150M Frustrating virgin media internet cut outs....

j4g3d · 05-05-2016, 15:41

Can someone please help me out? I am new on the forum but i have been lurking for a while!.

Anyway, i am on VM 150mbps and the speed is OK i generally get a consistent speed. However the issue i have is constant disconnections. Its been going on for a year almost. VM engineers been out 5 times. I only have the internet package but i do have a old box which i use for freeview channels.

So when the engineers came out they have replaced EVERYTHING from the outside wall of the house to new cabling inside the house. They have upgraded my router twice (once a refurb) and lastly a superhub 3 (or whatever the latest one is called). I use a ASUS router so the superhub is in modem mode. I have a coax splitter which i've also replaced 3 times to rule out this as the problem. I have removed splitter completely thus removing the tv box..etc. Problem STILL occurs. I have removed my ASUS router and used the superhub as the router, problem STILL occurs. I have upgraded cabling inside my house from cheapo coax to RG6 cabling. The cabling from the router/splitter is a maximum of 3 metres.

After getting endless engineers out, listening to random excuses and spending lots of money on cabling, connectors, splitters. I then spent more money and decided to get a yellow brick power booster as i was told my power levels were a little low. So now i can adjust power levels to my taste. But upstream levels tend to be on the high side peaking at 56dbmv sometimes, which i can't seem to adjust at all.

The internet cut outs are so frustrating!. I don't know what to do next. I believe i've changed everything and tested everything. Its GOT TO BE a problem at the VM box on the street but virgin won't do anything about it, they say the power levels and internet is stable and fine every time they arrive (which it is). Some days it lasts a week or 2 without any cut out. Since i bought the yellow brick its improved dramatically but still not right. Before i installed the yellow brick i got disconnections DAILY. It could be a couple weeks without a cut out then in 1 day it happens 10 times with the yellow brick, so much improved but still not right. I am thinking of getting a attenuator to lower the upstream power levels, but i need further advice from any experts out there?.

Yesterday when the internet cut out i quickly checked power levels..etc and this is what i got:

http://imgur.com/x60Xd7Y

http://imgur.com/oKCjMMv

I do not want to call VM again they are useless. I rather either sort it myself or cancel with them. The price keeps going up twice a year but the quality of the service is getting worse!.

Right now here is my power levels...

http://imgur.com/SEMwP7J

http://imgur.com/ylex42J

heero_yuy · 05-05-2016, 17:55

Welcome to the forum.

Your down power is in spec but the RXMER is bad. Upstream power is too high for QAM64 to be reliable. At 56dbmv even QPSK could struggle.

I know it's a pain with the call centre but it really needs a tech visit. Try first thing to get a UK CS.

They really need to address the high upstream power to start with. A while ago mine was like this and the connection was really flakey. The previous tech visits have been wasted time as they haven't actually addressed the real problem of the taps in the cabinet.

MUD_Wizard · 05-05-2016, 18:16

That looks like an SNR fault (the RxMER is very low, which is the give-away), which can happen without there being anything wrong with your setup. I get SNR fault's now and again, but normally my power levels and SNR are totally fine. So this shouldn't be happening all the time.

If high upstream power was the only problem you have then I would have said you need something like an Active Return Amplifier: https://www.youtube.com/watch?v=kxarSx0rQ9M

You may need a coax re-pull if the cable from outside your property to the cabinet is not good enough.

Your RxMER should be above 34.5 dB for a decent quality signal. The Hub 3 is doing a good job holding on at 33 dB.

Attenuators won't fix your upstream. Most attenuators are for correcting the downstream.

Your upstream level could be improved by changing the tap at the cabinet, but I'm not sure that's going to help. It won't change the downstream SNR and your upstream SNR could be low too.

Btw, your modem would support a higher downstream power up to +10 dBmV totally fine. Usually the downstream and upstream are related and work in opposite directions. However with your problems who knows. The upstream power is high because the CMTS can't hear the modem, so the modem is increasing power to be heard.

The upstream power limit for two 64 QAM channels is 54 dBmV. So those channels should work until the power maxes out. Ideally you want the upstream power in the 35-49 range, as they may drift a bit and you want a bit of leeway.

If the current tech's haven't solved it, the principal tech should be called.

Hope that helps.

You may get better advice from one of the cable tech's on here.

heero_yuy · 05-05-2016, 18:30

Agreeing with your general thrust. My take is that if the upstream power issue is sorted on the cab tap, this will up the DS power helping the RXMER (SNR) and then a local FPA to get the DS power right.

There again I'm no expert here. Just a passing engineer.

