Bad lightning season here as well this year.
So four weeks ago, I lose cable after a really bad storm, and when the tech finally gets here, he finds it's that grounded MOCA filter in the outside box that's open. He replaced it and all is good.
Me, being paranoid (because I had to wait several days for a tech because so many people in the area took a hit), I covered my ass and ordered several spare MOCA filters, and the same 9 port MOCA amplifier Comcast installed, from Amazon, so I'd have spares.
A week ago I took another hit, and the MOCA filter fried again, so I replaced it and patted myself on the back.
Last night was another really bad storm, and we lost cable again. This took a while to diagnose this morning. I sure wish I could buy one of those fancy signal strength testers the Comcast techs use - it's basically a portable modem that links to their cell phone and gives them signal strength measurements, line condition, etc. (might have to do some inquiries - I'm sure someone sells them, but I bet they're pricey). Without a tester, it was trial and error: Bypass the filter, no joy. Bypass the amp and no joy. Bypass both the amp and the filter and bang, I've got signal. This time it was both the MOCA filter and the amp.
Being that it was a Sunday, and assuming I'd have to wait days for a service call, I just swapped them both out myself, and ordered another amp so I'd have a spare. Well worth the $70 to me to not wait for a service call.
I noticed the amp has a ground lug on it, which Comcast never seems to use, but to add some extra protection I went ahead and grounded the new amp. Can't hurt.
Might have to invest in one of those surge protectors myself. I'm also going to order an RJ45 surge protector to put between my modem and the gateway. I've used those in client's offices that were prone to lightning damage down the cable line. I'd rather not fry my expensive gateway and switch.
If anyone is interested, you can order the filters and the amp from Amazon here:
Amp:
https://www.amazon.com/gp/product/B07TN963JJ
Filter:
https://www.amazon.com/dp/B01C4SG4GE
FYI: As mentioned, you can bypass the MOCA filter with an F-fitting barrel just to see if that's the problem. Your cable will work fine without the filter, except you might have issues with your DVRs not seeing each other's recordings. MOCA is a local network over your house cable wiring that lets the boxes and other Comcast devices talk to each other, like sharing DVR recordings, and if you use Comcast's security cameras or alarm system, displaying the calling phone number on your screen, etc. The filter prevents those signals from leaving your house, or signals from another house from entering your network, and confusing the boxes. In a pinch you can bypass the filter, and just replace it whenever you can. It's just a filter that blocks signals over a certain frequency that's used by MOCA.
For this reason you also have to make sure your amp is a MOCA amp, that is specifically designed to pass MOCA signals. Regular antenna amps won't. Again, in a pinch you can always bypass the amp with a splitter, but you'll get less signal, so you may only be able to connect the modem and fewer of the boxes, but it'll get you going in a pinch if you don't have a spare amp.
The Comscope MOCA amp I linked to should work with any modern cable company. They all use MOCA now.