this is a high quality cable right you know if i was doing a simple unboxing
i'd be fooled too it's got a nice flexible sheath sturdy strain relief
boots fair right rings for signal filtering i mean it says high speed
right on it they wouldn't lie would they they won it's a piece of crap it's dead
it's gone and how do we know thanks to total face who sent over their
advanced cable tester v2 this thing is
sick now it's industrial equipment so
it's not the kind of thing we typically cover but it costs a fraction as much as
competing solutions and we learned so much from using it that it absolutely
deserves some time in the spotlight just like our sponsor glasswire keep track of
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so what you might say you can test a cable big want to fight about it yeah i
do want to fight about it it's a very big one we first explored the idea of
doing LTT Store cables a couple of years ago but we ran into a major roadblock
while it's easy to find an overseas supplier who can produce every kind of
cable under the sun it can be very difficult not to mention costly to
validate their work you need an expensive oscilloscope custom fixtures
and perhaps most importantly a skilled
operator or you can treat yourself to
one of these but what exactly do you get for your
money well a 3 amp 12 volt power supply
all the associated cablery that's needed to operate the machine a tiny little
sheet outlining all of the reasons that total phase can invalidate your warranty
and the tester of course there's not really much to show on the outside you
got your power switch you got a lan and micro usb port on the back there's
no interface whatsoever so there's a little led here this is a non-touch
screen you don't actually interact with the unit at all other than this slot
right here so on the inside you've got these two
female slots and then the test boards for whatever type of interface you want
so this is an HDMI one just pop in like this and then they've got these little
like what are they quarter of a turn third of a turn lugs so it looks like a
big normal captive thumb screw but actually it's just super super fast to
install let's poke around inside shall we now that we've got this baby opened
up you can see the chassis is bigger than necessary but not by much
all the main board traces and components are nicely laid out and labeled so we've
got 12 volt dc power coming in right about there and it gets stepped
down into 3.3 and 5 volt on these lines
where they go uh there's 3.3 and there's five right about there and they've
worked some clever modularity into the design our test interface sockets each
with similar circuitry come out right over
yeah and then they feed out into what appears to be the processor stack on a
separate mezzanine board we did by the way note a couple of manually soldered
wires here but kyle from engineering says they're i2c lines and won't affect
anything so presumably it's the kind of thing that wasn't worth spinning up
another revision of the board for what i suspect does the actual processing is
this one right here and this one right here because those are the ones they've scratched out so yeah this is doing some
processing but this is probably more of a general purpose processor hosting the
web server and maybe taking whatever the outputs of these are this is actually
quite normal it's not like they scratched those out because they were sending them to the media it's really
common in the same kinds of places where cables get made cable factories for
people to try to reverse engineer the tools that they need to make and
validate cables so obviously anything they can do to protect their ip from
their customers even is probably a worthwhile step
in theory this thing is so simple to use
that literally anyone could validate pretty much any cable that they would
find on a shelf usb Thunderbolt lightning very very frightening display
port and even HDMI all the way up to version 2.1 which is a blazing 48
gigabit per second across four twisted pairs
let's give it a whirl on some of our many cables we're at the size now where
LMG owns a disturbing number of cables like literally
hundreds of them in every freaking
style and every freaking size
now we could test power cables but in our experience those have been mostly
problem free video cables on the other hand especially long ones or specimens
with odd terminations can and have given
us issues over the years like these monoprice DisplayPort cables
i don't know that this is going to fail but i have a strong suspicion that it
will i remember our first standing desk configs in the editing dent we used
these for the monitors and i remember them having a ton of problems with them
i'm starting with this displayport cable because i am
i am sure that there is something less suck about it these horrible cables
these cost so many headaches or maybe maybe it was something else
now we're going to know for sure just starts going love it
i knew it signal integrity it sucks let's have a look at the full report
though so we want to go into details here and things get real freaking
