Slow Internet - CM500 Error Log Critial Issues

[ChaseEm]

Hello, we have noticed a steep drop off in our internet speeds which began a couple weeks ago. Additionally, on at least 2 occasions, the modem appeared to restart (or crash?) on its own and took about 30 min to get back online.

I have a Netgear CM 500 modem that I have paired with a TP-Link Archer C50 router. Internet is provided by Xfinity (Comcast). We’re signed up for “speeds up to 100 Mbps,” however recent speed tests show our download speeds in the low teens and single digits, and upload speeds in the low single digits. I had an Xfinity tech come out to check the cable connections, and he said everything looked good on their end, and that the modem was likely to blame. After he left, I found the modem event log (see screenshot) and it’s showing almost constant “Critical” errors. Is there something I can do to resolve these errors, or do I need to get new hardware? Both modem and router are about 15 months old, had Xfinity the whole time with no real issues until about 2 weeks ago. Coax cable goes right from the wall to the modem, I’ve tightened everything I can and the modem/router have been restarted many times over the past couple weeks.

Hardware version: C312T00-01

Firmware version: V1.01.12

Thanks!

[plemans]

do you have a screen snip of the modem cable connection page? it shows the connection back to the isp. 

[ChaseEm]

@plemansSee attached for Cable Connection screenshot

[plemans]

so you're caught in a catch-22 because the xfinity guy's already said the lines good.

your power fluctuates quite a bit and you have a lot of t3 errors. Which tend to point at the line. But since he's arlready been out and said its your modem, you're kind of stuck.

options? 

1. get someone else to check the line

2. replace the modem and if you still have the issues, then they need to recheck the line. 

3. rent one of their modems. they tend to rent out docsis 3.1 devices which can be a bit more tolerant of power flucations.