Tadiran Telecom Swift Inverter 9U Service Manual page 47

When the external unit not power on: If the internal terminal board
does not transmit 220V power, replace the main internal control panel;
if the external terminal board has 220V power, first check if (fuse,
reactor and bridge rectifier) are normal. There is still something wrong,
replace the whole set of external control unit; for the control unit
composed of several function boards, try disconnecting the
Special attention
weak-current data wires among several control boards and then power
the external unit on, if the main control panel can be powered on and
initialized successfully, then it's the module panel problems; if the
main external control panel still cannot be powered on and initialized,
replace the main external control panel.
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