This appears to be a general problem with Thomson TopUp TV DTi6300 units. I contacted them and received the attached response. Sadly it did NOT repair mine but may work for someone.
"Dear Sir/Madam,
Thank you for contacting Top Up TV.
Please note that we are currently aware of an issue affecting some Thomson DTi6300 boxes.
If your DTR will not come out of standby and is not responding to your remote control, please try the following procedures.
Step 1: Power cycle
First of all, remove the power to the box and wait 20 seconds before restoring power.
Wait while the box tries to restart and allow 2 -3 minutes for this to complete.
Try this at least twice.
If it doesn't go to the solid green light then proceed to the next step.
Step 2: Front Panel Reset
Note: This procedure will unfortunately cause you to lose all of the recordings that you have stored on the box. You will need to be able access the back of the DTR and the front panel buttons:
1. Remove power to the unit by removing the power cable from the back of the DTR.
2. Wait 20 seconds and restore the power cable while holding in the standby/power on button on the front panel of the DTR.
3. Release the standby button immediately you see a light 'blip' on the DTR front display and then immediately press the following front panel arrow buttons in sequence Up>Down>Left>Right
4.The DTR will now show the Orange LED with the Green LED flashing until the format has been completed in about 60 seconds. The DTR will return to ON automatically.
5. If requested, perform a channel scan to complete the operation.
We apologise for any inconvenience caused. Our Customer Services department can also be contacted on 08444 159 159. However, please note that we are currently experiencing high call volumes and so may not be able to answer your call as quickly as we would like.
Kind Regards,
Top Up TV"
Cooperman, May 2009