[R-390] Off-topic: Help!

[wli]

I'd like to make a quick off-topic request of this group.... please reply your suggestions directly to me at wli98122 at yahoo.com, so as to not contaminate this listserv
Problem: my son has two separate garage doors. Neither one will open using its dedicated remotes in the cars or in the separate hand-helds..... even after I have replaced all batteries, swapping remotes with other known good ones etc ,,,, yet the wired controls for both doors do operate normally.  Is it possible that something/some-one outside my property is causing this wireless loss?  Could both door receivers fail at the same time? not likely staistically. SInce both receivers and both door motors are on the same AC circuit... could a "dirty" AC line cause this problem?  In desperation, he added a WiFi door opener, and even its operation is intermittent.  Thanks to all in advance    W. Li  (ex-Pearls guy)