Cash Register Inexplicably Reports An Overheated Printer Head; Keyboard Malfunctions; Malfunctions In Communications; Malfunctions Of Rs232 Communications - ELCOM Euro-50 Service Manual

Service manual

4.3.6. Cash register inexplicably reports an overheated printer head

Proceed according to point 3 in the table in the subsection on Light Printing.
Table 4.10. Procedure if buttons or groups of buttons do not respond to being pressed
ID Test
1 Check the silicone keyboard, carbon switches
Check the carbon pads for buttons for damage on the bottom
1
side of the motherboard
Check the course of the signals BCDCOL[2..0] (E50MB.pdf, list
2
keyboards.schdoc)
4 Replace the DD1 circuit
Check the course of signals RW[4..0] (E50MB.pdf, list keyboards.
5
schdoc)

4.5.1. Malfunctions of RS232 communications

Table 4.11. Procedure if the cash register is not communicating through the RS232 interfaces COM1, COM2
ID Test
Check the connection of MB and connector RJ45,
1
for damage to the cable bundle
2 Check passive components on the MB
Check whether there is a logic level for signal
3 RS232TON. During communication it must be
RS232TON=H.
Check whether the charge pumps for circuit UU2 is
4
functioning. ( V(C64)>3V, V(C65)<-3V ).
Insert the terminating connector COM1 into con-
5 nector COM1. Perform the test for interface RS232
COM1 (501).
Insert the terminating connector COM2 into con-
8 nector COM2. Perform the test for interface COM2
(502)

4.5.2. Malfunctions of USB communications

Table 4.12. Procedure if the cash register cannot communicate via a USB
ID Test
Check the connection of DPS E50 PWR and the motherboard
1
and for damage to the cable bundle (15-pin)
2 Check passive components on DPS E50 PWR and DPS E50 MB
Connect the USB interface of the cash register to the USB in-
3
terface on the PC and measure voltage VBUS =5V.
6 Check VZ1, find the flaw on DPS and remove it.
Elcom s. r. o.

4.4. Keyboard malfunctions

4.5. Malfunctions in communications

Steps in the case of an unsuccessful test
Replace the silicone keyboard.
Replace the motherboard.
Check the course of the signals COL[6..0] to output DD1.
(E50MB.pdf, list keyboard.schdoc)
(E50MB.pdf, list keyboards.schdoc)
Check the path of the signals from and to the microcon-
troller
Steps in the case of an unsuccessful test
Repair the cable connection or replace it if damaged.
Replace faulty part.
If levels for the signals are not correct, check the quality of the soldering
on UU2 and measure the path of signal RS232TON from the microcon-
troller to UU2.
If voltages are not in the designated range, check C63-C66. Check
whether outputs T1OUT, T2OUT of circuit UU2 are not shorted for GND or
VCC. If necessary, replace UU2. (E50MB.pdf, list rs232-usb--sd.SchDoc)
If the test is unsuccessful, replace UU2. (E50MB.pdf, list rs232-usb-sd.
SchDoc)
If the test is unsuccessful, replace UU2. (E50MB.pdf, list rs232-usb-sd.
SchDoc)
Steps in the case of an unsuccessful test
Repair cable connection or if damaged, replace it.
Replace defective part. (E50PWR.pdf, list connectors.
SchDoc) (E50MB.pdf, list rs232-usb-sd.SchDoc)
Check L10 on DPS E50 PWR (E50PWR.pdf, list connectors.
SchDoc)
Euro-50
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