MUD_Wizard · 05-05-2016, 18:38

Quote:

Originally Posted by heero_yuy

Agreeing with your general thrust. My take is that if the upstream power issue is sorted on the cab tap, this will up the DS power helping the RXMER (SNR) and then a local FPA to get the DS power right.

There again I'm no expert here. Just a passing engineer.

Yes, to FPA after changing tap, though probably not needed with his levels, but...

No, the RxMER won't be changed by modifying the downstream or upstream power levels.

Unless it's a faulty tap causing the SNR problems in the first place.

heero_yuy · 05-05-2016, 18:49

My take is that if the SNR is a local problem then upping the DS power at the cab (by the tap change to correct the up stream power) aught to improve the SNR. The FPA suggestion is just to bring this into the ideal range for the modem.

But what do I know.

MUD_Wizard · 05-05-2016, 18:59

Quote:

Originally Posted by heero_yuy

My take is that if the SNR is a local problem then upping the DS power at the cab (by the tap change to correct the up stream power) aught to improve the SNR. The FPA suggestion is just to bring this into the ideal range for the modem.

But what do I know.

If you increase signal power, noise increases by the same amount. So the SNR ratio (ratio of Signal to Noise) is exactly the same.

heero_yuy · 05-05-2016, 19:01

Quote:

Originally Posted by MUD_Wizard

If you increase signal power, noise increases by the same amount. So the SNR ratio (ratio of Signal to Noise) is exactly the same.

Depends where the noise is getting in.

MUD_Wizard · 05-05-2016, 19:14

Quote:

Originally Posted by heero_yuy

Depends where the noise is getting in.

Yes, but that's unknown right now. We shouldn't guess where the problem lays and instead guide the OP to getting a better quality field technician who has better diagnostic ability.

heero_yuy · 05-05-2016, 19:19

Quote:

Originally Posted by MUD_Wizard

Yes, but that's unknown right now. We shouldn't guess where the problem lays and instead guide the OP to getting a better quality field technician who has better diagnostic ability.

Agreed. But if the noise was a general issue more customers would be affected?

And this would raise the issue at VM high command.

Either way the OP needs a senior tech visit and investigation of the issues.

vm_tech · 05-05-2016, 19:44

I wouldn't be putting your own amplifiers in, that one you've fitted could be causing all sorts of issues

MUD_Wizard · 05-05-2016, 19:45

Quote:

Originally Posted by heero_yuy

Agreed. But if the noise was a general issue more customers would be affected?

And this would raise the issue at VM high command.

Yes but 33 dB RxMER is well within VM's thresholds. So they will think that's fine. Hence the cable techs seeing no problem.

Other people may not have the same problem with upstream power as they'll be on a different tap.

Quote:

Originally Posted by heero_yuy

Either way the OP needs a senior tech visit and investigation of the issues.

Agreed.

j4g3d · 05-05-2016, 19:47

Thanks all for the valued information.

How does one get a senior tech to come out?, i've spoken to CS in the UK once and they're the ones that ordered me a fresh superhub.

I have just cranked up the yellow brick to see if the RxMER changes if at all.

DOWNSTREAM
Power Level (dBmV)10.97-11.52 - 10.88 - 10.60 - 9.92 - 10.52- 11.09-10.72
RxMER (dB) 37.09 -37.94-37.09-37.09-37.09-37.09-37.09-37.09

UPSTREAM:
Power Level (dBmV) 52.00 N/A N/A 56.00

MUD_Wizard · 05-05-2016, 19:50

Quote:

Originally Posted by vm_tech

I wouldn't be putting your own amplifiers in, that one you've fitted could be causing all sorts of issues

Yes, or doing DIY coax.

---------- Post added at 19:50 ---------- Previous post was at 19:48 ----------

Quote:

Originally Posted by j4g3d

Thanks all for the valued information.

How does one get a senior tech to come out?, i've spoken to CS in the UK once and they're the ones that ordered me a fresh superhub.

I have just cranked up the yellow brick to see if the RxMER changes if at all.

DOWNSTREAM
Power Level (dBmV)10.97-11.52 - 10.88 - 10.60 - 9.92 - 10.52- 11.09-10.72
RxMER (dB) 37.09 -37.94-37.09-37.09-37.09-37.09-37.09-37.09

UPSTREAM:
Power Level (dBmV) 52.00 N/A N/A 56.00

Right, so take that thing out and let's see what the levels are like without it.

vm_tech · 05-05-2016, 20:35

You could also be amplifying any issues and putting them back out on the network. And if you've got a 56db upstream with the amplifier in, either that amp isn't doing much or its gonna be non existent.