If you are sure about the test point, try to find the trouble before the test point.
Take care that the signal level on the IF path can change very much, depending on the field received.
About the capacitor, if you heat the capacitor and the phone is working means that the trouble is around there, change the capacitor.
The capacitor can be good after the heating only if before was a cold joint on one of the two terminals.
I have never seen a bad capacitor became good heating it !
The measurement following the levels reported on the service manual are valid only if the phone is connected on the test bench, otherwise can change very much.
Mandi