ATA HT801 died - Replacement also died

[Potato_Tomato]

Hello all, I hope everyone is doing well.

I would like to provide some context first:
- I have used Fongo Home Phone since April 2025.
- Fongo have confirmed that my account is active and there are no restrictions that could be causing the service functionalities to be disrupted.
- My ISP is Bell. My Modem is Bell Home Hub 4000

TL;DR: ATA HT801 died in less than a year. Fongo sent ATA HT802 V2, and it works for 30 minutes, then also died in the exact same manner of the first one.

Detail Below:

A few weeks ago, my Grandstream HT801 suddenly stopped working, with the message "Check Tel Line" on my Fongo Home Phone. The power light of the ATA stay on, but the Ethernet and Phone lights stay off. On the Ethernet ports of both the ATA and the Modem, there is no blinking green and orange light.

Naturally, I did all the basic troubleshooting steps:

- Using different 3 different sets of Ethernet Cables to test the connection between the ATA and the Modem.
- Try plugin to other LAN Ethernet ports on the Home Hub 4000.
- Try different different phone cable (rj11).
- Try to power down both my Modem and the ATA for 5 minutes, then reconnect them one by one following Fongo setup instruction.
- After all of the above failed to resolve the issue, I used the reset button on the back of the ATA device. However, it seems the reset button does not do anything. I user a paperclip, pressed the reset button, heard the "click" sound, and hold it for like 20s. But the power light stay on the entire time.

Eventually, I contacted Fongo support, and they sent me a new ATA, this time, it is the Grandstream ATA HT802 V2.

Once again, I follow the exact same instruction from Fongo to setup the new ATA, and it worked. I could dial a call, and receiving call. But 30 minutes later, I tested again and everything stop working...no dial tone, nothing work.

I check, and literally it is the same issue with the previous ATA: only power light is on, every other lights are off. No blinking lights coming from the Ethernet port of both the ATA and Modem.

I went through the basic troubleshooting steps again as mentioned above, but adding one more step where I use a USB plug with the output of 5V - 1A to provide power to the ATA (matching the output of the power adapter the comes with the ATA), but this also does not resolve the problem.

I login to my Bell Modem, and it said there are only 3 devices connecting to the LAN Ethernet Ports, they are all 3 PCs I have. The Modem does not register the existence of the ATA at all.

I called Bell and they confirmed that they did not block anything, and everything look good from their side.

I am going through Fongo support again in the meantime, but for now, I am at lost...what could possibly cause this issue. I am thinking power related issue? Something with voltage, surge, etc? There is no power outrage in my area for the last few weeks, and no thunderstorm or lightning strike.

Both my Modem and the ATA are plugged in to a Surge Protected Power Strip.

I attached some of the pictures of my setup in this post also.

I am tempted to buy another HT802 V2 on Amazon to test, but I don't think that will work with Fongo, since they may have custom firmware and what not.

Any support or helps are much appreciated.

[Liptonbrisk]

On the Ethernet ports of both the ATA and the Modem, there is no blinking green and orange light.

No blinking lights coming from the Ethernet port of both the ATA and Modem.

If there's no Ethernet link lights on either the ATA or the Home Hub port, that means there’s no Layer‑1 link at all.

Even if the adapter label says 5V/1A, a bad supply, loose barrel/USB connector, or a power strip doing something odd can let the unit boot and then brown‑out, leaving it half alive (power LED is on but with an Ethernet PHY issue).​​

Two ATAs failing the same way could mean an environmental electrical issue (electrostatic discharge, bad grounding, a problematic power strip), or possibly a bad batch of power supplies.

Try plugging the ATA's power supply straight into a wall outlet, and retest for link lights. Do that briefly (quick test); I don't like plugging in electronics directly to unprotected wall outlets. Also unplug all ethernet cables from the Hub, except for the ATA's while testing (try the first LAN port while all other ethernet cords are unplugged).

There is no power outrage in my area for the last few weeks

A neighbour believes the exact same thing (granted, most people probably don't pay attention). However, there's not a week that goes by where the hydro on my street doesn't drop for at least a second. My battery backups are kicking in every single week. I'm not exaggerating; it's ridiculous.

I'm surprised my whole home surge suppressor doesn't need to be replaced yet.

I attached some of the pictures of my setup in this post also.

What does the phone cord from the ATA plug into exactly? That's an important question.

