Need help with very random freeview problem

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gjm

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#89846 9-Sep-2011 08:55

So last weekend I purchased a Panasonic freeview dvd player / recorder from JBHifi (this http://www.jbhifi.co.nz/tv-lcd-led-plasma/media-players/panasonic/250gb-freeview-digital-television-recorder-sku-18321/).

Hooked it up and everything worked fine for a few hours but then my picture on the screen went all screwy. Basically it looked like the pixelation they do to cover someones face on TV when they dont want to be identified but the whole screen looked like this. Bit strange I thought so turned it off overnight to let it do a firmware update. Tried again the next day and for several days afterwards but the same thing kept happening. Didn't seem to matter if I used HDMI or just the AV outputs the same thing would happen.

So I took the unit back to jbhifi yesterday and swapped it out. Plugged the new one back in, worked fine for a couple of hours and then bang, same problem.

So I've eliminated the unit as being faulty and have swapped both the HDMI cables and AV cables just in case but the problem remains. This suggests the problem must be between the aerial and the box somewhere.

Does anyone have any ideas on what I should check first? Just seems strange to me that it works fine for a few hours but then stops. When its working I get crystal clear reception, epg works well, everything just works. When it stops then freeview is unwatchable. Even turning off the box and just passing the signal straight through to the tv doesnt work well as there is a big horizontal line across the middle of the screen.

Any and all help appreciated :)

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B1GGLZ

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#518975 9-Sep-2011 12:54

Does your TV have Freeview built in and if so does it work OK when the antenna is direct to the Tv?
What happens when you play a DVD?
Pixellation is caused by lack of signal strength and has nothing to do with the HDMI, Component or composite connection to the TV.
In view of the fact this has now happend on two units I would be investigating the antenna and coax.

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gjm

787 posts

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#518983 9-Sep-2011 13:04

no other freeview source I can test with unfortunately. Playing DVD works fine. I guess I can start playing with the aerial and check the coax but since this is a rental I dont really wanna fork out $$ to get it replaced / get aerial guy in, and am doubtful that the landlord will want to either. Still, it needs fixing so I might just have to wear it.

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wazzageek

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#518987 9-Sep-2011 13:18

Do you have a UHF or VHF aerial on the roof?

we currently use a VHF (we're in a rental as well) - we have problems in windy conditions and sometimes during stormy weather. I've also noticed that some channels can suffer if recording a high def source. (e.g. TV1 HD and watching Channel 4)

When we first moved in, the aerial didn't work well - on a hunch we borrowed a set top box and tried the cable - analog wasn't too bad, but no signal for digital. Turned out the center pin in the wall outlet had been broken (meaning the cable from the outlet to the tv was acting as our aerial!)

Fixing the outlet plug has meant we can pick up digital signals, however I'm under no illusion that we are going to have to fork out some $$ for a UHF aerial.

Hope that helps you out.

richms

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#518988 9-Sep-2011 13:18

Is there any time of day or similar that the problem starts to happen at?

Richard rich.ms

gjm

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#518992 9-Sep-2011 13:26

we have a uhf and vhf aerial outside on the roof. The cable runs to just inside the house where I have attached an extension cable to reach where the tv is. I have tried just attaching the device directly to the external cable to rule out the extension cable as the cause but the problem still happens.

Analogue reception is ok on most channels. Maori TV, Trackside and other randoms aren't great but 1,2,3,4,Prime are all fine.

As far as I cant tell the problem occurs only in the evening from around 9pm-ish but I haven't been home during the day a lot to test so can't isolate this as a relevant factor but it could well be. I guess at night it gets cold / damp so maybe some moisture or something getting into the cable from outside?

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wazzageek

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#518995 9-Sep-2011 13:31

What is the signal strength and quality like?

It sounds suspiciously like there's something sending out some interference at that time of the day - especially if it's occurring at about the same time each night.

