DM300M Scales Support

How do I fix the weighing scale on the DM300M?

Note: Your machine may look slightly different to the one shown in the video, but the process is the same.

If the machine is not recognising weight, no prices are showing, preset prices are missing, or the machine displays manual weight, re-seat the scale:

1. Lift the scale from the franking machine.
2. Reseat the scale firmly, ensuring the contacts are fully seated on the machine.
3. If seated correctly, the franking machine will recognise the scale automatically.

---

How do I reset the scale to zero on the DM300M?

Note: Ensure the weighing platform is completely clear before zeroing.

1. From the Home screen, select the Weigh/Rate key.
2. Select Zero the Scale.
3. The machine returns to the Home screen.

---

How do I fix erratic scale readings on the DM300M?

1. Turn the machine off by removing the power lead.
2. Remove the scale and split it into its two parts.
3. Blow compressed air around both parts and also in the area where the scale sits on the machine.
4. Reassemble the scale parts, replace on the machine, then reconnect the power lead.

---

How do I fix the DM300M scale when it is not weighing correctly?

Step 1: Zero the scale. Remove all items from the scale, press Weigh/Rate and select Zero the Scale.

Step 2: Check the Serial Port setting.

1. Press the Options key.
2. Select Setup.
3. Press Page Down, then select Serial Port.
4. Attached Scale should display with a tick. If External Accounting is ticked instead, press the key next to 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 have an external weighing platform: ensure the platform is level by removing the top cover, locating the round spirit level and adjusting the feet until the dot sits inside the circle.

If the scale is still incorrect: remove it, unplug the power for 60 seconds, replace the scale, then restore power and test again. If the issue persists, contact Technical Support.

---

How do I use differential weighing on the DM300M?

Differential weighing lets you place all mail on the scale at once, then remove one piece at a time for franking. The machine calculates the postage for each piece automatically.

Important: Each piece must weigh at least the Differential Weigh Trip Weight that has been set. Pieces lighter than this minimum will not be recognised when removed.

1. Select your carrier, class, mail type, account and Envelope Message.
2. Press Weight/Rate.
3. Select Differential Weighing.
4. Place all mail on the scale (use a container if needed).
5. Remove one piece at a time and process it through the machine as normal.
6. Continue until you reach the last piece.
7. When you remove the last piece or container, the machine asks whether to print postage — select Yes or No.
8. You can add more items to continue, or select Exit Diff. Weighing to finish.

---

DM300M Scales – Frequently Asked Questions