This isn't related to your problem, but disable SIP ALG in your Bell Hub.
Open your web browser, and login at 192.168.2.1 with your administration password. You can also try logging in at bell.ca/mymodem
Navigate to "Advanced tools & settings"-->"Networking"
Disable "SIP ALG".
Someone posted a screenshot: https://forum.bell.ca/t5/Internet/Home- ... td-p/11830.

I would also consider disabling UPnP, but that's another conversation (and completely unrelated).

I am tempted to buy another HT802 V2 on Amazon to test, but I don't think that will work with Fongo

It won't. Your ATA must be supplied from Fongo.

[Potato_Tomato]

This isn't related to your problem, but disable SIP ALG in your Bell Hub:

I can confirm that SIP ALG has been disabled a long while ago.

What does the phone cord from the ATA plug into exactly?

It connects to the Panasonic DECT 6.0 2-in-1 Corded/Cordless Phone - KX-TGF870CB

Two ATAs failing the same way could mean an environmental electrical issue

Could you please recommend some kind of mini UPS / Surge Protector with battery backups? Due to spacing issue and the location of the Modem and the ATA device, I cannot invest into a huge UPS

[Liptonbrisk]

It connects to the Panasonic DECT 6.0 2-in-1 Corded/Cordless Phone - KX-TGF870CB

Okay, that rules out my speculation about electricity from a wall's phone jack feeding into the ATA and wrecking it.

Try plugging the ATA's power supply straight into a wall outlet, and retest for link lights. Do that briefly (quick test); I don't like plugging in electronics directly to unprotected wall outlets. Also unplug all ethernet cables from the Hub, except for the ATA's while testing (try the first LAN port while all other ethernet cords are unplugged).

Could you please recommend some kind of mini UPS / Surge Protector with battery backups?

I'm not the best person to ask. APC BE425M is one option. If that's too big, then, unfortunately . . . I'm not a good a person to ask.
I would plug only the Home Hub 4000, ATA, and (if needed) the phone base into the battery-backed outlets.

[Potato_Tomato]

Try plugging the ATA's power supply straight into a wall outlet, and retest for link lights. Do that briefly (quick test); I don't like plugging in electronics directly to unprotected wall outlets. Also unplug all ethernet cables from the Hub, except for the ATA's while testing (try the first LAN port while all other ethernet cords are unplugged).

I just tried this with 2 power adapters that come with the first and second ATA. Then also tried using a separated USB power adapter.

Disconnected all Ethernet cable from the Modem, then try each port one by one.

Nothing happen, still only Power Light on.

I also tried to use the reset button at the end, it also does not do anything

[Potato_Tomato]

If power surge is the issue, I assume the ATA device must be super sensitive? Since the Bell Modem also connect to the same power strip, and it is working just fine.

[Liptonbrisk]

Okay. While I'm not entirely sure, since there's no Ethernet link LEDs on either end, and resetting the ATA does nothing, it seems plausible to me that the ATA hardware is damaged (or stuck), as opposed to anything SIP or NAT-related.

Grandstream’s guide says that when an HT801/HT802 is ready, “Power, Ethernet, and Phone LEDs will be solidly lit". If the Internet/Ethernet LED is off, that indicates the adapter is not connected to the network at the physical/link level.

I would consider a damaging event or abnormal mains/grounding (spike/surge, neutral/ground fault) that these small adapter/ATAs didn’t survive, or a flaky connector is causing repeated brown-out cycles that eventually killed them. The pattern (two different models, same failure) suggests an environmental electrical stressor better than SIP settings.

The only electrical entry points to the ATA are from the power supply, a phone port, and an ethernet cable.

Your updated info (ATA phone port goes only to the Panasonic DECT base and not house wiring) makes classic PSTN electrical backfeed extremely unlikely. I suppose a faulty powered phone base or its power supply could still inject foreign voltage, but I've never heard of that happening (then again, I'm not an electrician or an expert). I have to believe electrical problems coming from a Panasonic DECT phone base are uncommon (but I'm not an expert).

What happens if you unplug the phone cord from the ATA? I'm guessing there's no change in the Ethernet LEDs?

The ethernet path seems also unlikely to me (maybe possible). Standard IEEE PoE generally won’t energize a non‑PoE device. However, passive or non‑compliant PoE gear can put voltage on the line continuously and can damage non‑PoE devices. That would only be relevant if there’s any PoE injector/switch or powered wall jack involved. And I don't see that in your configuration.

I would lean towards an electrical issue or bad luck running into units that die quickly.

[Liptonbrisk]

If power surge is the issue, I assume the ATA device must be super sensitive? Since the Bell Modem also connect to the same power strip, and it is working just fine.

