Openreach Modem Power Adapter

So my internet just went down.

I noticed I could not get the web interface to load so I went downstairs to take a look at the Modem and noticed it was off and I could smell burnt electronics. So something had given off the magic blue smoke but the smell was not coming from the Modem.

So I unplugged it and noticed that's where the smell was coming from. Got another 12v 1A adapter and plugged that in, all working.

So why would a power brick just fail like that?

I am about to rip it open to take a look and see what died.

Here are some pics

http://s79.photobucket.com/user/seansmit17/library/P...

Look like the input protection done its job?

Edited by Seansmit17 (Thu 16-Oct-14 17:02:25)

So why would a power brick just fail like that?

'cos it's made in China !

Thinking out loud...

Will you be asking your ISP to provide a replacement as I guess they supplied it?
Not everyone would have a power supply to hand.


I bought a backup OR ECI modem and power supply from the Kelly engineer that installed my FTTC. Might have been £15 I didn't need to spend
I was hoping to hack it to get stats before I realised the ECI were a bit tricky!

What is the rating of that one? Is it a 700mA or 1A device?

Looks as though the switch mode controller failed or was destroyed. Question is, what caused it? Is your modem running hot - with a potential failure resulting in excessive current requirements? or was there a fault inside the PSU? Just keep an eye on the modem for a while.

In reply to a post by Seansmit17:

So why would a power brick just fail like that?

As Zarjaz says. Plus - it looks like a black one that came with the original OR HG612 modems. 0.7mA.

The ones with the HG612 B modem are white, 1A IIRC. Which modem do you have?

Edited by RobertoS (Thu 16-Oct-14 18:05:38)

It was a 0.7ma adapter. This is the 612 Modem I got from eBay so I could hack it.

I'm now using a 12v 1A adapter from the talktalk HG533 Modem/router as I do not use that router.

Is till have the ECI modem and power adapter that the engineer installed but its in a box somewhere.

The modem is just slightly warm to the touch and is drawing around 7w from the wall so thats all fine.

Edited by Seansmit17 (Thu 16-Oct-14 19:16:35)

The Huawei ones with the black power adapter should be swapped out because of a known overheating problem. If memory serves me right the new one should have 3B on the bottom with a white PSU.

Post deleted by rogerfp

Put it this way, I have a lot of this power adapters powering all sorts around the house. And not once in all my life has one blown like this.

So yes it is a serious question. Something like this could easily catch fire.

I'm so sorry that my concern is bothering you.

In reply to a post by pcoventry76:

I had an iphone charger blow up as I was pulling it out. It put me in Hospital for a week with burns and dysrhythmia.

abnormality in a physiological rhythm, especially in the activity of the brain

Hoping you get well soon pcoventry76....

Morning MHC

I don't know the details of today's switched-mode supplies; and to what extent the actual switching component is protected from Mains Spikes - any ideas?

====================

Switched-Mode Adaptors always remind me in principle, of the ancient Vibrator Power Supplies used with Car Radios in the late 1930s particularly, where a vibrating reed similar to an electric bell of the era, supplied a "square-wave" 12 V (or 6 Volts back then) DC to the Primary of a Step-Up Transformer, to achieve around 120 V DC after Rectification and Smoothing, to supply the HT required for the Valves/Tubes.

Edited by deleted (Fri 17-Oct-14 10:05:05)

Not by much!

A basic description:

Mains input between say 100 and 250v at 50 or 60Hz is fed into a bridge rectifier and a smoothing capacitor. That produces a very rough un-smooth DC at 150v or above. This DC is then switched on and off by a transistor at high frequency and varying duty cycle. The output may then pass through a transformer and is then rectified again and fully smoothed. This output is monitored by the controller chip which then varies the switching frequency and duty cycle control to the switching transistor.

So, not much at all.

In reply to a post by b4dger:

I bought a backup OR ECI modem and power supply from the Kelly engineer that installed my FTTC. Might have been £15 I didn't need to spend.

My Kelly engineer was so excited that I'd got everything up and running without a modem before he even came in he never gave me the modem. He's probably now sold it to someone for about £15

Thanks, MHC.

Very similar to the old Vibrators!

I think I know where a lot of eBay stock comes from!

I had to wrestle my old ADSLNation faceplate splitter off him - I guess he had a plan for that as well...

In reply to a post by eckiedoo:

Switched-Mode Adaptors always remind me in principle, of the ancient Vibrator Power Supplies used with Car Radios in the late 1930s particularly, where a vibrating reed similar to an electric bell of the era, supplied a "square-wave" 12 V (or 6 Volts back then) DC to the Primary of a Step-Up Transformer, to achieve around 120 V DC after Rectification and Smoothing, to supply the HT required for the Valves/Tubes.

They were still around in the late 50's.

I remember my parents had a car which, when the radio was turned on produced a loud buzzing noise and took a while to work (the valves had to warm up).

It was a great mystery to us until I learned how things work at school and wondered how the obviously valve operated device managed to work on 12V DC.

When I was about 13 or 14 it became obvious but inverters weren't exactly common place and this was the time when semi-conductors were becoming common.

Hi Seansmit17,

I'm sorry to hear you experienced this problem. We are interested to look into this in more depth with you and take any action necessary to put this right.

I understand you're registered on the TalkTalk Community. Can you post the above in a new thread on the TalkTalk Community, so we can get some more information from you to help us investigate. Once you've posted, please drop me (OCE_Mark) a Private Message there, to let me know, and I can pick up your thread.

Cheers

Mark
Online Community
TalkTalk

Done

Hmmm .

What are you hoping they are going to be able to prevent, when the problem was a (possibly duff) piece of kit that you bought on eBay? It's nothing to do with TalkTalk.

I assume the TT person just read your opening post, not the rest of the thread where this came out.

By the way, does the modem say 3B in large characters on the label underneath?

Its still an OR modem, regardless of where I got it from.. but meh.

As for the 3B.. its a 2B

What is its power rating on the label?

Which raises a question I've had for a while... I see people say things like 'Make sure you get the white plug/adapter to use with the OR modem'

Meanwhile, I see some of them connected to black power supply units.

So did they use to launch with black PSUs and now come with white or is this a third party supplier issue?

The originals that ended to overheat and fail, (the modem not the power supply), came with a 0.7w black one. The revised version, the 3B, comes with a 1w white one.

My original is now in the loft so I can't check easily. The 3B modem says 12v 1A.

So what I'm trying to discover from Sean is what his 2B requires. If 1A it could explain his black one failing.

In reply to a post by RobertoS:

The originals that ended to overheat and fail, (the modem not the power supply), came with a 0.7w black one. The revised version, the 3B, comes with a 1w white one.

My original is now in the loft so I can't check easily. The 3B modem says 12v 1A.

So what I'm trying to discover from Sean is what his 2B requires. If 1A it could explain his black one failing.

I use these for modem and router, plenty of headroom.

http://cpc.farnell.com/ideal-power/25hk-aj-120a200-c...

The modem I am using is 2B rated for 12v @ 0.7ma. Im using a 12v 1A AC adapter at the moment, the one that blew was 12v @ 0.7ma

So that shouldn't have been a problem. Just one of those things I think - things do fail.

In reply to a post by Seansmit17:

So I unplugged it and noticed that's where the smell was coming from. Got another 12v 1A adapter and plugged that in, all working.

Well, today, totally unsolicited, BT Openreach/PlusNet sent me a new PSU for my FTTC modem.

The old black one has been working fine for over 4 years, but I received a new white one for 'safety reasons', and was told to return the old one (although there's nothing in the attached documentation to indicate how anybody will know the old PSU has come from me !)