Hi, when I hold the 'on' button the light turns red, but after about a second it turns off - express is not working. I unscrewed the base - everything seems to be fine there, no burnings or whatever. Any advice what could it be?

You probably just need to Pair the handset with the base again.
So, you have to set the phone in the main base, not just a charging base.

Some of the AT&T phones need you to disconnect the battery for about a minute to reset (this will not lose you stored numbers). Then pair the phone and base again.

Some models have a PAIR button on the bottom of the base.
Press and hold the PAIR button until the MUTE light on the headset base turns on (about four seconds) and release the button.

Return the headset to the headset base for registration.

Registration may take about 30 seconds to complete. The MUTE light on the headset base turns off. The headset ON/OFF light turns blue
on the first headset registered. The headset ON/OFF light turns orange on the second headset registered.

You should be good to go!
All the best to you,
Kerry Hostetter

Unplug the AirPort Express from the power outlet and press and hold the reset button. While still holding down the reset button, plug the device into a power outlet. Hold down the reset button until you see the light flash green four times. Let go of the button and the device will reset itself. Wait the requisite 45 seconds and configure it with the AirPort Express Assistant or AirPort Admin Utility.
This performs a factory reset.

Welcome to Fixya

Try the troubleshooting procedure below:

Step 1 - Turn off the playstation 3 by holding the power button on the front of the unit till the power light is red.

Step 2 - Touch and hold the power button, you will hear the first beep, meaning the playstation 3 is powering on. Continue to hold the power button and after about 5 seconds, you will hear a second beep, indicating the video reset. Continue to hold the power button and after about 5 seconds, you will hear a third beep and the system will power off (power light is red).

Step 3 - Touch and hold the power button, you will hear the first beep, again for the playstation 3 to power on. Continue to hold the power button and after about 5 seconds, you will hear a second beep for video reset. Continue to hold the power button and after about another 5 seconds you will hear a quick double beep. At this point release the power button. if you succeeded in activating the safe mode, you will see a message on the screen saying 'connect the controller using a USB cable and then press the PS button.

Step 4 - Perform the safe mode options in the following order until one of the options works for you. If one option works, do not continue onto the other options.

Restore Default Settings
Restore File System
Rebuild Data Base
Restore PS3 System etc...

Cheers!

If you need further help, reach me via phone at https://www.6ya.com/expert/elixirjose_00375ea24bd8141b

Welcome to Fixya

Try the troubleshooting procedure below:

Step 1 - Turn off the playstation 3 by holding the power button on the front of the unit till the power light is red.

Step 2 - Touch and hold the power button, you will hear the first beep, meaning the playstation 3 is powering on. Continue to hold the power button and after about 5 seconds, you will hear a second beep, indicating the video reset. Continue to hold the power button and after about 5 seconds, you will hear a third beep and the system will power off (power light is red).

Step 3 - Touch and hold the power button, you will hear the first beep, again for the playstation 3 to power on. Continue to hold the power button and after about 5 seconds, you will hear a second beep for video reset. Continue to hold the power button and after about another 5 seconds you will hear a quick double beep. At this point release the power button. if you succeeded in activating the safe mode, you will see a message on the screen saying 'connect the controller using a USB cable and then press the PS button.

Step 4 - Perform the safe mode options in the following order until one of the options works for you. If one option works, do not continue onto the other options.

Restore Default Settings
Restore File System
Rebuild Data Base
Restore PS3 System etc...

Thank you!

If you need further help, reach me via phone at https://www.6ya.com/expert/elixirjose_00375ea24bd8141b

Welcome to Fixya

Try the troubleshooting procedure below:

Step 1 - Turn off the playstation 3 by holding the power button on the front of the unit till the power light is red.

Step 2 - Touch and hold the power button, you will hear the first beep, meaning the playstation 3 is powering on. Continue to hold the power button and after about 5 seconds, you will hear a second beep, indicating the video reset. Continue to hold the power button and after about 5 seconds, you will hear a third beep and the system will power off (power light is red).

Step 3 - Touch and hold the power button, you will hear the first beep, again for the playstation 3 to power on. Continue to hold the power button and after about 5 seconds, you will hear a second beep for video reset. Continue to hold the power button and after about another 5 seconds you will hear a quick double beep. At this point release the power button. if you succeeded in activating the safe mode, you will see a message on the screen saying 'connect the controller using a USB cable and then press the PS button.

Step 4 - Perform the safe mode options in the following order until one of the options works for you. If one option works, do not continue onto the other options.

Restore Default Settings
Restore File System
Rebuild Data Base
Restore PS3 System etc...

