DM300M Common Errors Support

How do I fix a blank or blue screen on the DM300M?

To fix a blank or blue screen on the DM300M, restart the machine, then adjust the contrast using the buttons on the left of the screen.

1. Turn off your franking machine and let it power down correctly. Give it a few minutes.
2. Turn the machine back on and let it power up correctly. Give it a few minutes. The screen may still appear blank, so you will adjust the contrast “blind”.
3. Press the Options button.
4. Press the bottom button on the left-hand side of the screen (there are three buttons — press the bottom one).

• If your screen is blue, press the second button down on the left (the − button) several times.
• If your screen is blank, press the first button down on the left (the + button) several times.

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Why does my DM300M change the date at 5pm?

Your DM300M changes the date to the next day at 5pm every evening to meet Royal Mail requirements. You can still post your mail as usual — the exact date and time is included within the 2D barcode on the frank.

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Why are some Royal Mail services not showing on my DM300M?

Some Royal Mail services do not appear on your DM300M because Royal Mail does not offer every service to every destination. For example, while International Standard is available to a wide range of countries, International Tracked / Tracked & Signed is only available where the delivering party offers those services.

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How do I fix sticking keys on the DM300M keyboard?

To fix sticking keys on the DM300M, power the machine down and gently re-centre any stuck key with the blunt end of a pen.

1. Remove the power lead so the screen goes blank.
2. Keys that are not stuck make a gentle click when pressed. If a key seems stuck under the plastic cover, use the blunt end of a pen to gently push it down and re-centre it. You may need to test all keys if it is not obvious which one is stuck.
3. Replace the power lead.
4. Test the keyboard by pressing keys once the machine returns to the Home screen.

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How do I clear the “Manufacturing Mode” message on the DM300M?

To clear the “Manufacturing Mode” message on the DM300M, restart the machine — this message is caused by a software fault.

1. Turn the franking machine off.
2. Wait 30 seconds.
3. Turn the machine back on and wait for it to initialise.

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How do I fix “Mail Exceeds Weight Limit or Capacity” on the DM300M?

The “Mail Exceeds Weight Limit or Capacity” message on the DM300M means the item being weighed is too heavy for the class selected. Refer to the current Royal Mail rates to ensure the item is within the guidelines for your chosen class.

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How do I fix a DM300M scale that is not weighing correctly?

To fix a DM300M scale that is not weighing correctly, first zero the scale, then make sure the Attached Scale option is selected.

Step 1 — Zero the scale

1. Remove any items from the scale.
2. Press the Weigh/Rate key.
3. Select Zero the Scale.

Step 2 — Check the Attached Scale setting

1. Press the Options key.
2. Select Setup.
3. Press Page Down, then select Serial Port.
4. Attached Scale should show with a tick. If External Accounting is ticked instead, press the key to the left of Attached Scale to select it.
5. The machine returns to the Home screen.
6. Remove the power lead, wait 60 seconds, then power the machine back up.
7. Test with a known weight: a £1 coin weighs 9g; a €1 coin weighs 8g.

If you use an external weighing platform, make sure it is level: remove the top cover, locate the round glass spirit level, and adjust the feet until the dot rests inside the circle.

If the scale is still incorrect: remove the scale (or unplug the external platform), unplug the power for 60 seconds, replace the scale, restore power and test again. If the issue persists, contact Technical Support.

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How do I fix no power or a blank display on the DM300M?

To fix no power or a blank display on the DM300M, check the power LED to identify whether the machine is asleep, has no power, or needs the contrast resetting.

1. If the LED is amber, the machine is in sleep mode — press any button to wake it.
2. If the LED is off, the machine is turned off or has no power. Check any power switch on the back is set to ON ( | ), and that the power cable is plugged into the machine and a working outlet.
3. If the LED is green (or the machine makes booting noises when first plugged in), it may be a display contrast issue. Unplug the machine for 10 seconds, then hold down the number 4 button while plugging it back in to reset the contrast to default.

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How do I fix sealing issues on the DM300M?

To fix sealing issues on the DM300M, check the sealing solution level and the condition of the moistener brush.

Low sealant

1. Make sure the sealer bottle has fluid.
2. Make sure the sealer bottle is seated properly in the holder — it makes a “glug” sound when seated correctly.

Dry moistener brush

1. Make sure the sealer bottle/moistener has fluid.
2. Make sure the sealer bottle is installed correctly.
3. Make sure the grate is installed correctly — incorrect installation stops the brush contacting the wick.
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 it with plain water and rinse thoroughly.

Worn moistener brush

1. Replace the moistener brush.

Slow-acting glue

1. Remove mail from the drop stacker.
2. Check each envelope flap is seated flat against the body of the envelope.
3. If necessary, tap the mail on the table so all pieces are even.
4. With the mail facing you, run your hand across the top of the stack while squeezing it together. Repeat as needed.
5. Allow the envelopes to dry undisturbed.

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How do I clear a paper jam on the DM300M?

To clear a paper jam on the DM300M, turn the transport release lever clockwise, remove the envelope, and clean the feed deck with canned air.

1. Turn the transport release lever clockwise to the released position.
2. Carefully pull the envelope out toward the right.
3. Using 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.
4. Turn the transport release lever anticlockwise to the home position.

Important: Spend enough time on the cleaning step to remove all dust and debris. Clean the paper path with a soft dry cloth where possible. If the sensor holes become blocked with paper dust, air dusters cannot clear the blockage.

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DM300M Common Errors – Frequently Asked Questions