unlocking a phone that has been relocked to vodafone

[robgoch]

A phone (LG GT400) I got on monthly Vodafone contract 7 years ago was unlocked in Aug 2012. However, for reasons I can't fathom it has recently re-locked ! Powers up Vodafone flash screen, and refuses to recognise any other SIM (-I've tried Tesco, Virgin, O2), giving 'insert USIM' message. Can't go to the local unlocker (-closed down). I've got as far as using the Vodafone 'unlock' form, but no reply so far, perhaps not surprising given that I last used the phone with a Vodafone SIM in June 2012, and have long since transferred my original number. However, I haven't got a lot of choice in terms of getting a free unlock but to go to the original service provider. Has anybody else seen this, especially given the time gap involved ?

[Tommy]

Hello @robgoch does the device accept and work with a Vodafone SIM card?

You say you get the error message; "Insert USIM".

This is indicative of a fault with the device being unable to read a SIM card anymore and would also explain why you are now getting this message instead of being asked to enter an unlock code (NUC).

[BandOfBrothers]

Hello @robgoch

A phone that's been Unlocked to All Networks by the code supplied supplied originally by the Network won't re lock out even if Factory Reset.

Or did you have the phone unlocked originally by your now closed down "local unlocker" ? Which could be the issue as they typically force unlock phones which can present issues down the line. 

May i ask......

Have all the other Networks Sim Cards your using been activated ?

Do the other Network Sim Cards work in other phones Ok ?

Does a Vodafone Sim Card work Ok in the phone ? 

If the Vodafone Sim Card does work ok then the option could be to use a Payg Vodafone SIM card in the phone for a period of 30 days making calls, texts and using data etc and then request it's unlock via the online unlocking form using the new Payg details. 

[hrym]

I suspect tommy may be right.   The easy way to check that is to try a Vodafone SIM.   If you don't know anyone who has one, drop into a Vodafone shop and ask them to try one of theirs.  If the SIM reader is faulty (it's worth trying a clean of the contacts - just rub with a soft dry cloth), the phone will need to be repaired.   I'm not sure if the warranty will apply if there's been an unofficial unlock.