Investigating the HDMI "Green Screen After a Few Seconds" Problem

bottletop

Active Member
Don't get me started on EDID! My electriQ (sic) UHD monitor returns a manufacturer ID which is identified in the tables as "do not use". That means when I go into desktop settings, the desktop layout mapping to monitor(s) disconcertingly displays "do not use" as my main (only) monitor! Very confusing.

I cured it by editing the look-up table, but that means doing it again every time the OS gets updated.
I wonder if it's worth trying your troublesome HDR (and a working HDR) with this monitor? It may produce useful data points. If it green screens then the issue is most likely with the Humax. If it doesn't produce green screen then it may be to do with HDCP revocation list (assuming the monitor isn't linked to the internet). Although the EDID issue may throw this guess out.

I can't decide if my green screen HDR is an issue with hardware or software/firmware.
If it is hardware - it doesn't explain the ability to show the screen properly during pre-HDCP (as BH mentioned).
If it is software/firmware, then the only thing I can think of is the HDCP revocation list was tripped - making the HDR incompatible with my TV.

From these links some TV makes had issues with the HDR - LG, Samsung, Sony and occasionally Panasonic, Sharp.
(Jan 2012) https://community.sony.co.uk/t5/oth...ng-humax-hdr-via-hdmi-to-sony-kdl/td-p/282489
(Apr 2013) https://myhumax.org/forum/topic/green-screen-issue
(Apr 2014) https://myhumax.org/forum/topic/green-screen-1
(Oct 2015) https://myhumax.org/forum/topic/green-screen-saga#post-41394
(Oct 2016) https://myhumax.org/forum/topic/green-screen-2
(Mar 2018) https://myhumax.org/forum/topic/green-screen-3

In my case my first HDR purchase was June 2016. This developed an intermittent green screen issue. The green screen issue gradually got worse and became permanent in roughly 2018. I haven't had TV firmware updates since 2013, only CFW updates (but others have had the issue without CFW - so it can't be that).
My one developed issue like this one
I convinced myself that it was a timing issue caused by component ageing as, in my case the problem first showed up some years ago with a Sony Bravia TV, and got progressively worse over some months. When the Bravia was replaced by a Panasonic, the green screen went away. However, some years later, the problem has resurfaced very occasionally. It remains to be seen whether it gets gradually worse as before.
For info the Loader is 7.31. I didn't try changing it as others had reported no improvement.
It's so confusing.
 
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/df

Well-Known Member
Maybe ageing, or dust? The HDMI article I linked above explains that there is a capacitance limit outside which the I2C/DDC data exchanges that set up the link may be corrupted (PCB I2C: 400pF, DDC: 700pF). While a single domestic link wouldn't exceed that limit, might not ageing or faults and muck around the PCB traces and HDMI connectors have that effect?
 

bottletop

Active Member
Maybe ageing, or dust? The HDMI article I linked above explains that there is a capacitance limit outside which the I2C/DDC data exchanges that set up the link may be corrupted (PCB I2C: 400pF, DDC: 700pF). While a single domestic link wouldn't exceed that limit, might not ageing or faults and muck around the PCB traces and HDMI connectors have that effect?
I discounted faulty cable and/or TV socket issue because I changed cables(1m/2m) and TV HDMI sockets.
So HDR1(with green screen issue) doesn't work with the TV regardless of the cable or HDMI TV socket in use.
My other HDR works fine on any TV HDMI socket and cable combination.

So that leads me to think the issue may be with one STB - HDR1(with green screen issue).
eg hardware or software. Also remember this HDR1 works fine using HDMI output during the loader boot screen eg for firmware updates.

Or the issue is with the pairing of HDR1 with my particular TV.
Other people work around the issue by changing the TV or HDR.

I don't think the TV is at fault (or unlikely) because it works with other HDMI (STB/PC) devices, including another HDR.
 
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bottletop

Active Member
Saw this on eBay
It's a HD FOX T2 that has certain issues, including "Doesn't work with some LG TVs (displays a green screen on my model)"

Edit1: This is the full description of the item -

"Although this is fully-working in my setup (see pictures of it working) note the following important issues and information I found in my experience with it which may cause it not to work - please read before deciding to buy:
  • No remote control - I used the "HDMI Link" feature of my TV to remote control it and tune it - pre-tuned to West Midlands (Sutton Coldfield transmitter).
  • I tried a couple of unofficial replacement IR remote controls for it I bought on ebay, but these didn't work, so I'm not sure if it needs a real official remote control by the manufacturer, or if the IR sensor has an issue.
  • Without a remote control or HDMI control, tuning is only possible with a "System Flush Update File" on a reset USB key from HummyTV website as access to the reset/installation option requires entering 0000 as a code via remote control otherwise. Other operations like EPG and channel changing are fine using the buttons on the box.
  • Doesn't work with some LG TVs (displays a green screen on my model) - had used this fine with a HDMI Capture USB device for a computer with pass-through and that worked OK and could enable the HDMI Link and tuning.
  • Comes pre-installed with custom firmware from HummyTV website (see the wiki guide there - requires a USB stick to enable all features)
Will be posted same or next working day."
 
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OP
Black Hole

Black Hole

May contain traces of nut
Interesting. Might be worth picking up, but I have enough HD-FOXes. I've never tried ARC, and I don't think it has been discussed much on the forum (except a recommendation not to turn it on!).
 
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