In my experience (although I don't typically use Grandstream ATAs), the power supplies for ATAs usually fail before the ATAs do.

Different devices have different levels of surge tolerance and internal protection circuitry. Even when plugged into the same power strip, two devices can experience the same electrical event very differently depending on their power supply design and component quality. Additionally, damage can enter through multiple conductive paths including AC power, Ethernet cabling, or the phone line, so the fact that they share a power strip doesn't mean they're experiencing identical electrical stress.

Plug‑in surge strips clamp at a rated let‑through level (UL 1449 tiers, such as 330/400/500/600 V for example), meaning some surge voltage still reaches the connected devices. Smaller repeated surges can degrade components over time. So a device may fail later even though other gear seems fine.

If the ATA repeatedly ends up in a power LED-only state (no Ethernet link with resets not doing anything), I’d lean towards an actual hardware failure, and I would focus on isolating which electrical path is causing the problem: try the next ATA on a different outlet/circuit, run the ATA with power and Ethernet only (no phone cord) for an hour, and then try adding a phone.

I would also consider using a UPS.

[Potato_Tomato]

What happens if you unplug the phone cord from the ATA? I'm guessing there's no change in the Ethernet LEDs?

Yep, same problem. Nothing changed.

I would lean towards an electrical issue or bad luck running into units that die quickly.

While I believe "Dead on Arrival" could be the potential issue, the fact that the replacement did work for like 30m, then died, make leans toward to electrical issue.

Fongo just replied that they will send another replacement. I will invest into a UPS and extra surge protector, and plugin to another circuit to test first. Probably calling an electrician, too.

Thank you for your help and information. I have learned a lots today. I really appreciate it.

Have a good day!

[Liptonbrisk]

Fongo just replied that they will send another replacement. I will invest into a UPS and extra surge protector

UPS for the ATA is fine. You don't need an extra surge protector for it. The APC BE425M, for example, already provides surge protection on its outlets and battery backup on 4 of them. Plugging a surge strip into a UPS can cause issues with ground loops, overload the UPS's breaker unexpectedly, or create cascading protection failures. Plug device power adapters directly into the UPS outlets.

Thank you for your help and information. I have learned a lots today. I really appreciate it.

You're very welcome!

[Liptonbrisk]

The APC BE425M, for example, already provides surge protection on its outlets and battery backup on 4 of them

I will invest into a UPS

Oh wait. I don't really recommend APC BE425M because you can't easily replace the battery inside it. Once the battery dies, it becomes e-waste. See: I'm not a good person to ask for UPS recommendations.

You can replace the battery in an APC BE550G.

Cyberpower has EC550G and EC650LCD, which also have replaceable batteries.

I've not used any of the UPS models listed here.

[Potato_Tomato]

You can replace the battery in an APC BE550G.

Thank you for following up with your recommendation, but realistically speaking how likely the battery inside a UPS just die?

Nevertheless, I will try to find a compact UPS for sure, bonus if the battery is replaceable.

[Liptonbrisk]

Thank you for following up with your recommendation

Cyberpower has EC550G and EC650LCD, which also have replaceable batteries.

but realistically speaking how likely the battery inside a UPS just die?

The batteries do die, and they need to replaced when that happens.

Many small UPS units, such as the APC BE550G or CyberPower EC550G, use sealed lead‑acid batteries, and you should typically expect about 3 to 5 years of service life before the battery needs replacement under normal indoor conditions.

That number can be shorter (sometimes closer to 2–3 years) if the UPS is kept warm, frequently discharges, or sits in poor power conditions, and it can be closer to the high end if it’s kept cool and rarely has to run on battery. APC’s own guidance for their UPS batteries is also in the three to five years range, and CyberPower gives the same general expectation for UPS batteries.

That's for sealed lead-acid batteries.

There's also lithium UPS batteries, but those models usually cost more upfront.

[Potato_Tomato]

On the topic of UPS, I just learn about Standby vs Line Interactive UPS. From Google AI:

Standby (Offline) UPS offers basic, low-cost battery backup for non-sensitive electronics, switching to battery during outages with a 2-10ms delay. Line-Interactive UPS provides better protection by adding Automatic Voltage Regulation (AVR) to correct brownouts/surges without using the battery, making it ideal for workstations and network gear.

So, If I understand this correctly, Standby will only work for scenario where there is power outage. Outside of that, it does not do much.

Line-Interactive UPS to protect my devices from surge and power fluctuation (the issue I potentially having currently), even when there is no power outage.

