Re:Weird monitor bugs people sent me in the last 5 years
by qikInNdOutReply on Monday August 29, 2022 @03:20AM
(#32635524)
Cable shielding often is subpar on industry equipment too. Yes, they have bought shielded cables, no they have not connected the shielding to the expected locations on patch up. Or just wrapped it loosely around, so everytime somebody patches up a new RJ45, you get a new quality situation, cause the vibrations shake the roulett box. Finally, ground.. ground is the yellow green cable and it goes to ground - and ground should be something professional done. Not a network of suffering machinery, pumping hovering potential into one another.
Also dont trust all electricians. Lots of them just try and error, nod in terror. Some do not even speak the language of the e-plan they are cabling up.
Re:Weird monitor bugs people sent me in the last 5 years
by p_l on Monday August 29, 2022 @07:37AM
(#32636956)
A bit of a problem is that HDMI is very sensitive to EMC thanks to DVI (which forms its base) being essentially VGA minus the DAC step - there's even porches and overscan included in the signal. But this meant that you could make very cheap TV displays, which thanks to very limited set of frequencies involved in cables could be made to work "stable enough".
So imagine all the problems you could have, and multiply it by variable frequency cable that thanks to increases in resolution has to run way higher clocks than it used to, combined with being cheapest possible design, and that unlike it's analog origins an error in bitstream can now crash the connection instead of just causing temporarily off-colour area.
Re:Weird monitor bugs people sent me in the last 5 years
by dogleash on Monday August 29, 2022 @10:17AM
(#32638559)
>there's even porches and overscan included in the signal
Well, I guess this explains some of my "why the fuck is this even an option" when trying to make a TV just display the signal as it was received.
Re:Weird monitor bugs people sent me in the last 5 years
by p_l on Monday August 29, 2022 @10:27AM
(#32638707)
Yeah, the simplest possible circuitry for driving a flat panel TV from HDMI (except the HDCP block, which AFAIK can be placed inline before the display logic) would be to declare the 720i/p capability and then just... pump the data straight onto display interface with some buffers here and there meaning to drop the porches, driven all by HSync/VSync signal recovered from the HDMI clock. :V
Re:Weird monitor bugs people sent me in the last 5 years
by exmadscientist on Tuesday August 30, 2022 @05:42PM
(#32655522)
Incidentally, this is why DisplayPort is always preferable to HDMI if you have the choice. HDMI is kind of a stupid specification.
Because part of hardware engineering is making devices that function even in poor environments, and that tolerate foreseeable misuse. (This is a major part of medical device development, for example.) Cable shielding is always iffy on consumer-grade cables. If other vendors can produce monitors that tolerate its absence, because that seems to be reasonably common!, then if you can't, your products will be seen as inferior. Exactly as is happening here.