Toshiba Signal Problems

Lazydog11

Novice Member
Hi all, hope I'm in the right thread for this...

Bought a brand new 55inch toshiba smart tv. Set up went OK but it won't pick up all of the freeview channels and all of the ones it does are horribly mangled and unwatchable.

It replaced an almost identical Toshiba smart tv, a 42 inch one. I tried putting that back and tuning it to see if it is an aerial problem but that tv tuned in perfectly. My neighbour is helping and brought his (also Toshiba) tv over and it tuned in fine too.

So there is an issue with this tv picking signals up from my aerial but I can't think what. Aside from that it works perfectly.

Any ideas?
 

Rodders53

Distinguished Member
Take your new TV to neighbours aerial and try it there?

Some TV tuners are 'deafer' than others... even the same brand (may be made by different factories, different internal parts).
Some TV tuners are super-sensitive and can be overloaded by too strong a signal with similar 'no signal' results.

TVs that work: what do their diagnostics report for signal level and quality on every tuned multiplex frequency?

Rare, but 'dead on arrival' electronics faults can happen. Maybe the tuner block is faulty.
 

A1944

Well-known Member
It could be the problem, which occurs sometimes, of the TV selecting a transmitter other than the one you need, resulting in weak and unwatchable signals from too far away.

Are there any channels listed with numbers in the 800 range?
 

Rodders53

Distinguished Member
It could be the problem, which occurs sometimes, of the TV selecting a transmitter other than the one you need, resulting in weak and unwatchable signals from too far away.

Are there any channels listed with numbers in the 800 range?
Unlikely with any recent TV... Freeview HD and Freeview Play specs should tune all and offer user-choice of the correct region; plus use the best quality signal automatically.

But @Lazydog11 was last seen having just posted the question...

Profile says "from Cambridge" = Sandy Heath plus Madingley for Local TV -- so when tuned the channels from it will be found first usually. Also Cambridge is quite close and relatively high field strength. (Tacolneston and Sudbury might be weak signals in parts, I suppose. Other transmitters would be even more distant and unlikely.)
 

Lazydog11

Novice Member
Take your new TV to neighbours aerial and try it there?

Some TV tuners are 'deafer' than others... even the same brand (may be made by different factories, different internal parts).
Some TV tuners are super-sensitive and can be overloaded by too strong a signal with similar 'no signal' results.

TVs that work: what do their diagnostics report for signal level and quality on every tuned multiplex frequency?

Rare, but 'dead on arrival' electronics faults can happen. Maybe the tuner block is faulty.
So the signal test shows 100% level and 100% quality on the old tv but only 70% level and 15% quality on the new one. Can't understand why.
 

Rodders53

Distinguished Member
Take your new TV to neighbours aerial and try it there?

So the signal test shows 100% level and 100% quality on the old tv but only 70% level and 15% quality on the new one. Can't understand why.
Different tuner modules in different TVs will give different figures.
My Panny TV showed 10/10 both before and after digital switchover when the power increased by 10x (10dB) as it metered after the automatic gain control and error correction systems. A Humax PVR gave more sensible numbers.

Check the centre pin 'socket' of the new TV to ensure it's making good contact with the TV plug. Ensure all hdmi cables are kept well away from the aerial wires.

The 15% quality is the big issue. Are there any aerial amplifiers (aka boosters) involved? If so can the aerial be temporarily 'direct' connected (using a joiner/coupler/double-ender) and the measurement repeated with a lower signal level input?
 

Lazydog11

Novice Member
Take your new TV to neighbours aerial and try it there?


Different tuner modules in different TVs will give different figures.
My Panny TV showed 10/10 both before and after digital switchover when the power increased by 10x (10dB) as it metered after the automatic gain control and error correction systems. A Humax PVR gave more sensible numbers.

Check the centre pin 'socket' of the new TV to ensure it's making good contact with the TV plug. Ensure all hdmi cables are kept well away from the aerial wires.

The 15% quality is the big issue. Are there any aerial amplifiers (aka boosters) involved? If so can the aerial be temporarily 'direct' connected (using a joiner/coupler/double-ender) and the measurement repeated with a lower signal level input?
Returned tv and exchange it for another identical one, same issue.

The aerial is using an amplifier. I plugged the cable directly into the TV and got zero signal, now I've gone back through the amplifier and it's still zero signal so actually it's worse than it was before.
 

Rodders53

Distinguished Member
Masthead amplifier power supply?? If so the amp stops working = no signal. Picture or make model numbers might confirm.

May still be worth taking to neighbour's aerial to try to tune in there?

Next one - if you're hell bent on buying this particular Vestel-made TV set (they own the licence for use of a Toshiba badge) - is to demand it's unpacked, tuned in and shown working in the shop before repacking and taking home?

:lesson: The adage: buy cheap, buy twice springs to mind.
 

mike7

Member
I agree with Rodders on both counts. People frequently make the mistake that the mains powered box that they they plug in at the TV set end of the aerial cable is an 'amplifier'. Usually the amplifier is either in the loft or on the actual aerial itself. The little black box is often just a power supply needed to activate the remote amplifier. Take it out of the equation and the amplifier will not work at all. When people move home they often take away these 'amplifiers' leaving the new occupant with a dud signal from the aerial.

There were some TV sets that provided the 12v power for remote amplifiers, but I think that is a thing of the past.
 

Lazydog11

Novice Member
Masthead amplifier power supply?? If so the amp stops working = no signal. Picture or make model numbers might confirm.

May still be worth taking to neighbour's aerial to try to tune in there?

Next one - if you're hell bent on buying this particular Vestel-made TV set (they own the licence for use of a Toshiba badge) - is to demand it's unpacked, tuned in and shown working in the shop before repacking and taking home?

:lesson: The adage: buy cheap, buy twice springs to mind.
Do you think a different brand would tune in better?
 

Rodders53

Distinguished Member
When people move home they often take away these 'amplifiers' leaving the new occupant with a dud signal from the aerial.
Often the removal company staff being 'helpful' and lack of instruction / labelling by the leavers.
Do you think a different brand would tune in better?
No idea.
Might.
Might not.

But the particular brand/model you've tried two of maybe has a basic problem. Hence, I keep saying Take your new TV to neighbours aerial and try it there to prove that issue, or not; in which case = your aerial is possibly the problem - over amplifying perhaps.

Details of this amplifier you have would allow more informed opinion on that over amplification bit.
 

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