interesting on top of just pass fail which is all most people would need to
know here we can dig into this interactive diagram pin by pin we can
make our way down through all the different ways that it could fail so you
can see our dc resistance is actually within spec and
right there no freaking wonder in all the prep colin
did for this video i don't think you saw this did you it's time to make an e-waste bin the
next big re-org i want us to take every bin in every
cable and run them through the cable tester
we take all the ones that don't pass and we throw them away
never to be seen again you guys might be thinking that sounds like a lot of work
but compared to the amount of time that we waste trying to diagnose problems
that are ultimately caused by a crappy cable
oh let's have a look at how it's supposed to look with some cables that
stand a better chance of passing is this our e-waste bin by the way
see you later premium high-speed atc let's find out
shall we
oh my god all of these pins
here are supposed to have ground connections for
signal integrity and they just don't so while our signal integrity
passes here what could happen to this cable is that it could stop working if
there's something nearby that causes any kind of interference pretty crazy now i
said that the signal integrity passed but clearly you can see looking at these
charts that this is where the rubber hits the road from a science-y
perspective so we're going to throw over to professor riley to explain what the
heck we're looking at here thanks Linus eye diagrams are a visual representation
of the voltage on a pair of wires these lines here are your signal when
the signal is up here above the eye it's a one when it's below it's a zero and
that's binary data baby this gray hexagon outline shape in the
center is the eye and inside that is an
eye mask in blue that's a no gozo if any of our signal
lines enter the eye mask the receiving device won't be able to get a clean read
of the signal which means the cable cannot be trusted
now let's look at a perfect eye diagram every sample of our signal ends up
stacked right over top of the last with no imperfections this would allow us to
dramatically increase the clock speed of the signal faster signal more data
unfortunately in the real world no two samples will end up exactly alike and
there are two main ways signal noise affects a cable signal loss and jitter
really big cards signal loss is pretty easy to understand as the length of the
wire increases the voltage measured at the other end will fall due to the
resistance of the wire if it drops to within the eye well that's game over
baby that's why higher quality cables tend to use copper rather than aluminium
due to its superior conductivity
as for jitter well it's a little more complex but in a nutshell due to factors
such as electromagnetic interference and processing delays it's normal for signal
timing to vary this is mostly caused by the signal source and as you can imagine
too much variance puts us closer to the eye and closer to signal lost city
where data goes to die
that's all for this lesson don't forget to hand in your homework
bye bye now this one is poo poo
here's one of our longer HDMI cables this is supposedly a 4k uhd cable so
HDMI 2.0
oh wow that's a pass oh wow
you can see it's a a lot messier but oh
that's really close that's what happens when you have a super thin cable that's
longer though you got a worse conductor you get a worse freaking signal
integrity either way it's a keeper i want to see how close it can get for
HDMI 2.1 spec though
zero percent measured do we have any of our HDMI 2.1 cables
let's see if these cables we paid extra for for their HDMI
2.1 capabilities are even any better
that's fine just fine we got a keeper here this is your cable
let's find out if you wasted your money andy there's no way it's going to do HDMI 2.1
oh it's borderline look at that it's got 8 decibels 9
decibels lost 13 on the final pair yeah
that's pretty cool okay i'm in like cable testing mode here now
okay who's who's buyer's point okay buyer's point made this HDMI supposedly
2.1 cable you want to get called out buyer's point
called out in a positive way so now that we know how all of that
works does that mean we're gonna start reviewing cables
well yes but actually no we're not just gonna
take one cable and do a review of it that seems kind of ridiculous
but because cables are one area of
technology where snake oil and bs are still extremely prevalent i think
there's a lot of good that we can do by casting light on brands or product lines
that are not properly adhering to the standards and we want your guidance for
how to use our newfound cable testing powers for good HDMI 2.1 absolutely on
our hit list and usbc although
boy is that ever going to be a count of worms and a half and if you guys have got other ideas go ahead and leave them
down in the comments or hop over to our forum down below because we want to know
what you want to see and since i'm telling you guys what to do go check out
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