Having issues with your signal is never fun but I can help you narrow in on the what is causing it. One of the first thing we need rule out is a known or reported mast issue(service outage) . The checker should give you details of any local issues, including planned work, as well as showing signal strength (2G, 3G & 4G) & outages.
There are two ways to identify a service outage:
❇️ An outage is identified in your area by the mast service checker here http://community.giffgaff.com/t5/Using-giffgaff/Force-the-change-of-SMS-settings/ta-p/4871794
knowlede base link on how to perform the manual roam.
Finally you can try turning off your device for a couple of minutes and back on again to see if that helps.
Also, Check if the SIM is faulty - If you have an error message on your handset (e.g. "SIM not recognised" or "SIM not valid") or if your SIM does not work when tried in another phone, do a standard SIM clean (which is just really giving the SIM card a wipe to ensure that there's no dirt on the card, being carefully not to scratch the gold chip).
Once you have cleaned your SIM, re-insert it into your phone. If you have activated successfully, your SIM should now be in full working order. If not, it is certainly faulty.
If your SIM is faulty, you will need to order another SIM. Order another SIM from your spread page here https://giffgaff.com/orders/mgm
and when the new SIM arrives perform a SIM swap.
Or Need a new SIM in a hurry? Giffgaff SIMS are now available to buy from local retailers e.g. Tesco, Poundland, Asda, Iceland etc – they are priced at around £1.00.
And to make life easy, giffgaff are now sending out triple SIMs which contain all 3 different sizes of SIMs in one. This means that a single SIM can be used as a standard sized SIM (Standard), a Micro SIM and a Nano SIM. If you need to form the Nano or Micro size SIM simply push out the middle.
The SIM swap process will transfer your current number and allowances e.g. goodybag and/or airtime credit over to the new SIM. The process should take no more than 30 minutes to complete and can be performed anytime between 4.30am and 9.30pm
YouTube video Tutorial.