Yes, the power adapter from a modem-router might affect upload speed.
Yes, the power adapter from a modem-router might affect upload speed.
Could the power adapter of a modem-router be responsible for the sudden slowdown? Edit: In recent weeks my upload speed dropped sharply to 66%, while download remained strong. I contacted my ISP, who said there was no signal issue but promised a technician visit. The technician opened the Technicolor TC7200 modem and noted only one of four upstream channels was active. He then remarked, “I don’t like this power adapter,” which surprised me. I wasn’t aware that could be the cause! Later, he replaced the adapter and changed the coaxial cable splitter. After testing, speeds returned to normal. Why would someone lie?
Unlikely to encounter situations where only part of a connection suffers damage. More common issues include unresponsive upload paths or throttling from service providers, bandwidth caps, or poor upstream connections. Could be related to the type of incoming signal—coaxial, DSL, fiber—or the specific modem and router being used.
I've experienced this too. One of my closest friends had an issue with his first 1000Mbit connection using coaxial cable. His internet would frequently drop packets and become unstable, especially between the power supply and the router. After replacing the power supply, everything worked properly.
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?
Based on previous issues with coax internet, I sometimes faced periods when channels stopped responding. The ISP had to send someone to replace filters at the utility pole or something similar. Affordable splitters can also lead to problems. I’d stick with the adapter they provided and keep an eye on it to check if the issue returns. If it does, that gives the service team a clear reference point. Also, inspect the adapter labels for specs—if they match, it’s likely just a technician’s judgment. Regardless, don’t dispute the outcome since the channels are now working; focus on confirming the fix remains stable.
When issues arise from several causes, it’s helpful to spend time investigating each one individually and rechecking until the problem is resolved. This process requires patience. Alternatively, you can follow the technician’s approach and tackle all factors simultaneously, hoping for a quicker fix. You may not always pinpoint the exact cause, but the solution was achieved efficiently. I’m not defending the technician’s method, yet his approach likely saved time and reduced costs compared to digging deeper.
More power supplies degrade over time, making replacement a smart choice if they’re several years old. It helps postpone the need for a full PSU failure callout. There’s also a chance the PSU is only handling the load well; if it’s under strain, it could lead to intermittent problems. After a reboot it might seem fine, but issues could reappear later.