Red blink

[#1]

My Sony Ericsson K550i has met a problem recently. I changed my sim card and when I went to turn my phone on, my phone began to show the red blink on top right portion. I couldn't open the phone yet. What is the actual problem on my phone and how to get rid of that?

[Dr_Chris]

If this happened only when you changed the SIM card, then try putting the old SIM card in the phone.Was this a SIM card from a different network to the old one, and is your phone network-unlocked?

[#3]

No, I inserted a sim of same provider and the network was unlocked. I took my phone to a service center. They are telling that the JDFS has been locked. Are they telling the right thing? What do you thing about it? @ Dr_Chris.

[Dr_Chris]

Do they mean by this, that the phone has become network locked?

[#5]

No, actually they don't mean that. They're telling that the JDFS of the phone has locked from phone and this accured for changing battery during low charge on battery.

[Dr_Chris]

http://www.sonyericsson.com/cws/support/mobilephones/downloads/subject/pccompanion/k550i?cc=gb&lc=en I would suggest you try a phone repair via PC companion, which requires the phone to be switched off anyway, and see if that revives your phone.Did the service centre not suggest a solution?

[#7]

No, they didn't suggest that. I myself tried using PC Companion. But that didn't give a solution. Whenever I connect my phone using a standerd and original data cable, my phone again shows the red blink. At last the service centre has given me a solution. They told that if there is no way, they will change my motherboard and attach another good motherboard from his shop, though this is not the proper solution of my phone's problem. I'll inform you when everything goes right.

[#8]

Dr_Chris, My phone is OK now after changing the mother board. But I've faced another problem. Taking to home I attemped to update my phone's firmware but on PC Companion a dialogue box is appearing and showing 'Your phone contains modified software and can't be updated'. What will I do now to roll back to original software and update with latest software/firmware?

[Dr_Chris · Accepted solution]

Then I suggest you take it back to the same service centre that changed the motherboard, unless of course you had previously reflashed the phone with a different software version from a non-SE source such as Omnius or Davinci.