DTR-T4000 got me head scratching.

Dannysonic

Member
My Dad is elderly and lives in a council run assisted housing block.
He has an old Samsung TV he bought in 2008 as the main TV in the sitting room. It is HD ready but does not receive HD TV channels, only SD channels but the HDMI source inputs display HD 1080p.
The DTR-T4000 is in the sitting room so he can watch HD channels and BT Sports in there. Everything was working fine with the DTR-T4000. It picked up all the HD channels.
He bought a new TV cabinet and I went round, turned everything off, unplugged everything and set it up on the new cabinet. After doing that he could not receive HD channels. It just displayed a message saying "weak or no signal". I checked the ariel connections and it was fine.
I did a retune and this tuned in all the SD channels but wouldn't tune in the HD one's. I did a factory reset but still no HD channels. I tried 2 different fly cables from the wall ariel socket to the DTR-T4000.
I have an old DTR-T2100. I went home to get it and went back. It picked up HD channels no problem.
Now this is the strange thing that has me scratching my head. I brought HIS DTR-T4000 home and it tuned all the HD channels. I took it back to his but again HD channels displayed the weak or no signal message again.
He has a TV in his bedroom that is served by the same ariel and that picks up the HD channels.

Could anyone throw some light on why his DTR-T4000 does not receive HD channels at his house but does at my house, why my DTR-T2100 receives HD channels at his house and why the TV in his bedroom receives HD channels but the DTR-T4000 doesn't even though they share the same ariel?

As it is a council run 4 story building we don't have access to the communal ariel on the roof.
 

CatsWithThumbs

Standard Member
Hi - as a result of moving the equipment into the cabinet, are the aerial and HDMI leads now closer together? There can be interference between the two which affects some frequencies more than others, which is fairly common on these boxes. Simply ensuring these are well separated can often restore reception so definitely worth a try.
 

Rodders53

Distinguished Member
It's virtually 100% down to the new box location and cabling issues.

Remake any hand made plugs and sockets. Try alternative fly leads. Are you certain you have re-fitted the same cables in the same devices in the same order?

How is the bedroom TV fed (from a splitter in the Lounge, or via it's own feed from the Communal aerial system).

Picture of the communal aerial wallplate and cables attached (inc any splitter) may help us identify an issue?

Also use the PVR's Diagnostics signal strength and quality meter on all the received frequencies. Rarely (more often on highly amplified communal systems) things can be subject to signal overload and give the same symptom as low / poor signal.
It's possible the move has improved the signal into the 4000T and the 2000T is more tolerant of such a high signal.
(Equally the 2000T may be more sensitive to a weaker signal so works where the 4000T is needing more).
 

Dannysonic

Member
Thanks for the replies.
We actually tried 3 fly cables. One which was a cheap shop bought cable, the 2nd was a cable my dad had made up (he was an electrical engineer so child's play for him) and the third was another cable he made with shielded coax.
I can't get round to his for another 2 weeks to take photos.
The wall plate is just a 1 way plastic cover and a small metal 2 way splitter with one cable to the DTR-T4000 and the other is around a 15 meter cable run to the tv in the bedroom.
This is the splitter. Coaxial Connectors | Cricklewood Electronics
All the cables are fitted back correctly and apart from the different fly leads are the same cable that were working originally.
The new cabinet is in the same location as the old one and the cables all follow the same run as before. The HDMI and ethernet cables are secured together with velcro cable tidies to make it neater. The power cables and the ariel cables are hanging loose behind the cabinet. The HDMI's and the ariel cables are close but not touching
When I detached all the cables to move the TV and cabinet I did not undo any of the cable ties. I just unplugged all the cables, moved the old cabinet out, put the new cabinet in place, put the equipment back in the same position as before a re-attached all the cables.
I will try some new HDMI cable as the ones he has were purchased in 2008 when he bought the TV and may have inadequate shielding.
It's strange that it all worked perfectly before the cabinet change with the cables as they are now.
 

Dannysonic

Member
Sorry I've just seen I have been spelling aerial wrong.
 

Rodders53

Distinguished Member
Sorry I've just seen I have been spelling aerial wrong.
It's possible to use the 'Edit' feature to correct such mistakes. ;) I'm not bothered by such spellers tho' :p

Assuming the splitter is connected plug IN to the wall socket and then the two sockets OUTs feeding the two rooms:

One test is to remove the splitter and see if the 4000T then works with over double the signal into it (+4dB).
Or if that causes more trouble with it, such as other multiplex frequencies being lost it will suggest too much signal (overload).

Extra attenuation could fix overload and feeding the bedroom from the 4000T loop-through output the lack of signal. (Although power saving in standby would need disabling.)

If you can guide your Dad to make the diagnostic signal strength quality measurements and report them it'd be good. No problem if he can't though!
LCN 1 BBC One SD, LCN 3 ITV SD and LCN 101 BBC One HD will do for the 3 PSBs...
12 Quest for SDN, 17 Really for Arq A and 22 Ideal World for Arq B on the commercial multiplexes.

Ideally do it with splitter in place as now and repeat when the 4000T is fed direct from the wallplate.


:lesson: The one time I had problems with HD channels but the SDs were fine was when I'd rearranged my AV cab. A slightly too hard pull on a Belling Lee TV plug lead when reconnecting everything allowed in interference. Remaking the plug was a complete cure. {Even then, I didn't solder the centre pin like one should.}
 

Dannysonic

Member
My mistake. I should of said I had tried removing the splitter and plugging the lead from the T4000 directly into the wallplate. There were still no HD channels.
 

Rodders53

Distinguished Member
What are the reported signal strength and quality readings?

Humax generally have decent metering and are usually reported to be quite sensitive so can suffer overload from communal, highly amplified, systems.
 

Dannysonic

Member
What are the reported signal strength and quality readings?

Humax generally have decent metering and are usually reported to be quite sensitive so can suffer overload from communal, highly amplified, systems.
When I visit him next I will turn off and unplug everything apart from the T4000 and move the aerial fly cable away from any other cable to see if that makes a difference. Fingers crossed.
I'll also take the signal strength readings.
 

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