ONT

So I live in the new forest and we are prone to the occasional power cut...... And when we do have power back on, the ont gracefully powers up with no flaff.

Tonight I decided to change the multi gang extension lead and in a moment of cba i just powered the old extension unit off which should have been fine but what happened when i powered it back was slightly different

five minutes of madness of no pon light and intermitent lan light and a very brief los light.

Should i check the ont power cable. Or should i just put it down to the olt deciding i can't join the party.

I'm more concerned about the brief 2s los light.

(i'm thinking out aloud here because its something i've never seen and my ont exposure like many equals one)

Well, it seems a bit odd …but if you are feeling brave, and can accept that it might be the ONT’s death throes you glimpsed … and you might be entering a world of no internet ball ache … power cycle the ONT again. Then watch carefully the light sequence as it powers back up. Or ….. you’ve killed it.

Your description of the light sequence doesn’t match anything I’ve seen. Hence thinking it seems iffy.

Good luck … keep the thread updated

Is there a massive Openreach ONT grave yard somewhere out there?

Have you by any chance got another 12v power supply with the same dimension barrel connector that you can try out?

If it’s the same outcome then ONT itself is probs kaput. Pretty tough things but they do misbehave and die from time to time…I had to have Zeus himself intervene and send down 100 million volts to kill my OG Huawei (backfeed via Ethernet port…you didn’t want to see the switch)😅🙈

i have a spare or ont psu.......

the or engineers left things ..........

Must’ve fallen out the back of the van as the engineer was driving away… 😅😂

yeah its a nokia 2.5gbit one.

normally its pwr, lan and then pon....... but tonight it was only pwr, and the lan going off and back on and then off (not the standard lan type flickering).

i will check the cable in the morning for any issues.

Even though the los light came on briefly for like 5s, it should not come on in normal conditions. I didn't touch the ont or the fibre cable.

In reply to a post by Pheasant:

Must’ve fallen out the back of the van as the engineer was driving away… 😅😂

the actual event was, the nokia 1gbit unit supplied, was blinking for 30 minutes when they installed it and the engineers gave up on it - they suggested a failed firmware update, the other engineer went to his van and grabed a 2.5gbit one.

They left the box the with failed ont .....

Mind you i like the back of the van theory 😂

In reply to a post by PCJM40:

Is there a massive Openreach ONT grave yard somewhere out there?

Yes quite a large one. It’s called eBay UK 🇬🇧 😂

are there still onts on sale on ebay......?

not looked for ages (don't make me look 😁😶👀)

In reply to a post by Taras:

In reply to a post by Pheasant:

Must’ve fallen out the back of the van as the engineer was driving away… 😅😂

the actual event was, the nokia 1gbit unit supplied, was blinking for 30 minutes when they installed it and the engineers gave up on it - they suggested a failed firmware update, the other engineer went to his van and grabed a 2.5gbit one.

They left the box the with failed ont .....

Mind you i like the back of the van theory 😂

We must get the the most thoughtful engineers. I asked them to reuse the old BBU housing etc for the upgraded Nokia so they left the new power supply too. Then I had an other spare from when they replaced the dying OG Huawei. Hmmm eBay may be calling…😂

It sounds like it was doing a firmware update

I could be wrong, but doesn't the pon light flash during fimware update..

Not sure how things are affecting if theres a olt firmware update

Power it off, for a full 5 mins (to allow capacitors to discharge).

Power it back on.

If it doesn't work, then contact your ISP to report a fault. End of story.

No point trying to swap to a "spare" ONT - it will have the wrong serial number and won't associate to the OLT for your service.

In reply to a post by candlerb:

No point trying to swap to a "spare" ONT - it will have the wrong serial number and won't associate to the OLT for your service.

yup i know that but its all good for the search engines. 😁

so an update.

Firstly i forgot to say that i had a power cut last week so i watched the ont power up normally.

But this morning i did a power off - wait a minute, and powered back on and it did:

pwr on
lan light on
then a brief 3s lan light off back on
pon light on

in about 56s which seems about right.. No los light ......

did tbb speed test last night and today - which seems about right for a 1gbit service..

Edited by Taras (Mon 07-Sep-26 08:25:15)

In reply to a post by Taras:

so an update.

Firstly i forgot to say that i had a power cut last week so i watched the ont power up normally.

But this morning i did a power off - wait a minute, and powered back on and it did:

pwr on
lan light on
then a brief 3s lan light off back on
pon light on

in about 56s which seems about right.. No los light ......

did tbb speed test last night and today - which seems about right for a 1gbit service..

Well that seems like good news.
There was a suggestion elsewhere that it might have been a software update …. which is a possible , though when the ONT’s I have met took an update (often on first switch on) I recall just the power light only staying on for a while, then the others coming back a while later…. no LOS light for sure.


Well let’s hope it was just a glitch.

yeah even i dissmissed it, a brief software update may have occured. given the updates i've seen on two onts (one duff) which took a while, dissming it was based on that experience - unfortunity thats what all anyone (customer of or) can do. Software updates may be quicker now and i would have no clue. so dissmissing it was a bit of a stupid comment to make by me

Hopefully what happened last night is a one off

In reply to a post by Taras:

five minutes of madness of no pon light and intermitent lan light and a very brief los light.

In reply to a post by Taras:

normally its pwr, lan and then pon....... but tonight it was only pwr, and the lan going off and back on and then off (not the standard lan type flickering).
...
Even though the los light came on briefly for like 5s, it should not come on in normal conditions. I didn't touch the ont or the fibre cable.

In reply to a post by Taras:

I could be wrong, but doesn't the pon light flash during fimware update..

I've never seen an Openreach ONT do a firmware update in the wild. But from the light sequence, it doesn't sound like it was...

According to the below the PON light should flash on boot up. Yours was off completely. Alarm (LOS) also shouldn't be coming on at all.

Light sequence for Nokia G-010G-T

I wish i had videoed the issue. As both the pon and lan came on and off.....I would have videoed it if had happened this morning on a test reboot.

it could have been some random thing, a negotaion failure or a firmware update. Thats partly why wrote the inital post the way i did. It really was like "what the fuzz did i just witness"

Alarm (LOS) also shouldn't be coming on at all.

There was a suggestion elsewhere that it might have been a software update …. which is a possible , though when the ONT’s I have met took an update (often on first switch on) I recall just the power light only staying on for a while, then the others coming back a while later…. no LOS light for sure.

I got one right !