python program. apple asking machine

I've been trying to create a trouble shooting system any my code works fine in the begging but i can't seem to find the problem as it stops working.

    print("welcome to Apple online iPhone help system, I will ask you a series of questions and please answer with a 'yes' or 'no', if by the end our automatic troubleshooting system does not help you,there are more support and help options available on our website http://ift.tt/17k3gb1 ") 
q1 = input("Is your phone running slow?")
if q1 == "yes" :
        print("ou need to free up space, phones slow down when they are full, try deleting unused apps or unnecessary photos or buy more storage. If that doesn’t fix your problem contact Apple for more help.")

if q1== "no":
                print("okay let's move on to the next question")
                q2 = input ("have your dropped your phone in water?")
                if q2 == "yes":
                            print ("turn off your phone and leave your phone in a bag of rice for 72 hours and after the waiting periodturn it on and it should work, if it doesn't your phone is broken, contact apple to get it fixed")

                            if q2 == "no":# after this code it stops working i do not understand why.
                                    print ("okay let's move on to the next question")
                                    q3 = input ("Does your phone keep crashing?")
                                    if q3 == "yes":
                                                print ("Reset your phone and that should prevent your phone from crashing, If that doesn’t fix your problem contact Apple for more help.")
                                                if q3 == "no":
                                                        print("okay let's move on to the next question")
                                                        q4 = input("is your promblem due to the recent update?")
                                                        if q4 == "yes":
                                                                    print ("there could be multiple soulitions to the this problem, go to 'http://ift.tt/2liKHUX and find your problem")
                                                                    if q4 == "no":
                                                                            print ("okay let's move on to the next question")

---

when i run the program this happens

welcome to Apple online iPhone help system, I will ask you a series of questions and please answer with a 'yes' or 'no', if by the end our automatic troubleshooting system does not help you,there are more support and help options available on our website http://ift.tt/17k3gb1 
Is your phone running slow?no
okay let's move on to the next question
have your dropped your phone in water?no

it doesn't ask the next question why?