Smart AY Tango Service Manual page 52

• Check the 24way power cable (not shown in image) from CN4 of the ATX
DC-DC to the ATXPWR connector of the internal PC. Reseat the connector at
both ends (some units will have the cable soldered at the ATX DC-DC end).
• Check the cable running from the power switch to the internal PC. This cable
should be connected to Pins 9 and 11 of the JFP connector on the PC (pin 1 is
indicated with an arrow – pins 9 and 11 are adjacent to R14 and R17). Check
this connection.
• Use a multimeter to check the main power switch and cable.
At this point you have checked all components that should affect the
motherboard sending a power on signal to the ATX DC-DC. If you still don't
have any power, proceed as follows.
• Disconnect the 2 x 4pin HDD power connectors coming out of the ATX DC-
DC.
• Remove the cable from the ATXPWR connector of the motherboard.
• The power supply is now fully disconnected from all console components.
• Using a jumper wire, momentarily connect the green wire with any black
wire in the cable harness coming from CN4 of the ATX DC-DC. This should
force the PSU to power on.
• Measure the voltages on any of the cables coming from the ATX DC-DC to
confirm that it is functioning correctly. Measure all voltages between
coloured wire shown and black (GND). Voltages should be as follows.
Orange
Red
Yellow
Blue
Purple
If the voltages are all OK then the problem is most likely with the internal PC
(not controlling the start-up) or with the power switch and wiring (checked
above). Another possibility is that one of the console components has failed and
is shorting out the PSU, stopping it from powering up. Try powering the
console on with various components disconnected such as the LCD,
Touchscreen, Hub and the control surface PCBs (HKLOW, HKPID, etc).
If any voltages are missing, the ATX DC-DC is faulty and will need replacement.
th
14 Oct 2009
+3V3
+5V
+12V
-12V
+5V (Standby)
Tango Smart Console™ Service Manual
52