topic Re: Alarm reset on Openreach ONT in Broadband

Alarm reset on Openreach ONT

DiDi1 — Tue, 04 Feb 2025 14:56:20 GMT

Due to a very short power interruption yesterday the alarm indicator on my Openreach ONT is red. All other lights are green as are those on my router. Internet is working fine, how do I reset the alarm indicator to green?. I have switched off/on both the ONT and router but this hasn't made a difference.

Re: Alarm reset on Openreach ONT

Chrisee — Tue, 04 Feb 2025 15:09:19 GMT

@DiDi1 the lights vary between ONT types but It is probably an alarm for the battery back up which some older units had which is now redundant see this thread for more information.

Re: Alarm reset on Openreach ONT

DiDi1 — Tue, 04 Feb 2025 15:14:05 GMT

Thanks for this but my ONT was only fitted in December last year.

Re: Alarm reset on Openreach ONT

Chrisee — Tue, 04 Feb 2025 15:18:32 GMT

@DiDi1 can you post a picture as none of the models on the Sky help page have an Alarm light see https://www.sky.com/help/articles/optical-network-terminal

Re: Alarm reset on Openreach ONT

TimmyBGood — Tue, 04 Feb 2025 15:43:36 GMT

@Chrisee

There's a 2024 model which does: that Sky page is a bit out of date.

Re: Alarm reset on Openreach ONT

Chrisee — Tue, 04 Feb 2025 15:54:58 GMT

@TimmyBGood OK that looks like an Adtran unit. @DiDi1 if that is your unit from looking online the alarm light means there can be an issue with the firmware. If its working Inwouldn'tvworry too much but if it bugs you powering it down for a while say 30 minutes has cleared the light or is some cases it cleared in its own after a few days. In all cases I found the isp's position was its not broken sondoesnt need fixing.

Re: Alarm reset on Openreach ONT

Chrisee — Tue, 04 Feb 2025 16:01:49 GMT

@TimmyBGood as I know you like detail as much as I do 😉 I found the manual for the Adtran SDX611 here https://www.manualslib.com/manual/2238784/Adtran-Sdx-611-Gpon-Sfu-Ont.html?page=3 the alarm light inducates a firmware update failure so isnt critical.

Re: Alarm reset on Openreach ONT

TimmyBGood — Tue, 04 Feb 2025 16:10:05 GMT

@Chrisee

Such a particularly helpful way to label an LED too.

They really don't bother with consumer testing, do they?

Re: Alarm reset on Openreach ONT

Chrisee — Tue, 04 Feb 2025 16:25:18 GMT

@TimmyBGood bright red lights never mean anything scary do they?. On my last car the AC displayed a red led when operating in auto mode which bugged me for 5 years.