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Troubleshooting Tips and Part # Information

Doboy B-500M Medical Band Sealer

Following are recommended tips for troubleshooting SIG Doboy B-500M and Bosch Doboy B-500M Validatable Medical Sealer problems.  You will also find a list of part numbers and descriptions for commonly used parts.

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Preventative Maintenance & Proper Use Tips*

Area of Machine

Advice / Technique

Oil Discovered in Motor

(Applies primarily to B-500M Horizontal - Style C & Style D machinery)

There is an oil seal between the motor and the gearbox.  While seals and journals are of high quality, the seal has a finite life.

Motors positioned with the gearbox above the motor (Style C&D Sealers) will eventually see some leakage of gearbox lubricant back into the motor as the seal wears out.  To prevent this occurrence, even in the long term, the gearboxes may be filled with grease rather than the standard gear lube when they are to be positioned vertically, gearbox above motor.  The grease is too heavy to migrate around a worn seal or journal.

Operator Interface Panel Indicates






Someone has inadvertently pressed the STAT key or the program has been lost.

Insure that air pressure is attached to the machine and heat settings are correct and in-range then press the MSG button.  If this does not restore the screen to show normal operating details, the program may have been lost.

You can also check the I/O LEDs on the PLC itself.  You should see some LEDs lit on the output side of the PLC.  If not, the program is very likely lost or corrupt.

Program loss is common if the machine has been in storage and not under power for one year or more.

Contact us to schedule service to get a new copy of the program loaded on your PLC.

"E-7" error code displayed on Temperature Controller

(Applies to B-500M)

Thermocouple wires are loose or broken.

Check thermocouple wires at temperature controller.  Make sure connections are tight.  If they are and "E-7" error still appears, detach wires from temperature controller and check for continuity across thermocouple wires.

Solution: If no continuity, replace thermocouple (i.e. Heater Harness Assembly)

Speed Varies Significantly at Same Speed Setting

(Applies to B-500M)

Possible causes include worn motor brushes, failing DC Speed Controller, motor nearing end of life, loose timing pulley or proximity sensor.

Check to make sure the timing pulley is secured to its shaft and that proximity sensor is sensing each tooth on the pulley as it rotates.  Check motor brushes and replace if worn.  With a multi-meter, measure DC voltage output from the DC Motor Controller - At a single speed setting, the voltage output should be constant (+/- approx. 2-3 volts is typical and OK).  Voltage output which varies more than 2-3 VDC suggests impending failure of the DC Motor Speed Control Board.

Solution: Replace worn or failing components.

General Machine Set-up:

(Applies to Doboy B-500M)

We will gladly try to talk you through proper set-up of your machine - Call us!

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* Machine troubleshooting & repairs should only be attempted by a qualified mechanic or electrician.  Power should always be disconnected prior to troubleshooting.

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Please see your factory instruction manual for additional troubleshooting tips.
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Common Replacement & Wear Parts (available at

Parts for Doboy B-500M Series Machines
Part # Description
281876 Sealing Band - Teflon-coated (two per machine)
452221 Heating Element w/ Thermocouple (B-500M)
372192 Trimmer Blade - for powered rotary trimmer models
266206 DC Motor Speed Control Board (one [1] for Sealer & one [1] for Conveyor)
476480 Brush for DC Drive Motor (Motor uses two [2] of these)
383363 Gearmotor - Standard Speed Range (Machine Style A & D)
441404 Gearmotor - Standard Speed Range (Machine Style B & C)
441534 Gearmotor - 1000 IPM Speed Range (Machine Style A & D)
441540 Gearmotor - 1000 IPM Speed Range (Machine Style B & C)
215085 Watlube Heat Release - provides a barrier to oxidation of heater elements
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