PROEL HP-X series, Service Manual

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11.2 Malfunction Analysis on SMPS:
Sequence
No.
Circuit Function Failure
1
Line
Filter/Soft ‐ start/
Rectification
‐ The AC fuse of the rear panel is burnt when connected the
electricity ‐ check the RT1 device and line filter device to see if there is
short circuit.
‐ There is smoke but it can still work while output power, check
whether the thermistor/ NPTR1 was burnt caused by the relay didn’t
pull ‐ in;
‐ Connect the jumper of 110V and ACI port, the double voltage
rectifier will let the circuit work in 110V and 120V status;
2
LLC Resonant
Converter
‐ 85°C thermal switch is often closed result to the start ‐ up
unavailable;
‐ While start ‐ up the equipment, high ‐ current will results to the burnt
out of the primary DC/DC/300V fuse;
‐ Switching transistor is not working, check the driving transformer
T2, a loop is formed by the primary current go through the
transformer T1A, resonant inductor L4 and resonant capacitor C106;
3
Fan Speed
Control Circuit
‐ Fans do not work.
‐ Fast rotating.
‐ It is easily to go into over ‐ heat protection if the fans don’t speed up
after the module temperature increasing.
4 Rectifier Output
‐ Power protection caused by the damage of high ‐ speed diodes D49,
D50, D51, D52, D67, D68, D73, D74, E4, E5, E7, E8, C6, C7, C8, C9, or
any of rectifier filter device.
‐ Power amplifier start ‐ up protection.
‐ Output distortion and power protection caused by no ± 15V output;
‐ All the indicators on the panel do not shined because no +24V
output (start ‐ up unavailable).
Repairing Guide:
1) When repairing the power board, please cut the DC/300V fuse, series connect a 100W—200W
lamp to start the machine, preventing the damage of related device when repairing.
2) When the SMPS can not be started, repeats the protection and restart, please disconnect +VCC,
‐ VCC then try to start, if it is normal, it means short ‐ circuit in amplified part, check the amplified
circuit, otherwise it is the failure of SMPS;
3) Power supply protection means ‐ all the indicators on the front panel lit and then immediately
black out;