Also - Maori and trackside are broadcast on UHF - so it may be that your aerial is not pointing in the right place (or possibly not even connected)

richms

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#518996 9-Sep-2011 13:32

Or temperature of the amplifier if you have one, or someone starting up a noisy device at those times, or dew on trees that the signal has to get thru etc. Can be a prick to sort out but as your maori tv isnt good, it may be that you just have problems with the cable etc. How old? How old is the diplexer?

Richard rich.ms

gjm

787 posts

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#518999 9-Sep-2011 13:46

signal strength registers 9 out of 10 when being tuned in. When it is working all channels have a very good picture. According to the freeview website we are in the very likely to receive area. Unsure about the age of cable etc as it was all installed before we moved in (couple of years ago).

Ill do some more testing over the next few days and see if I can pin a time window on when it happens to see if there is a trend.

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gjm

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#519786 12-Sep-2011 09:18

so it's definitely either the aerial, the duplexer type box thing on the aerial or the cable. Problem was only happening late at night or early morning. I opened up the box on the aerial (I think its called a duplexer) and everything looked fine. Decided to stick a plastic bag over it in case moisture was getting in to it and all worked fine that night.

Sunday we had that torrential rain and it all went to crap again until it stopped and then back to normal. I guess I need to get a TV aerial guy to start fixing this now. Anyone got any recommendations for someone central Auckland who can do the job well?

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richms

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#519831 12-Sep-2011 10:33

They will probably bill $80 before the ladder is off the van.

IMO, get some new RG6, and run it from the UHF antenna straight to the TV. there is no need for a diplexer anymore, and most have trash screwdown terminals that should never have been used for UHF.

Richard rich.ms

B1GGLZ

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#519841 12-Sep-2011 10:59

richms: They will probably bill $80 before the ladder is off the van.

IMO, get some new RG6, and run it from the UHF antenna straight to the TV. there is no need for a diplexer anymore, and most have trash screwdown terminals that should never have been used for UHF.

+1

Get rid of the VHF antenna and run new RG6 direct to the TV. Sometimes the UHF digital tuners don't like the VHF antenna in circuit as well. The UHF antenna should be on its own and well clear of any obstructions including other antennae.
If the UHF antenna is old and corroded then consider a new antenna as well.

gjm

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#519847 12-Sep-2011 11:16

I might try disconnecting the vhf aerial altogether then and see if that makes a difference before replacing the whole cable run. Cant quite see what state the uhf aerial is in as its too far up the mast to get a good look but it's not falling apart or anything from what I can see.

If I do need to replace the cable run Ive found some rg6 here http://www.electricaldirectltd.co.nz/ecommerce.php?func=14&DCI=66&DPT=p&DPI=290&S=a8d5a34ee6745e70c413b45e30d3a2ee for .90c per meter... is that a good price / quality?

Thanks for the help so far.

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richms

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#519851 12-Sep-2011 11:20

gjm: I might try disconnecting the vhf aerial altogether then and see if that makes a difference before replacing the whole cable run. Cant quite see what state the uhf aerial is in as its too far up the mast to get a good look but it's not falling apart or anything from what I can see.

If I do need to replace the cable run Ive found some rg6 here http://www.electricaldirectltd.co.nz/ecommerce.php?func=14&DCI=66&DPT=p&DPI=290&S=a8d5a34ee6745e70c413b45e30d3a2ee for .90c per meter... is that a good price / quality?

Thanks for the help so far.

For per meter thats a reasonable price, if you are going to be running more cables in future consider getting a whole roll and chances are you can flick off any excess on trademe for a profit too

Richard rich.ms

gregmcc

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#520418 13-Sep-2011 12:53

Had a similar problem a while back, every evening around dusk the reception went to rubbish.

I was standaing at the window one evening while the TV was on, the street lights switched on, the street light just down the road in the direction the aerial was pointed had been vandalised and was flickering, the picture went to rubbish at exactly the same moment the faulty street light came on.

Have a look tonight as the lights come on, see what happens

Greg

gjm

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#520497 13-Sep-2011 15:03

interesting thought...Ill check that as well.

[Amstrad CPC 6128: 128k Memory: 3 inch floppy drive: Colour Screen]