Could a modem-router's power adapter be the cause of reduced upload speed?

[Noob3000]

Could a modem-router's power adapter be the cause of a sudden drop in upload speed?

Edit: Context

 

In the past few weeks i had 66% reduced upload speed and the download speed was maximum.
I called my ISP and the operator said that he doesn't see any problem with the signal but will send a team anyway to check the problem.

The guy arrived, oppened the modem-router Technicolor TC7200.20 WiFi address and said that only 1 of 4 Upstream Channels is active and after that he said:
„i don't like this power adapter“

Me: I had no idea that could be the problem!?
Him: Yup... you can't put battery from a Fiat 500 in a Mercedes.“
He got a new one and also without saying anything he changed the coaxial cable splitter.
He tested the speed and it was fine.
„See? It was the power adapter. Now all 4 upstream channels are active.“

Now i pluged-in the old adapter and the speed is still fine.
Why he would lie to me?

[191x7]

7 minutes ago, Noob3000 said:

Could a modem-router's power adapter be the cause of a sudden drop in upload speed?

Not really, no.

[PineyCreek]

Can't think of any scenario where a loss or surge of power would selectively damage one facet of a connection.  More likely to be an unresponsive upload channel or throttling from the ISP or bandwidth limitations upstream (or a crap connection to begin with).  What kind of incoming signal media (coax, DSL, fiber)?  What model modem/router?

[BetteBalterZen]

Actually yeah sort of. I've seen it myself. 

One of my best mates, when he got his first 1000mbit connection Coax, his internet would drop packages most of the time, was very unstable, it was the PSU to the router. He got a new PSU and then everything was fine. 

[Noob3000]

1 hour ago, PineyCreek said:

Can't think of any scenario where a loss or surge of power would selectively damage one facet of a connection.  More likely to be an unresponsive upload channel or throttling from the ISP or bandwidth limitations upstream (or a crap connection to begin with).  What kind of incoming signal media (coax, DSL, fiber)?  What model modem/router?

It is coax.
In the past few weeks i had 66% reduced upload speed and the download speed was maximum.
I called my ISP and the operator said that he doesn't see any problem with the signal but will send a team anyway to check the problem.

The guy arrived, oppened the modem-router Technicolor TC7200.20 WiFi address and said that only 1 of 4 Upstream Channels is active and after that he said:
„i don't like this power adapter“

Me: I had no idea that could be the problem!?
Him: Yup... you can't put battery from Fiat 500 into a Mercedes.“
He got a new one and also without saying anything he changed the coaxial cable splitter.
He tested the speed and it was fine.
„See? It was the power adapter. Now all 4 upstream channels are active.“

Now i pluged-in the old adapter and the speed is still fine.
Why he would lie to me?

[PineyCreek]

On 11/10/2022 at 6:59 AM, Noob3000 said:

It is coax.
In the past few weeks i had 66% reduced upload speed and the download speed was maximum.
I called my ISP and the operator said that he doesn't see any problem with the signal but will send a team anyway to check the problem.

The guy arrived, oppened the modem-router Technicolor TC7200.20 WiFi address and said that only 1 of 4 Upstream Channels is active and after that he said:
„i don't like this power adapter“

Me: I had no idea that could be the problem!?
Him: Yup... you can't put battery from Fiat 500 into a Mercedes.“
He got a new one and also without saying anything he changed the coaxial cable splitter.
He tested the speed and it was fine.
„See? It was the power adapter. Now all 4 upstream channels are active.“

Now i pluged-in the old adapter and the speed is still fine.
Why he would lie to me?

From past experience when I had coax Internet, I also had up channels periodically not responding.  The ISP had to send someone to swap out filters on the line or something at the utility pole outside.  Cheap coax splitters can also cause some issues as well.  I'd stick with what they gave you (the new adapter) and monitor it to see if it reoccurs.  If it does, there's another datapoint for the service personnel and technical support.  You should also be able to look at the labels on each adapter and see what the specifications are.  If they're the same specification, then it's a subjective move (or experience) from the technician.  Either way, don't argue with results since the up channels are working now...just see if the fix sticks.

[Noob3000]

11 hours ago, PineyCreek said:

From past experience when I had coax Internet, I also had up channels periodically not responding.  The ISP had to send someone to swap out filters on the line or something at the utility pole outside.  Cheap coax splitters can also cause some issues as well.  I'd stick with what they gave you (the new adapter) and monitor it to see if it reoccurs.  If it does, there's another datapoint for the service personnel and technical support.  You should also be able to look at the labels on each adapter and see what the specifications are.  If they're the same specification, then it's a subjective move (or experience) from the technician.  Either way, don't argue with results since the up channels are working now...just see if the fix sticks.

I put back the old adapter and it works the same as with the new one. I guess it was the splitter..

[Falcon1986]

2 hours ago, Noob3000 said:

I put back the old adapter and it works the same as with the new one. I guess it was the splitter..

If a particular problem can be due to multiple factors, you can take your time trying to fix each factor and retesting to see if the problem is fixed. That takes time.

 

Or you could do what the technician did and address all of the factors at once and hope something gets fixed. You might never know the exact factor but, at the end of the day, the problem was solved quickly.

 

I'm not trying to justify the technician's method, but his "fix" was likely faster than trying to find the root cause and more cost-effective.

[Alex Atkin UK]

3 hours ago, Falcon1986 said:

If a particular problem can be due to multiple factors, you can take your time trying to fix each factor and retesting to see if the problem is fixed. That takes time.

 

Or you could do what the technician did and address all of the factors at once and hope something gets fixed. You might never know the exact factor but, at the end of the day, the problem was solved quickly.

 

I'm not trying to justify the technician's method, but his "fix" was likely faster than trying to find the root cause and more cost-effective.

Plus PSUs do age, so its not a bad idea to replace it if its a few years old, it defers a callout for the PSU actually failing later.

 

Its also possible the PSU is marginal so could cause random issues, so while it works fine after a reboot, it might cause the problem again later.