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[Ronski]

Last night I came home from work to complaints that the wife couldn't send emails, and the kids couldn't get on the internet. I got home from work about 17:20, and had to be around some friends for dinner for 6, so didn't have long to investigate. Anyway I quickly found that the modem appeared to be dead, no lights and stone cold. So I grabbed my spare modem and plugged that in, unfortunately I had no time to update the firmware.

Checking my stats it looked a mess, the modem actually died around 13:30 yesterday, and here's my recent resync log entries.

28/07/2014 03:41 - RESYNC detected (DS 41880 Kbps, US 7819 Kbps), AS = 105, Retrain Reason: 0
21/08/2014 01:42 - RESYNC detected (DS 42449 Kbps, US 7808 Kbps), AS = 5, Retrain Reason: 1
21/08/2014 01:44 - RESYNC detected (DS 42501 Kbps, US 7923 Kbps), AS = 15, Retrain Reason: 1
21/08/2014 01:49 - RESYNC detected (DS 42578 Kbps, US 8177 Kbps), AS = 7, Retrain Reason: 1
21/08/2014 02:03 - RESYNC detected (DS 42785 Kbps, US 8170 Kbps), AS = 5, Retrain Reason: 1
21/08/2014 02:21 - RESYNC detected (DS 42630 Kbps, US 8177 Kbps), AS = 59, Retrain Reason: 1
21/08/2014 02:46 - RESYNC detected (DS 42527 Kbps, US 7778 Kbps), AS = 60, Retrain Reason: 1
21/08/2014 03:23 - RESYNC detected (DS 42966 Kbps, US 7994 Kbps), AS = 7, Retrain Reason: 1
21/08/2014 03:55 - RESYNC detected (DS 42527 Kbps, US 7815 Kbps), AS = 35, Retrain Reason: 1
21/08/2014 04:03 - RESYNC detected (DS 32186 Kbps, US 5155 Kbps), AS = 14, Retrain Reason: 1
21/08/2014 17:46 - RESYNC detected (DS 41338 Kbps, US 8270 Kbps), AS = 55, Retrain Reason: 0
22/08/2014 03:45 - RESYNC detected (DS 39848 Kbps, US 7246 Kbps), AS = 29, Retrain Reason: 2

I now actually have downstream interleaving of 2551, with an imp of 6, and upstream interleaving of 91, with an imp of 2.5  The firmware and software also auto updated this morning.



Hopefully things will improve given time, and I need to get on Ebay and get another spare modem, which I'll update with the latest unlocked firmware and then swap my modems around.

If anybody would like to do a post mortem on the deceased modem then let me know.

[kitz]

Only had a quick look.  Normally I'd assume a lightning storm, but if it lasted for 2 hrs and was that bad, then Im certain you would have noticed it and mentioned it.  So some sort of local power surges?

Your attenuation @ 2amish is interesting,  Im going to ignore D3 and U2 as they could possibly be explained by those ranges coming into and out of use - hard to say without seeing corresponding bitloading. U1 is rather strange though. Its in both signal and line attenuation.

Looking at your Err Secs, it gives an impression of more like several short sharp noise that takes the line out of sync, rather than something more static.


--
edited to correct U1 typo

[Ronski]

Thanks kitzs, I don't think we had any rain/thunderstorms yesterday, and no problems with other equipment.  I had noticed over the previous few days some big spikes in FEC errors, don't know if that's related. At least my sync speed picked up, it got as low as 32Mbps which is ridiculous at 450 meters, just got to wait for the interleaving to drop.

I'm sure BE1 will take a closer look at the graphs when he gets chance.

[burakkucat]

You mention that the modem was cold. So what about its PSU? 

Did you swap over the PSU when you installed the spare modem? If yes, how confident are you that the original modem has failed and not its PSU?

I'll suggest checking the original PSU with a DMM. 

[HighBeta]

A spare  ECI/r PSU works well on HG612.

The LEI  MV12-Y120100-B2 produced less noise than the HG612  HW-120100B12W (white psu).

Just an observation , not an asbokid or burakkucat style a lab test   

[NewtronStar]

Any working PSU with 12Volts at 1 amp with a female plug 2.5mm will do to test.

[Ronski]

I meant to say the power supply was stone cold as well, and thanks to every one that replied.

Anyway the mystery of the failing HG612 has been solved.

Cause:



and effect:



I checked the modem today when I got home and noticed the sides of it was wet, which was odd as I couldn't see any water until I looked at the ceiling  Stained patches and a single drip, so I quickly whipped the power supply out of the modem. Investigation in our en-suite above found the valve for the sink leaking slightly and running down the pipe 

So it was a case of turning the water off at the valves, getting out the spanners and fixing the leak. The strange thing is that both sides of the modem were wet, yet the top/bottom was dry (as mounted on the wall). I took the modem apart just to make sure it was still dry inside, which it was, so also updated the firmware to the unlocked GUI version.

I've got a towel wedged up on some trunking which runs around the top of the wall to collect the rest of the drips, just going to have to keep an eye it, it's going to take ages to dry out.

I also checked the power supply output, and on my cheapo DMM it was showing 12.02v.

[NewtronStar]

That power transister looks in a bad state and the lower capacitor is bulged at the top 

[kitz]

Glad you found out what it was.  Hope you manage to sort the damage.

[Ronski]

Was very lucky it was only a small leak, only damage was a discoloured ceiling and a blown modem,  and huge amounts of interleaving. My server is sat in the corner there and that would cost a fortune to replace, not mention the grief. Ceiling will dry out given time.

[Bodge99]

Hello,
 
I might be able to do something with this one.. Would you like me to take a look at it for you?

Bodge99

[Ronski]

Hi Bodge99, if you'd like to take a look PM me your address and I'll post it to you, thanks.

[Chrysalis]

ouch thats a nasty bump on your latency.

[Ronski]

Sure is, I wonder just how long before the DLM relents.

[Ronski]

Seems like the DLM has relented already