ELCOM Euro-50, Service Manual

Page: 35 / 82

Service manual Euro-50
Elcom s. r. o.
35
Table 4.17. Procedure for removing a faulty charger
ID Test Steps in the case of an unsuccessful test
1 The voltage of ACCUTMP is out of range.
Check connection to accumulator, or exchange for a functional one. (E50-
PWR.pdf, list power.SchDoc).
2 Check R10, R11, C12, L1, C11, C10, R5 and R4. Replace faulty components. (E50PWR.pdf, list power.SchDoc).
3 Faulty circuit NL1. Replace. (E50PWR.pdf, list power.SchDoc).
4.6.4. Malfunctions of the 3.3V (VDDQ) power source
Indicators: Absence of voltage in VDDQ.
Table 4.18. Procedure for removing malfunctions of the 3.3V power source.
ID Test Steps in the case of an unsuccessful test
1
Check the voltage of VBAT, or accumulator
connection. Check the connection of the motherboard and the power supply board - 9-
-pin cable.
2 Check the ON/OFF signal. Must be > 1.3V.
Check the connection of the motherboard and the resource board - 15-pin
cable. Check L8, circuits on MB.
Check circuits on the MB. (E50MB.pdf, list keyboard.schdoc) (E50MB.pdf, list
pwr.schdoc)
3
Measure whether there is a short on the MB
from VDDQ towards GND. Disconnect the power supply board from the motherboard and with an
ohmmeter measure VDDQ towards GND.
4 Check L3, C24, C25 Replace faulty parts. (E50PWR.pdf, list power.SchDoc).
5 Faulty circuit NL3. Replace. (E50PWR.pdf, list power.SchDoc).
4.6.5. Malfunctions of the 5V power source
Indicators: Absence of voltage in EXT5V.
Note
With a malfunction, if voltage EXT5V is detected outside of tolerance, the microcontroller switches off signal XEXT5VON.
Table 4.19. Procedure when removing malfunctions of the 5V power source.
ID Test Steps in the case of an unsuccessful test
1
Disconnect external equipment which is the powered by vol-
tage EXT5V.
Measure the voltage of EXT5V.
2 Check signal XEXT5VON.
Check R19, MB connection and PWR.(E50PWR.pdf, list power.
SchDoc).
Check circuits on MB. (E50MB.pdf, list pwr.schdoc)
Measure whether there is a short of EXT5V towards GND.
Disconnect the power supply board from the motherboard
and measure with an ohmmeter EXT5V towards GND inde-
pendently on both boards.
3 Check R6, R9, VT1, VD3, L2, C14, NL2. Replace faulty. (E50PWR.pdf, list power.SchDoc).
4 If EXT5V is higher than 5.5V.
Damaged VT1 transistor, or NL2 is permanently pinned for
the fault - replace it. Possibly check the resistors in dividers
R16, R17 a R18. (E50PWR.pdf, list power.SchDoc).
4.7. Other malfunctions
4.7.1. Malfunction in the circuits of the accumulator cover sensor
The cash register cannot be turned on and the problem is not in the power supply.
• Check the functioning of the switch SA1. Upon switching, the voltage must change on pin no. 4 of the connector XC5
from 0V to VDDQ.