loss of RF input

cdmackay

cdmackay

Active Member
my T2 seems to have lost RF input entirely.

0/0 on all muxes, this happened yesterday evening, after successfully recording programmes during the day.

Retune finds 0 channels. My aerial plugs directly into the T2, no splitters, amps, etc. Has been fine for years.

Aerial seems to be fine: plugged directly into telly finds 100+ channels. My friend brought his spare T2 around, and that works fine too.

My T2 is otherwise fine: can play back already recorded material.

So it does seem to be the RF part of my T2 that's at fault.

I don't recall seeing many posts like this; is this a common failure mode, does anyone know?

I'll pickup another from ebay, but just wondering if mine can be revived?

thanks…
 
The only possibility I can think of is if a factory reset can sort it out. Before returning, the individual tuner test in the hidden service menu might have revealed whether this is a single tuner failure or if no signal is detected on either.

There was one similar report I can recall, but that is all.
 
thanks! I forgot about the service menu, I'll give that a try.

Once I've done a final backup of CF settings etc, I'll try a reset too.

ta!
 
cdmackay said:
thanks! I forgot about the service menu, I'll give that a try.
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I don't know whether that will work after you lost your tuning.

cdmackay said:
Once I've done a final backup of CF settings etc, I'll try a reset too.
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Factory reset won't affect CF settings, and your schedule is backed up in the CF. It's just the user preferences which need to be set up again, and most of those can be enforced by bootsettings.

https://hummy.tv/forum/threads/is-there-a-good-time-to-retune.7624/post-103888
 
ah thanks; I had some vague memory that a reset would wipe out part of the CF, but not sure why I thought that.

thanks again.
 
prpr said:
I would say it's friar tucked, permanently.
You haven't had water tracking down the aerial cable have you?
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I fear you're right.

Now, that's an interesting comment. When I undid the coax connector, I did indeed get the impression that it felt a little damp; my friend wasn't quite so sure. It wasn't dripping wet, for example.

Has that been a known problem in the past?

I'd discounted it, initially, since my Humax gets no signal, but both the telly, and my friend's Humax were quite happy with it.

But it's now occurred to me that perhaps water getting into the Humax might have killed it, whereas the telly and my friend's Humax aren't (yet) dead, and so would be fine, for a bit. We did use a stub of fresh coax between the existing cable, just in case.

I should add: it's not water coming down the outside of the coax, which is dry, and nowhere near where it comes through the wall, but I wondered about it having got inside.

does this sound like a possibility?

If so, I should make very sure of that, before putting a replacement Humax on the cable (or at least, continue to use a stub).

Has water ingress been known to cause this before? I just wonder why you mentioned it…
 
cdmackay said:
Has water ingress been known to cause this before?
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Potential water ingress from tracking down the internal cavities in some types of co-ax is certainly known about and has been discussed, and applies to any receiver including HDR-FOX, but I would expect visible corrosion in or around the UHF socket if that were the case.
 
cdmackay said:
does this sound like a possibility?
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If you have a single length of cable from the roof to the Humax, absolutely.
The inside of most coax is like a bundle of small pipes. So if water gets in, either by leakage at the aerial termination or if the cable has chafed in the wind where poorly fixed (or plain old age cracking perhaps), then it will end up at the the lower end eventually. It's probably got nearly 1bar head at the bottom, so it doesn't matter if the cable goes down low and then back up to the TV, etc - the water will arrive.
 
But in that case might there be a "straightforward" repair by replacing or cleaning the connector and/or detaching the RF shield and cleaning up the tuner PCB underneath?
 
/df said:
But in that case might there be a "straightforward" repair by replacing or cleaning the connector and/or detaching the RF shield and cleaning up the tuner PCB underneath?
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It might indeed be feasible but I don't recollect a single report of anybody actually doing it successfully.
 
I've had a similar problem with water ingress into a tv set. Ended up with no channels. Fortunately used a set top box instead and continued to use the tv that way - having taken steps against future water problems. Some time later (no I can't remember how many days or weeks) I tried the tv tuner again and it worked. It had dried out naturally and started working again, and carried on working until the tv failed for other reasons. Whether you could dry out the tuner and PCB more quickly I don't know. If the alternative is dumping your Humax it could be worth a try.
 
MikeSh said:
The inside of most coax is like a bundle of small pipes.
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Not strictly true for 'most coax'. 'Most older coax' perhaps, but modern stuff of any repute has a foam dielectric insulation between inner and outer and does not suffer from that problem.
 
Thanks very much indeed for all the comments, most helpful.

I will have a good look at the board & connectors, and also see if drying helps. I do have a spare Humax somewhere I think (!) if i can find it.

I'l try some blotting paper to really verify if the cable is wet. I can of course replace the entire aerial cable, but would rather be sure that it was needed. It's not dripping wet, there's just a very slightl wet feeling to the connector, on removal. Could be grease, or some breakdown of insulation etc, it's hard to tell.

I'll obviously not use the cable as is on anything directly. I think it might be OK for a short while via a stub of fresh cable, unless the water forces its way along the central conductor :)

It is an old cable (could be decades old) so it may not have foam. I'll try cutting off an inch and having a good look at it.

I agree that the head could force water along the 10' or so of horizontal travel it has before it goes up to the Humax. And we get a lot of rain :)
 
Trev said:
Not strictly true for 'most coax'. 'Most older coax' perhaps, but modern stuff of any repute has a foam dielectric insulation between inner and outer and does not suffer from that problem.
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I suspect that most of the currently installed coax is 'open' (I've still got half a drum in the garage), but the OP has confirmed his is old.

I don't know the foam will entirely block water travel, though it would be harder. There is still going to be a bit of airspace in the stranding of the screen, so given time (and one thing these cables have plenty of is time) a leak could possibly still get water down to the far end.
 
@cdmackay . Take/cut the plug off then shake the cable onto a bit of glass (mirror, picture frame etc.) and look for droplets. If you get any, don't muck around, just change the coax for some decent stuff.
 
cdmackay said:
what's that orange stuff on the main board, around the RF IN daughter-board?
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Rust staining. Doesn't look good, especially as that's the input can (might have still had a working half if it was the output can, but then it wouldn't be!).
 
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