topic Re: Display flickery and snowy in Sky Q

Display flickery and snowy

millsy5 — Thu, 05 Jun 2025 08:56:11 GMT

Since I got Sky Q about 7 years ago I've been using a HDMI extender to extend the signal to a different room. I don't watch TV in the room that has the Sky box.

I've been using a TM-55 HD POE HDMI extender. There's a transmitter and a receiver. This takes the HDMI output from the Sky Q box, converts to Ethernet, back to HDMI and into the TV in the other room.

Sky Q --> HDMI --> TM-55 Tx --> CAT5 --> TM-55 Rx --> HDMI --> TV

Recently some of the channels were reporting no signal. I contacted Sky and did the basic debugging which didn't work so they sent an engineer out to me. He came yesterday and said the F-type connector looked loose. He cut it off and replaced it with a new one and then I had all of the channels back. However replacing the connector has caused problems with the signal on the output of the extender. It has gone flickery and snowy (white pixels on the screen). However when I connect straight to the TV from the Sky Q the picture is fine. Somehow having the new connector is affecting the signal in the extender.

To debug the issue I swapped out the patch cable, transmitter and receiver (luckily I have spares) but that didn't help. I'm thinking it must be the connector (although the signal is fine when directly connected to the TV) or maybe the Sky signal has changed and the extenders can't handle the new signal?

Re: Display flickery and snowy

nigea99 — Thu, 05 Jun 2025 11:13:42 GMT

@millsy5 wrote:

Since I got Sky Q about 7 years ago I've been using a HDMI extender to extend the signal to a different room. I don't watch TV in the room that has the Sky box.

I've been using a TM-55 HD POE HDMI extender. There's a transmitter and a receiver. This takes the HDMI output from the Sky Q box, converts to Ethernet, back to HDMI and into the TV in the other room.

Sky Q --> HDMI --> TM-55 Tx --> CAT5 --> TM-55 Rx --> HDMI --> TV

Recently some of the channels were reporting no signal. I contacted Sky and did the basic debugging which didn't work so they sent an engineer out to me. He came yesterday and said the F-type connector looked loose. He cut it off and replaced it with a new one and then I had all of the channels back. However replacing the connector has caused problems with the signal on the output of the extender. It has gone flickery and snowy (white pixels on the screen). However when I connect straight to the TV from the Sky Q the picture is fine. Somehow having the new connector is affecting the signal in the extender.

To debug the issue I swapped out the patch cable, transmitter and receiver (luckily I have spares) but that didn't help. I'm thinking it must be the connector (although the signal is fine when directly connected to the TV) or maybe the Sky signal has changed and the extenders can't handle the new signal?

hi @millsy5

The restoration of Satellite signal itself would have no bearing on output to your TV.

When you mention patch cable do you mean the HDMI from the Q box to your transmitter - if not I suggest this is the first thing to try

Re: Display flickery and snowy

millsy5 — Thu, 05 Jun 2025 12:58:01 GMT

I agree that restoring the signal shouldn't be the issue, but that's the only thing that changed.

A patch cable is basically a short Ethernet (CAT5/CAT5e/CAT6/etc.) cable. I've this short cable going from the output of the extender transmitter to the RJ45 port on the wall (that goes around the house to the port in the other room). I swapped that but no difference.

Re: Display flickery and snowy

nigea99 — Thu, 05 Jun 2025 13:10:42 GMT

@millsy5 wrote:

I agree that restoring the signal shouldn't be the issue, but that's the only thing that changed.

A patch cable is basically a short Ethernet (CAT5/CAT5e/CAT6/etc.) cable. I've this short cable going from the output of the extender transmitter to the RJ45 port on the wall (that goes around the house to the port in the other room). I swapped that but no difference.

Hi @millsy5 I thought it might be.

As I suggested have you tried a different HDMI cable from the SKY Q box ?

Re: Display flickery and snowy

Godfrey — Thu, 05 Jun 2025 14:01:41 GMT

@millsy5 What happens if you bring the HDMI extender receiver into the room where your HDMI transmitter is situated and then just use a short Ethernet cable to connect the extender transmitter directly to the extender receiver.

Godfrey.

Re: Display flickery and snowy

Chodley — Thu, 05 Jun 2025 14:20:43 GMT

Wonder if there's a bit of interference coming from that new f-plug, maybe put a little foil shroud around it to shield and see if it makes any difference.

does it help if you drop the res of the Q output?

Re: Display flickery and snowy

millsy5 — Thu, 05 Jun 2025 15:17:05 GMT

HDMI cable is good because the signal is perfect when connected to the TV next to the Sky Q box.

Re: Display flickery and snowy

millsy5 — Thu, 05 Jun 2025 15:18:07 GMT

I tried that and connected to the TV in the same room as the box and still have the same problem.

Re: Display flickery and snowy

millsy5 — Thu, 05 Jun 2025 15:30:54 GMT

Good suggestion about adding foil. Just tried that but no improvement.

By dropping the res of the Q do you mean to try a non-HD channel instead of a HD one? If so then I'm seeing the same issue on both.

Re: Display flickery and snowy

Godfrey — Thu, 05 Jun 2025 16:48:26 GMT

@millsy5 If you have HD recorded media available on your Sky Q receiver, what happens when you disconnect the LNB coaxial cables from your Sky Q receiver and use a recorded programme source to provide HD video to your Ethernet extenders.

Godfrey.

Re: Display flickery and snowy

Chodley — Thu, 05 Jun 2025 18:04:51 GMT

@millsy5 wrote:
Good suggestion about adding foil. Just tried that but no improvement.

By dropping the res of the Q do you mean to try a non-HD channel instead of a HD one? If so then I'm seeing the same issue on both.

No, not the content, the output resolution of the box.

Re: Display flickery and snowy

millsy5 — Thu, 05 Jun 2025 21:04:21 GMT

Great suggestion. I removed both coax cables and watched a recorded show but still had the issue.

Re: Display flickery and snowy

millsy5 — Thu, 05 Jun 2025 21:15:06 GMT

Ah ok. I didn't realise you could change the resolution. It was at 1080p.

Some really good news. I changed it to 1080i and the problem went away.

Strange that it had been at 1080p all along (well at least I think it was beause I never changed it or even knew about it) and worked fine but then when the connector was replaced I had this problem.

One thing I noticed when removing the coax cables (per the previous poster's suggestion) was that the copper core on one of the cables was very short. It was inside the connector whereas normally they would be outside the connector. Not sure if this is a problem but I wonder if the copper core broke off when the cable was removed. I'm not sure which one was changed by the engineer or if he removed both. I was half watching him while chatting to him and I think he might have only removed the cable whose connector was replaced. Not certain tbh.

At least I can now watch TV properly. At first glance I don't notice any resolution disimprovement at 1080i from 1080p so I'll know for sure after watching some shows.