DM300M Common Errors Support

The franking machine may occasionally might have contrast issues with the machines screen. If this is the case then you may be seeing a blue or blank screen, and this is a contrast issue. Fortunately it is easy to fix. Below you will be able to find out what this means and how to potentially resolve the issue.

How to fix a blank screen or a blue screen

1. Turn of your franking machine and let it power down correctly. Give the machine a few minutes to do this.

2. Turn on your franking machine and let it power up correctly. Give the machine a few minutes to do this.

You will now still see a blank screen and you will be fixing this issue ‘blind’.

3. Press the Options button.

4. Press the bottom button on the left hand side of the screen. You will see three buttons, click the bottom button.

4a. IF your screen is blue, press the second button down on the left hand side of the screen (- button). Press this several times.

4b. IF your screen is blank, press the first button down on the left hand side of the screen (+ button). Press this several times.

This should fix any contrast issues you are experiencing. If not, please contact Mailcoms.


My franking machine changes the date at 5pm.


Royal Mail requirements.


The date on your franking machine changes to the next day at 5pm every evening in order to meet Royal Mail requirements. You can still post your mail as usual. The exact date and time is included within the 2D bar code on the frank.


Some Royal Mail services are not showing on my franking machine.


Certain Royal Mail services do not appear on your franking machine for certain locations


Royal Mail does not offer all of its services to all countries. For example, while International standard is available to a wide range of countries, International tracked / tracked and signed is only available to countries where the delivering part offers these services.


Your franking machine keyboard sticks or does not respond.


The keyboard can become faulty due to normal wear and tear.


1. Remove the power lead so that the screen goes blank.

2. Buttons that are not stuck down make a gentle click when pressing. If any key seems to be stuck under the plastic cover of the franking machine, use the blunt end of a pen to gently push the key affected down slightly and see if you can centralise it back to its original position. You may need to test all the keyboard keys if it is not obvious which key is stuck.

3. Replace the power lead.

4. Test the keyboard by pressing any of the keys when the franking machine returns to the home screen.


The franking machine screen displays the “Manufacturing Mode” message.


This issue is caused by a software fault.


Restart your franking machine to resolve this issue:

1. Turn the franking machine off.

2. Wait 30 seconds.

3. Turn the franking machine back on and wait for it to initialise.


Mail Exceeds Weight Limit or Capacity is displayed on your franking machine screen.


This error displays because the item being weighed is too heavy for the class selected.


Refer to the Royal Mail rates guide to ensure that the item is within the guidelines set by Royal Mail.


The mail piece is not being weighed correctly by the scale.


The scale is not weighing correctly.


First zero the scale:

1. Remove any items from the scale.

2. Press the “Weigh/Rate” key.

3. Select “Zero the Scale”.

Then follow the below steps to ensure the “Attached Scale” option is selected on the franking meter:

1. Press the “Options” key.

2. Select “Setup”.

3. Press “Page Down” then select “Serial Port”.

4. “Attached Scale” should be visible on the display with a “tick” beside it. If “External Accounting” is ticked, this is likely the root cause of the issue – press the key to the left of “Attached Scale” to select this option.

5. The franking machine will return to the Home screen.

6. Remove the power lead from the rear of the machine, wait 60 seconds, then power the meter back up.

7. Test by weighing an item of known weight:
a £1 coin weighs 9g
a €1 coin weighs 8g

8. If the above is weighing correctly the issue is now resolved.

If you are using an external weighing platform (scale) please follow the steps below:

1. If you have an external weighing platform that sits beside the franking machine, make sure the platform is level.

2. Take the top cover off the weighing platform.

3. Locate the round glass level.

4. The dot should be located inside of the black circle. If the dot is not inside the black circle adjust the feet on the weighing platform until the dot rests inside of the circle.

If the scale is still not weighing correctly:

1. Remove the scale from the top of the franking machine, or if you have an external weighing platform unplug the cable from the back of the franking machine.

2. Unplug the power cord, wait 60 seconds.

3. While waiting, replace the scale on the top of the franking machine, or plug the external weighing platform back into the franking machine.

4. Plug the power cord back in, ensuring that it is plugged directly into a wall outlet.

Test the scale by weighing an item of known weight. If the issue is still not resolved, please contact customer support.


The display screen is blank or black.


The franking machine is in sleep mode, is not receiving power, or the contrast is too low.


Check the power LED light:

1. If the LED is amber, the franking machine is in sleep mode:
– Press any button to wake the franking machine.

2. If the LED is off, the franking machine is either turned off or does not have power:
– If there is a power switch on the back of the machine, check that it is set to the ON position ( | ).
– Check that the power cable is plugged into the back of the franking machine and into a functioning electrical outlet.

3. If the LED is green, and/or the machine makes noises like it is booting up when first plugged in, it may be a display issue where the contrast needs altering.
a. Unplug the franking machine for 10 seconds.
b. Hold down the number 4 button while plugging the franking machine back in. This will reset the contrast to the default setting.


Envelopes are not sealing or only partially sealing.


The system may be low on sealing solution, or there may be an issue with the moistener brush.


Follow these steps to resolve these possible sealing issues:

Low Sealant

1. Make sure that the sealer bottle has fluid.

2. Make sure that the sealer bottle is seated properly in the holder. It should make a ‘glug’ sound when it is seated properly.

Dry Moistener Brush

1. Make sure that the sealer bottle/moistener has fluid.

2. Make sure that the sealer bottle is installed correctly.

3. Make sure that the grate is installed correctly. An incorrect installation can keep the brush from contacting the wick properly.

4. Wet the moistener brush with EZ Seal.

5. If the brush dries out quickly, replace the moistener wick.

Dirty Moistener Brush

1. Remove the moistener brush.

2. Clean the moistener brush with plain water and rinse it thoroughly.

Worn Moistener Brush

1. Replace the moistener brush.

Glue is slow-acting

1. Remove mail from the drop stacker.

2. Examine the mail pieces and ensure that each envelope flap is seated flat against the body of the envelope.

3. If necessary, tap the mail on the table to ensure all the mail pieces are even with each other.

4. With the mail facing you, run your hand across the top of the stack while squeezing the stack together. Repeat this process as needed.

5. Allow the envelopes to dry undisturbed.

Follow these steps to clear a paper jam:

1. Turn the transport release lever clockwise to the released position.

2. Carefully pull envelope out toward the right.

3. Using a can of non-flammable canned air, and working from the left side of the machine to the exit, blow onto the feed deck that the envelopes/tape sheets travel on.
Important: Make sure to spend enough time in this step to ensure that dust and debris are removed. Clean the paper path with a soft dry cloth where possible. If sensor holes become blocked with paper dust, air dusters cannot clear the blockage.

4. Turn the transport release lever counter clockwise to the home position.