take the difference, to
determine whether any errors accumulated that day.
There are error counters at both ends of the cable, for the signals
in either direction (7 contacts, three GND, two pairs of
signals, one pair for transmit, one pair for receive). The SMART interface makes it easy for users to find the error count in one direction.
I'm not sure where the motherboard count is logged.
*******
Nobody pays attention to the *power* on hard drives!
The ideal case on computers, is two looms with 15 pin SATA power
come out of the PSU. The user carefully runs this power cable
past the drives. (One loom maybe, for the optical drive, the other
loom for a couple hard drives). Because the cable comes right from the PSU,
the voltage for the motor is an ideal 12.0VDC with little loss.
Older drives get in trouble, if the received supply voltage is
11V. This causes the drive to "reset" itself, and if there is
"Hot Plug" enabled in the BIOS, the OS may recognize the drive
when it "comes back".
1TB boot HDD (WD Blue maybe) resets at 11.0V
24TB Helium Data drive resets at 11.5V <=== mine started a reset loop when brand new!
If you use around four power extension cables during your build,
and the HDD is on the end of this chain of connectors, the voltage
can be low enough to be around 11.0V .
So far I described an ideal situation, where with Hot Plug enabled,
the OS recovers after a short outage.
But another kind of failure on low voltage, is the CPU on the HDD
controller board "crashes". Not even a warm PC reboot recovers the HDD.
This is because, while the IDE ribbon drives have a very nice RESET
signal on the cable, there is no RESET on the seven connection SATA
data cable. You have to power cycle the PC, to get the HDD CPU to
reboot itself.
*******
Summary: While you could have a badly kinked data cable, it's just as
likely your power cabling needs sorting so that the drive
remains sane and properly powered.
The jaw equipped cables, the one disadvantage, is on an
Asrock first gen SATA board, you can pull the SATA motherboard
data connector right out of the motherboard, with a jaw cable :-)
a lot of later designs are swaged and the connector cannot
leave (ripped solder connections) quite as easily.
SATA cable ends come in straight, left-angle, right-angle.
On home computers, usually you buy a straight on one end,
angled on the other. I have a few cables which are left-angle,
and the cable tail points upwards when it is plugged into a
right-side-up HDD. Most of the motherboard box cables are
right-angle, and they point downwards when the angled bit is
used on the HDD end. The motherboard end may be good enough
that the straight end will work on that side. Think carefully
about what kind of cable you want -- the staff at the shop will
point out "the cable everybody buys", as well as cables that
might be needed for best fit on obscure Dells (the upside-down
one would work there).
On my Test Machine, the cables have well surpassed their
service life spec. I plug them in. They still work. The
retention isn't great, but, I'm not complaining. There is no
particular reason to be suspicious of them. As long as the
data cable is not pinch-kinked, the power chain is not too long,
both HDD and SSD SATA III, they both work fine.
For a 24TB Helium drive, do not use a five wire power cable. Only
use a four wire cable. You can extend the PSU loom with a
Molex to SATA six inch extender for example, which uses four wires.
The reason for this requirement, is the 3.3V rail wire, if left
connected, it tells the Helium drive to "not spin up". Your brand new
24TB drive then looks kinda dead, and it's just the spin control
signal taking liberties with your good times. When no 3.3V wire
is on the cable, the expensive 24TB will spin up. Such drives can
take 20 seconds to spin up and self test, so be patient.
Paul
--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)