I have weird thing going on with Phantom 3 Standard (P3S).

Transmitter power led is staying Red.
I can start and fly. camera moves also.

no WiFi available.  When I try to reset the WiFi, transmitter power led rapidly flashes green/red and will not stop.  about 10 minutes later, transmitter start beeping.

Any idea?

Do I need new transmitter or replacement part?

You can fly the whole time the large LED is red ? And since you're not connecting to wifi there's no FPV image ?

Your phone's WiFi module is the culprit. To increase its range, use a WiFi booster Android app.

Phone's WiFi shouldn't be a problem.  
Since i can connect to my router 30 ft away.

It appears to be the transmitter"s WiFi is not working or broadcating its SSID..

All conteol works. Quad has solid red front LED. Yellow blinking LED which is ready to fly without GPS.

Transmitter LED satying Solid Red is something that I could not find.  It  is not charging status since it is not connected to charge.

You could control the aircraft with the remote even through it show solid red?
After reset the WiFi, you have tried different mobile devices, no phnatom WiFi available in the list, right?
If so, it's recommended to send it in for further evaluation and get it fixed, you could contact our tech support at support@dji.com for further help.

I got it to work.
now it is solid.
Looks like the transmitter has internal check like boot test.