Probable Overheating Street Cabinet

[Peter_]

Originally Posted by Rimmer100

Upstream transmit Power Level : 61.0 dBmV

Way to high and requires a engineer to adjust.

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[on in an hour!]

Originally Posted by Rimmer100

First hot day since I last posted, so my internet is out. Connecting via a mobile phone to post my 'hot' modem levels:

Upstream Lock : Not Locked
Upstream Channel ID : 2
Upstream Frequency : 29200000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 61.0 dBmV
Upstream Mini-Slot Size : 2

Downstream Lock : Locked
Downstream Channel Id : 1
Downstream Frequency : 330750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : -7.4 dBmV
Downstream SNR : 28.4 dB

Guess I'm going to have to take some time off and get an engineer out. Unless you can buy the attenuators etc online so I don't have to bother

As before the online light is out on the V+ box too. Out of interest what does the V+ box use the network for? Is it just firmware updates etc?

rimmer,
attenuators REDUCE your signal,thats why i suggested if there were any on your equip to take them off as this would improve your signal level and therefore your upstream transmit power level would reduce,(which is better)and so your downstream.
the set tops require connectivity for your on-demand services to work.all on-demand is stored on external servers which require a 'return path' between them and the set top.

[Rimmer100]

When you put it like that, it makes sense regarding the attenuators. Don't really understand how the power levels relate to each other so thanks for clearing that up.

I understood how on-demand worked just hadn't made the connection between that and the online light at that point. Before you even replied I had found it out as I tried to watch Top Gear from Sunday and was told the service was unavailable. To be honest this will be the main reason for me to want to get an engineer out as I don't record programmes if I know I can get them on-demand.

Many thanks for all the advice from everyone. I'll post my levels again the next hot day after an engineer visit so you can see how well they have tweaked my levels.

[Rimmer100]

Brilliant, the applications that they use to log support calls are down! Guess I'll have to wait until tomorrow to book the engineer

[Peter_]

Originally Posted by Rimmer100

Brilliant, the applications that they use to log support calls are down! Guess I'll have to wait until tomorrow to book the engineer

What do you mean have you just rang up.

[Rimmer100]

Yes I had just rang and the person on the phone had told me that their systems were down.

So an engineer came out today to have a look at my problem. Unfortunately he couldn't do anything about it. The coax run from the cabinet to my property has been done using the standard cable. As the service is being split for the V+ and Broadband this coupled with the long run means that the amount of signal drop is too much to compensate for with boosting the power etc. I now need to wait until 8th July for them to run a thicker gauge cable to the outside brown box which will hopefully solve the problem.

Looking at the weather forecast it is unlikely I will be having much internet or ondemand usage for the next week!

It does amuse me that Virgin bang on about their fibre optic network when the last 100s of meters are all in coax. I'm guessing that if they ran fibre to the houses it would solve a lot of issues with signal loss etc.

*Wanders off to dream about fibre to the house*

(Yes I know it would be expensive and the equipment cost would be ridiculous etc)

[alex250]

just get network to set the return path levels on a hot and sunny day, then you'll be in spec when its hot and even more so when its cold, you would need a service lad to refer it to them

[on in an hour!]

if the splitter for the 2 feeds is in the external termination box and the signal is ok at that point they can fit an HDU,its a powered splitter that doesnt suffer any loss through it outputs like traditional splitters.

[jgrove]

I gave up with 50 meg 4 months of snr problems i went back to 20 meg and all is fine! I have no idea why, but the suggestions in these forums were never offered even by senior installation engineers.

[raybo62]

Originally Posted by Rimmer100

Hello,

I think I am suffering from the dreaded Green Cabinet Overheating issue and I was wondering if anyone has any ideas of how best to raise this with VM.

The installation is only a few months old, so new cable was run to the flat. I had noticed that toward the end of the day the 'Online' light on my V+ box would start flashing. Didn't think anything of it until Sunday afternoon when it was the first truly hot day of the year and I lost my broadband as well. (It had been working in the morning). The ready light was flashing and the modem was dishing out a 192.xxx.xxx.xxx address as it couldn't talk to the servers.

