I have SRX 550 D Ultra with software version L301. Since yesterday TPS and other encrypted channels are not working. I tried to turn off and then on. Screen shows upgrading and then receiver turns off and booting again. Upgrading never takes place the Receiver turns off and on without stopping.

I disconnected the disk cable for a while and connected. Then I could watch only FTA channels.

I tried to set the box to factory setting. Still the software ver is L301.

How Can I upgrade keys and TPS AU.