Can Airport Express extend wi-fi from a non-Apple router? /// Airport Extreme wi-fi problem

[FlyingToasterStrudel]

Hi. I've done a search of this forum, but I haven't found a definitive answer to this question. I hope someone can help.

From time to time, every few weeks, the wi-fi network provided by my Airport Extreme (2nd gen) goes kaput, requiring a restart to set it right. (I never had this problem with the Time Capsule (1st gen) I used previously.) To be clear: the wi-fi network is still "there," and all devices are still apparently connected to it, and the light is still green, but no network traffic takes place. I haven't done troubleshooting to see if Ethernet connections still work; but that wouldn't help me much in any case.

I've tried doing a factory reset of the Airport Extreme, but the problem still persists.

So—assuming that this wi-fi issue is not easily fixable: I wonder if I can take my Airport Extreme out of the equation, while still getting the benefits of my Airport Express.

Here's my home network set-up:

Router from our cable ISP

• in bridge mode

Airport Extreme 802.11n (2nd gen) (2007)

• upper level of house
• connected directly to ISP router via Ethernet
• firmware: 7.8.1 (latest)
• used for:
  • providing a wi-fi network (2.4 GHz)

Airport Express 802.11n (2nd gen) (2012)

• lower level of house
• firmware: 7.8.1 (latest)
• (too far away to feasibly connect via Ethernet)
• used for:
  • extending the 2.4 GHz network; otherwise signal is too weak in the lower level of our house
  • providing a 5 GHz network; used for all working-from-home devices
  • AirPlay of audio to connected speakers

Apple TV (3rd gen)

• AirPlay via wi-fi

If I take the Airport Extreme out of the equation, and instead use my ISP router to create the wi-fi network, can I still use my Airport Express for any or all of the three functions listed above?

Thanks for any guidance.

 

[Ray2]

My AEX's work fine with the Amplify HD's (2) I replaced my extreme with. I'm wired from the base HD to all other network devices. I cannot recommend the HD's. Little to no improvement over my old Extreme based network. They started out with a lot of buzz. Now they don't seem to rate even an entry to comparison tests.

 

[FlyingToasterStrudel]

(BUMP...)

Can anyone else provide some advice for my situation?

TL/DR: If I were to retire my Airport Extreme, and instead use my ISP's router to supply the household network, taking it out of "bridge" mode, would I still be able to use my Airport Express for any of the following, as I do now?—

• extending the router's wi-fi network
• providing an additional network (dual-band functionality)
• an AirPlay target (will the Express still show up in the AirPlay menus?)

Thank you for any help.