[Liptonbrisk]

Standby will only work for scenario where there is power outage

Not exactly, no. Even a basic standby (offline) UPS will switch to battery if the voltage sags far enough, not just when it drops cleanly to zero. The distinction is more about how and when it deals with bad voltage, not whether it ignores sags entirely.

The key difference between standby and line‑interactive is not that one only works in outages and the other works all the time, but rather how they respond to different amounts/severities of bad power.

A standby (offline) UPS passes utility power straight through during normal operation, with built‑in surge suppression and some filtering. It monitors the input, and if voltage falls outside a defined acceptable window (too low, for example), it transfers to battery after a short delay measured in milliseconds. That means the UPS kicks in during a sag, but only once the sag crosses its definied threshold.

A line‑interactive UPS does the same basic monitoring but adds Automatic Voltage Regulation. Instead of immediately jumping to battery when voltage drifts low or high, it can boost or trim the voltage while still running from mains, only switching to battery when conditions exceed what AVR can correct. This lets it handle a broader range of brownouts and mild overvoltage events without hammering the battery, which is why it’s usually recommended for network gear and workstations in areas with frequent fluctuations.

The reason people suggest line‑interactive for dirty power is that it can smooth out a wider range of voltage swings using AVR before resorting to the battery, which is better for both uptime and battery longevity if your problem is frequent brownouts rather than just the occasional blackout.

But it's not as though a regular UPS will never kick in when voltage sags (house lights flicker, for example, but a sealed lead acid battery can still provide power properly to the ATA).

[Liptonbrisk]

But it's not as though a regular UPS won't kick in when voltage sags (house lights flicker, but a sealed lead acid battery can still provide power properly to the ATA).

A basic standby/regular UPS will still protect the ATA during a deep sag. If the house lights are visibly flickering because voltage has dropped enough, the UPS’s input monitor will usually see that as being out of tolerance and switch to the SLA (sealed lead acid) battery, so the ATA keeps seeing a stable output. From the ATA’s point of view, it doesn’t care whether the UPS is correcting with AVR or fully running on battery; it just sees reasonably clean voltage.

The distinction is more about when the UPS decides to jump to battery and how it handles smaller, chronic undervoltage. A standby unit has a narrower acceptable band: anything inside that band goes straight through, anything outside it triggers a transfer to battery. A line‑interactive unit widens that band by using AVR to boost or trim first, then falls back to battery only when AVR can’t cope. In lots of minor, frequent sags and swells that fall between what's acceptable and battery usage, a line‑interactive unit will actively nudge the voltage back toward nominal without constantly cycling the battery.

[Potato_Tomato]

I see, so a basic Standby UPS should be more than adequate then.

Thank you so much again for your time and input. I will post an update once I am able to investigate and setup everything again, with extra protection this time

[Liptonbrisk]

I see, so a basic Standby UPS should be more than adequate then.

There's some nuance here.

If your mains power is not reasonably stable—if you’re seeing frequent brownouts, lights dimming regularly, or voltage swings that are stressing equipment—a line-interactive UPS is the better choice. In that situation, a standby UPS would likely be switching to battery constantly to correct those frequent sags, which accelerates battery wear and reduces runtime for a real outage. A line-interactive UPS uses AVR to handle that same range of marginal voltage while staying on mains, so the battery stays healthier (theoretically) and you have more capacity left for when the power actually drops out.

Frequent cycling also means the standby unit’s transfer delay (even if only a few milliseconds) to battery happens more often, which could be enough to cause brief glitches or reboots on sensitive gear, such as an ATA (I'm not using your Grandstream ATA model). A line-interactive unit also tends to have a wider input voltage tolerance before it needs to intervene. There's a smoother transfer to stable power.

I'm mostly concerned with pushing you to spend more than you need. However, if you're constantly seeing lights flickering, daily, for example (as opposed to maybe once a week for a very brief period), I would lean more towards line interactive.

Anyway, again, I'm not an expert.

[Potato_Tomato]

So, my entire office room has like 5 wall outlets, all running on one single line of power (as in, they all share a single breaker in the main breaker box).

Granted, even my office room is packed with electrical devices, I rarely, if not never experience light flickering, dimming, or brownout, both in summer, or winter (2 laptops, 2 PCs, many peripherals, treadmill, air purifier, the modem, the ATA, lights, Portable AC in the summer, etc.)

Albeit, if a single power line support ~1650w (110V * 15A), my office is probably on a heavier side of power usage, maybe close in reaching the max limit...I do not know if that could potentially affect the power outlet for the ATA and the Modem.