I duly phoned VM after checking there weren't any outages in the area. I spoke to the broadband operative who decided that my modem was clearly faulty. Clearly. He wasn't interested by the fact that the V+ box wasn't 'Online' either. So I made the appointment later in the week knowing full well by the next morning everything would be fine. Low and behold the next morning, once everything had cooled off, I had broadband again.

Yesterday the same thing. Got home from work when the cabinet had been toasting itself and I had no broadband. Left to do some stuff, came back at 9PM and the broadband was back up. It seems the V+ box is more sensitive as it generally doesn't sort itself out until some point during the night.

The modem was changed when they (finally) did the installation in February / March. It is completely open to the air and doesn't get that hot.

What is the best way to get VM out to check the cabinet? I really don't want to have to take time off work for them to come and not see a fault because it happens to rain, when they just need to check their cabinet in the street.

The cabinet is situated in a position where it takes full advantage of getting baked all day.

Would wrapping the cabinet in tin foil help to reflect the heat, thus keeping it cooler and give passer's by something to laugh at or would strapping a garden parasol to it be better? Would dousing the cabinet with water, cool it down sufficiently to prove my point?

Any suggestions would be gratefully received.

This used to be an NTL area by the way.

you cant do anything about the cabinets all the engineers can do is open the doors to let them cool down some have had air vents installed some with fans that kick in when they get too hot but they arent wired up to the electrics ?

[Feenix]

Originally Posted by on in an hour!

rimmer,
attenuators REDUCE your signal,thats why i suggested if there were any on your equip to take them off as this would improve your signal level and therefore your upstream transmit power level would reduce,(which is better)and so your downstream.
the set tops require connectivity for your on-demand services to work.all on-demand is stored on external servers which require a 'return path' between them and the set top.

What a load of rubbish. The attenuators used these days are FORWARD PATH ATTENUATORS. Removing a FORWARD PATH attenuator will do little to reduce the RETURN PATH (upstream) power level (maybe 0.5dB) The OP obviously has serious issues with the SNR, but without seeing it first hand, it is anybodies guess. An RG11 repull may do the trick, hope Rimmer comes back to let us know.

[on in an hour!]

mmm rubbish eh?? so how come on a daily basis i have sacm's and set tops locking on in the high 50's,removing attenuation (which is just the same as upping the drop in the cab),allows them to lock on lower?

[raybo62]

Originally Posted by Rimmer100

For completeness here are my 'cool' modem levels:

Cable Modem Upstream
Upstream Lock : Locked
Upstream Channel ID : 2
Upstream Frequency : 29200000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 51.0 dBmV
Upstream Mini-Slot Size : 2

Cable Modem Downstream
Downstream Lock : Locked
Downstream Channel Id : 1
Downstream Frequency : 330750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : -7.2 dBmV
Downstream SNR : 27.4 dB

if you have a downstream lock of 330750 either you need a new modem or something else has happened downstream should lock onto 331000 or 339000 unless you have 50mb

[on in an hour!]

Originally Posted by on in an hour!

mmm rubbish eh?? so how come on a daily basis i have sacm's and set tops locking on in the high 50's,removing attenuation allows them to lock on lower?

just to add feenix,i know your quoting the science of FP attenuators (just so you know i have been service teching for 15yrs and was around at the inception of digi with C&W,and all the problems related with the original attenuators,especially with homes close to cabs were you attenuated highly to get required levels only for the mcns to drop off,hence the introduction of FP attenuators)
but im only advising the OP what i would, in the first instance,and especially if he was on the top tap,do.RG11 may solve his probs but he may want to get the rtn path levels checked by the network guys at the cab also

[alex250]

Originally Posted by raybo62

if you have a downstream lock of 330750 either you need a new modem or something else has happened downstream should lock onto 331000 or 339000 unless you have 50mb

Dual Docsis area has a mcns at 330.75 aswell as 586.75, mcns frequencies do vary from area to area tho