Check the toner container lights on

Error code C0630 on an Olivetti D-Copia 2500 multifunction printer typically indicates a problem with the toner cartridge or the waste toner container. This error can be caused by a number of different issues, including a low toner level, a problem with the toner cartridge or waste toner container, or a problem with the printer's sensor or control board.
Here are a few steps you can take to try and resolve the issue:

• Check the toner level in the cartridge and replace the cartridge if it is low.
• Make sure that the toner cartridge is properly installed and that all of the connections are secure. If the error persists after replacing the cartridge, the new one might be faulty.
• Check the waste toner container, if your printer has one, and make sure it is properly installed and not full.
• Clean the toner sensor if there is one and check for any debris or foreign objects that may be causing the error.
• If the problem persists, it's possible that there is a malfunction in other parts of the machine such as the control board.

It's recommended that you check the printer manual or contact Olivetti Support for more specific instructions or troubleshooting steps that can help identify the cause of the issue. They can also assist you in determining if it would be better to repair or replace the machine.

Possible fix, and free service manual online, but unsure if that is the same error message:
https://printcopy.info/index.php?mod=erc&brand=Canon&model=iR+Advance+C5240i&page=12

Quoting from link above:

• Code: E020-0491
• Description:Error in Bk Developing Assembly
  Error in signal upper limit with ATR sampling detected value
• Remedy:1. Check toner leak from the Toner Buffer Unit. 2. Check toner level in the Toner Container. 3. Replace the Developing Assembly. 4. Check short-circuit of the harness with the Toner Buffer Supply Sensor (PS4)

the top of the waste toner container must be cleaned 100% from the toner because it should be a light sensor that has to pass through it , if its spoiled with toner the light cannot pass through it ,so i recommend you to empty the waste toner container first and wash it with water and drying it well before using it again.

Error in Cover Sensor (PS14) in M Toner Container

Description Unable to detect opening of the Toner Container Inner
Cover when removing the Toner Container.
Remedy Identify the cause of the error whether it is due to link
mechanism to open the Toner Container Inner Cover or
problem at the Toner Container Inner Cover Sensor side. ?
1. Perform the user mode (Adjustment/Maintenance>
Replace Specified Toner) to check if the Toner Container
Inner Cover opens normally (damage, slide of shaft area,
etc.). ?
2. Check if the Toner Container Inner Cover Sensor is
soiled and the installation of the sensor. ?
3. Check the service mode (COPIER> I/O> DCON> P024
bit9) to see that the output value of the Toner Container
Inner Cover Sensor is changed normally when opening/
closing the Toner Container Inner Cover. ?
If it is normal, the value becomes 0 by rotating the Set-on
Drive Shaft with the attached tool and opening the Toner
Container Inner Cover. When closing the Toner Container
Inner Cover by hand, it becomes 1. ?
3-1. When the Toner Container Inner Cover is not opened
although the Set-on Drive Shaft rotates, check the drive
system from upstream (Set-on Drive Unit -> Hopper Unit
-> Bottle Base Unit -> Toner Container Inner Cover Unit). ?
If it is damaged, replace the damaged part and then
perform step 5 and later steps. ?
3-2. When the output value is not changed normally
although the Toner Container Inner Cover can be opened/
closed, check the Sensor Harness (to see if the harness
is caught, disconnected or physically removed, *including
the Relay Connector). ?
If there is no problem, replace the sensor. After checking
the output value in step 3, perform step 5 and later steps. ?
4. If the problem is not solved by replacing the foregoing
parts, replace the Drum Driver PCB (UN4) and then
perform step 5 and later steps. ?
5. Clear the error in service mode (COPIER>
FUNCTION> CLEAR> ERR), and then turn OFF and then
ON the main power. ?
6. Replace the toner (reinstall the removed Toner
Container) at least once in user mode (Adjustment/
Maintenance> Replace Specified Toner), and check that
toner replacement can be performed normally.

Toner container problem
Toner level is not detected when toner
empty is detected.

Check the connection of connector YC5 on
the engine PWB and the continuity across
the connector terminals. Repair or replace if
necessary.
Defective toner
container sensor.
Replace the toner container sensor.

The C25 stores toner in a waste toner container. On the front of that container there is rectangular clear window that fits into a sensor when installed into machine. The sensor passes a beam of light through that window. When the bottle is full there is toner inside that clear plastic window which stops the light from making it through the window and the machine will tell you the waste toner is full. Just dumping the container out will not clear that window and by putting it back in the machine you will get the same toner full message. If you are going to try to reuse that container you will have remove the black plastic cover that is glued to the container above the clear plastic. Then use something like a Qtip to clean all the toner off of that clear window(much easier and faster to just replace in with a new container). if you still get the waste toner full message after you install it then remove it and wipe off the sensor that the clear window sits in. This will clear the message and you can continue your copy job.

The Canon Laser Shot LBP2900, does not use ink(liquid), it uses a Cartridge called "Toner" which contain "black powder" form in the cartridge capsule.

If you wish to check the Toner Level, refer to this guide @ http://support-in.canon-asia.com/contents/IN/EN/8100134600.html

Hope it helps.

1 Open the top cover.
2 Open the front cover.
3 Lift the process unit, together with the toner container, out of the machine and place it on a clean, level surface.
Do not stand the process unit on end and never expose the drum to normal lighting for more than five minutes.
4 Pull the lock lever towards to the UNLOCK position then pull the toner container release lever to the right.
5 Gently remove the old toner container. Put it in the supplied plastic bag and dispose of it according to local rules and regulations.
6 Shake the new toner container horizontally 5 or 6 times to distributed the toner inside.
7 Remove the orange protective seal.
8 Align the knob on the left side of the container with the groove in the process unit and insert it. Push on the PUSH HERE marks until the container clicks into place.
9 Push the lock lever back into its locked position (away from you).
Clean the charge and registration roller.
Refer to Cleaning the Charger and the Registration Roller on page 5-4.

What model MFC Brother Printer do you have? The waste toner is left over toner from each print or copy that isn't used. It collects in a different spot in each printer. Usually the waste toner container is with the regular toner cartridge. The printer is able to detect when the waste toner is full by a light sensor in or near that container. Sometimes excess toner collects on the sensor itself and causes it to think the waste toner is full when it actually isn't. Try finding the waste toner container and empty it or replace it. clean the sensor that is on or near the container. it is likely a small black plastic piece that has 2 or 3 small wires coming from it. The model of printer will help to identify where the container is.