Product

• Trendsetter 400
• Trendsetter 800
• Trendsetter News
• Trendsetter VLF Autoloader
• Lotem 400 Quantum
• Lotem 800 Quantum
• Lotem 800 Type II

Machines affected

• Trendsetter 800 -- serial numbers TE 235, 236, 238 and higher, PX072 and higher
• Trendsetter VLF AL -- all machines
• Trendsetter News -- all machines
• Lotem 400 Quantum -- all machines
• Lotem 800 Quantum -- all machines
• Lotem 800 Type II -- all machines

Component

Carriage drive board (48V DC)
Part#'s 10-3761, 10-4935, 503C01525, and 10-4975.

Note:  On Trendsetter 800, does not apply to older style carriage drive board 10-1418C. On Trendsetter VLF AL, only applies to picker and L-conveyor carriages. Does not apply to carriage drive board 10-1312C used on the Trendsetter VLF base machine.

Symptoms

This problem can manifest itself in many ways, including (but not limited to):

• Subscan/slowscan vibration image artifacts (Trendsetter 400/800/NEWS and Lotem models only)
• Abnormal carriage/picker sounds
• Stalling or erratic/unexpected movement of carriage/picker
• "OC" LED light lit on the carriage drive board
• Severe burning or meltdown of connector CM-DRIVE, caused by short on pins A+ and A-
• High motor operating temperature

Cause

The main cause of this problem seems to be an excessive DC offset on the drive board due to the brand of capacitor used.

Solution

If you see any of the symptoms listed above, or you observe other strange carriage-related behaviour, please follow these steps before replacing the drive board or motor:

1. Set the carriage/picker in motion. Only a very slow speed is needed for these tests.
   • For MPE based Trendsetters, type carriage move 50
   • For Lotem devices and MCE based Trendsetters, type carriage move 3
   • For Trendsetter VLF AL, type picker move 3000 10
2. Set a voltmeter to measure DC Voltage.
3. For 10-3761, 10-4935, and 10-4975:
   Using the voltmeter, measure the DC voltage between ground and board test points TP5, TP9, TP15 and TP17.
   
   Ideally, these should all measure 0V to ground, which would indicate zero DC offset. Any reading greater than 150mV for any of the test points is excessive and the board should be replaced. Service stock has been reworked, so the replacement board should not have the faulty capacitors.
   
   It is very important that the carriage is in motion during this test. If the motor is not spinning, then any of the testpoints could have valid signals up to 5V.
4. For 503C01525:
   Using the voltmeter, measure the DC voltage between ground and board header pins J4-1, J4-2, J4-6 and J4-7.
   
   Ideally, these should all measure 0V to ground, which would indicate zero DC offset. Any reading greater than 150mV for any of the test points is excessive and the board should be replaced. Service stock has been reworked, so the replacement board should not have the faulty capacitors.
   
   It is very important that the carriage is in motion during this test. If the motor is not spinning, then any of the testpoints could have valid signals up to 5V.
5. Idle the carriage or return the picker.
   • For Trendsetter 800, type carriage idle
   • For Lotem devices and MCE based Trendsetters, type carriage idle
   • For Trendsetter VLF AL, type picker init

Note about Trendsetter NEWS: There have also been carriage problems with Trendsetter NEWS machines, exhibiting similar symptoms. The cause can be different, however.
Some newspaper devices that use a Thermal II head have too few head flex track links. The head will stall due to the flex track not having enough travel at one end of the carriage. All Trendsetter NEWS and Trendsetter 800 machines using the Thermal II head must have 19 links in the head flex track (18-3345), not including the mounting links at each end.

See also

• Carriage driver board 503C01525B power supply feeds noise into MCE board, output device spontaneously resets

Technical contact(s)

• Steve Froese (Trendsetter 800)
• Angus Gillon (VLF)
• Iris Mordan (Lotem)

Submitted by

Bill Dall

Date submitted

25 Oct 2002