The manual is available at
www.oneforall.com (switch to e.g. UK site, and click on Service and Support. The instructions are on page 14 (990 command).
From the manual:
Example: To blink out your television code:
1. Press and hold down the MAGIC key (for about 3 seconds). The screen will change to the setup screen.
2. Press OTHER.
3. Press 9 9 0, the animated IR Indicator will light up twice.
4. Press and release the TV key to select the device type you like to check the code for.
5. For the first digit of your four-digit code, press 1 and count the blinks of the animated IR Indicator. If there are no blinks, the digit is “0”.
6. For the second digit, press 2 and count the animated blinks. If there are no blinks, the digit is “0”.
7. For the third digit, press 3 and count the animated blinks. If there are no blinks, the digit is “0”.
8. For the fourth digit, press 4 and count the animated blinks. If there are no blinks, the digit is “0”. Now you have found your four-digit code.
9. Press ENTER to return to the setup screen OR press a device key if you want to perform the blink out for another device.
10. Press and hold ESC (for about 3 seconds) to return to user mode.