Swecoin TTP 5200, Service Manual

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December 2001 TTP 52x0 Series Kiosk Printer— Service Manual 49
5.2 Revisions
There are two revisions on a 728 board:
1. The Printed Circuit Board (PCB) revision is etched into the board.
2. The Printed Circuit Assembly (PCA) revision that is printed on the label attached to the
assembled PCB, and indicates what components are fitted.
5.2.1 PCA Revision E
REASON FOR CHANGE
In order to make the TTP5xx0 series compatible with the ISO-1284 Compatibility-mode
timing, some components on the PCB has been changed. This allows EPP or ECP mode
to be selected on the parallel port of the PC.
Some computers also had problems communicating with the printer at higher baud rates.
This has also been found to be related to component values on the PCB.
EMC testing has been performed to verify that the modifications comply with the EMC
rules.
CHANGE DESCRIPTION
The following components have been changed:
Name Old value New value
C21 1nF 470pF
C27 1nF 470pF
C41-42 1nF 470pF
C43 10nF 100pF
C47-51 10nF 100pF
BACKWARD COMPATIBILITY
The new boards are fully backward compatible.
5.2.2 PCA Revision F
Compressed text has been experienced especially at high stepper motor temperatures.
To increase the pull force of the printer stepper motor the reverse clamping voltage of the
circuitry has been increased from 24 to 36V. This also reduces heat production in the
motor. An EMI filter has been added to the printhead data output to further decrease
radiated EMI.
CHANGE DESCRIPTION
The following components have been added:
Z1, and Z2 = BZX85/C12