All the best

If you need further help, reach me via phone at https://www.6ya.com/expert/elixirjose_00375ea24bd8141b

Welcome to Fixya

Try the troubleshooting procedure below:

Step 1 - Turn off the playstation 3 by holding the power button on the front of the unit till the power light is red.

Step 2 - Touch and hold the power button, you will hear the first beep, meaning the playstation 3 is powering on. Continue to hold the power button and after about 5 seconds, you will hear a second beep, indicating the video reset. Continue to hold the power button and after about 5 seconds, you will hear a third beep and the system will power off (power light is red).

Step 3 - Touch and hold the power button, you will hear the first beep, again for the playstation 3 to power on. Continue to hold the power button and after about 5 seconds, you will hear a second beep for video reset. Continue to hold the power button and after about another 5 seconds you will hear a quick double beep. At this point release the power button. if you succeeded in activating the safe mode, you will see a message on the screen saying 'connect the controller using a USB cable and then press the PS button.

Step 4 - Perform the safe mode options in the following order until one of the options works for you. If one option works, do not continue onto the other options.

Restore Default Settings
Restore File System
Rebuild Data Base
Restore PS3 System etc...

Cheers

If you need further help, reach me via phone at https://www.6ya.com/expert/elixirjose_00375ea24bd8141b

The compatibility setting, in almost 100% of the cases, should be set to "1".  You can find it on the side of the base, it's a little turn wheel that will turn if you stick your thumbnail in it and twist.  I have seen one instance on the Cisco IP phones that requires the compatibility setting to be on 5, so try that as well.
If you have a lifter installed, make sure that the short telephone cable that comes out of the back of the headset's base unit is plugged into the handset port of the telephone (where the handset coily cord is normally plugged into).  You would then plug the handset coily cord into the front of the headset base unit.  Make sure you have that configuration, and try again.
Finally you can try a re-set.  To do this you should lift the headset off of the charging base, make sure the green light on the top of the base is off (the headset is off), and then do the following: 1. Hold down the mute button and the call answer button at the same time. (The mute button is the black little wheel on the top of the headset itself.  If you use the tip of your finger to push that straight in, it will mute the headset) 2.  Keep holding both buttons down until the green light below your thumb on the headset flashes for 2 consecutive series. 3.  Let go.  Wait about 20 seconds then try answering.
If this doesn't work, try a re-subscription: 1. Place the headset back on the charging base. 2. The two microphone volume adjust buttons on the back of the BASE unit should be pressed together.  This will start the red light and the yellow light blinking on the front of the base unit. 3. Hold the mute button down while the headset is still on the charging base.  Hold it down until the red light stops blinking. 4. Disconnect the power to the base so that the red light and yellow light turns off. 5. Plug the power back in after about 5 seconds of it being disconnected and make sure the red light on the front of the charging base is now solid and the yellow light is flashing. 6.  Pick up the headset and try again.

Try a system reset:
1. Lift the headset off of the charging cradle (the base).  Make sure the headset is turned off.  The green light on the base won't be on if the headset is turned off. 2. Hold down the call answer button on the headset at the same time as mute button.  The mute button is found on the little black wheel on the top of the headset.  Use the tip of your finger to push it straight in. 3. Hold both buttons until you see a green light on the headset flash.  It will be right below your thumb.  Hold both buttons until the green light flashes for a series of 2 flashes.  Then let go of both buttons. 4. Put the headset back on the charging cradle and wait 30 seconds.  Lift it back off and try again. 5. If this doesn't work repeat the process once more or try a resubscription.
Resubscription procedure:
1. Put the headset back onto the charging cradle.  Make sure the red light on the base is on and the yellow light is flashing. 2. On the back of the base there are two buttons for the microphone adjustment that can be pressed down.  Press both of those down until the red light and yellow light on the front of the base start flashing. 3. While the headset is still on the charging cradle press and hold the mute button until the red light on the base goes solid, and the yellow light stays flashing. 4. Unplug the power to the base and then plug it back in. 5. Wait 20 seconds and try.

Make sure the headpiece is charged. Turn the headpiece off by pressing the little black button on top of the earpiece and holding for about 5 seconds. Turn the earpiece back on again the same way. You should have a slow flashing blue light on the mic boom. The base station will now try to find the earpiece and within about 20 seconds the red light on the base should be steady and blue light on top should be on.
If this doesn't work you may need to manually pair the earpiece to the base by pressing and holding the Listen Volume Adjust + Button and headset Call Control Button on the earpiece until the light on the mic boom flashes red and blue repeatedly. As above, the base station will now try to find the earpiece and within about 20 seconds the red light on the base should be steady and blue light on top should be on.

Begin with the headset turned off. Press and hold down the silver call control button in for 6-10 seconds. The light will flash blue first. Continue to hold the button down then release the button when the indicator light starts flashing red then blue.