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Geschreven op Wednesday, 31 July 2013 om 4:33

UPS power failure phenomenon: a mpe 1 kva UPS power supply, on-line boot after bypass normal output, press the ON key, can work by bypass into the inverter, but immediately jump bypass, and fault lights, buzzer alarm sirens, press OFF, stop buzzer alarm, bypass output to normal.
UPS power supply malfunction analysis and maintenance: according to the fault phenomenon, a preliminary thought control circuit parts work is normal, because the press ON button, after time delay 1 ~ 2 seconds will automatically jump to the inverter working status, fault appear immediately, but it can judge the fault circuit is roughly.
(1) soft start control circuit fault /
2) power amplifier circuit board output short-circuit fault;
(3) the above two parts have short circuit fault. Because the bypass output is normal, can largely be ruled out the possibility of a microcomputer, socket external devices such as short circuit. Open the chassis, found that the soft start burned sealant to deformation, cut the lead wire, soft start is measured with a multimeter one by one for each element of the piece, have burn out, change a new soft start, turn ON the juice and press ON the switch, the failure remains, prove fault still exist.
Turn off Original Acer Aspire 5534 Series Dc Power Jack Wcable1, power amplifier circuit board output part of the diode is measured with a multimeter Q13, Q14 during April 12-15, Q19, Q20 are normal, high-power MOS tube (YTFP250) Q7, Q22 Q23, also is normal, another arm of high-power MOS tube Q5, Q17, Q18, found Q17 and Q18 D resistance between the pole and S pole of 0 Ω, Q5 no abnormalities are found. Due to Q17, Q18 two power tube of D and S pole is parallel, thus Q17, Q18 welding down separate measurement, Q18, normal Q17 D and S pole is really has the breakdown to short circuit.
Because of the market difficult to buy YTFP250, check the manual that IRFP250 parameters and YTFP250 nearly the same. With a IRFP250 change after, again with multimeter measuring online resistance is equal to two arms, turned ON after the power is connected, press ON the switch, inverter can work, but the output is about 230 v, adjust the micro adjustment potentiometer VR3 output, the output is 220 v, with wax or sealant sealed VR3, connected to the load, the boot after everything is normal, troubleshooting.
DC POWER JACK ACER ASPIRE 5220 5220G CABLE 90W CJ16 fault phenomenon: a mpe 1 kva UPS power supply, on-line boot bypass working properly, press ON the switch, no response, no closed relay, inverter can't work.
UPS power supply malfunction analysis and maintenance: according to the fault phenomenon, can be roughly judge fault in panel or relay circuit. Open the housing, remove the panel, use multimeter to measuring relay, normal. Due to the press ON switch doesn't work, doubt ON switch is damaged, the multimeter red, black in switch ON both ends of the two respectively, press the switch ON, resistance to 0 Ω, prove that switch ON is good.
Connected to power supply, dc voltage with a multimeter measurement switch ON both ends of the earth respectively dc voltage, voltage at one end, and found no voltage at the other end, and no voltage side by resistance R99 and resistor connected R100, reoccupy multimeter measuring R99 respectively at both ends of voltage, the voltage at one end, and no voltage linked to ON end. Turn off the power supply, electric resistance R99 online for infinity, and R99 Ω resistance value should be 100 k, in a 100 k Ω resistance, press power ON, press the switch ON, the inverter can work, the output is 220 v ac voltage, load is connected, can work normally, troubleshooting.
SANTAK UPS power failure phenomenon: a nt $1000 va square-wave backup power supply, the mains power supply is operating inverter, the buzzer of nights, long alarm light is bright, no output.
(Acer Aspire 5920 5920g Dc Jack Cable Harness 65w) analysis and maintenance, users reflect the UPS inspection two days ago, the city DianZhuan inverter, the machine can be heard within a "shout shout" abnormal sound, and sound is very big, but there's output, after a period of time, will appear the fault phenomenon. Open the casing, in the case of no mains no-load boot, found that at the moment of opening switch, output UPS, fan also turn up (fan using UPS output voltage is 220 v). About 2 seconds later, inverter output, appear the fault phenomenon, final drive circuit is measured with a multimeter and found that Q1 to Q3 has been breakdown short circuit (Q1 to Q3 used in parallel connection).
Accordingly, DianZhuan inverter with UPS before failure occurred in the city's "shout shout" sound, is the final stage of UPS power circuit of the two arms uneven output transformer caused by the abnormal voice, ( CMOS Battery IBM ThinkPad x30 x31 x32 R50e CB08A)is the Q1 to Q3 or Q4 to Q6) damage, since there is no timely maintenance, result in Q1 to Q3 level at the end of the power circuit of the arm all damage, cause a short circuit, so that the overcurrent protection circuit action, blockade pulse output inverter work, make the inverter output. Replace Q1 to Q3, and other elements can be measured without damage, after open the power switch, UPS inverter output back to normal, troubleshooting.
SANTAK UPSDC CABLE POWER JACK TOSHIBA SATELLITE P305D-S8845 CJ20 power failure phenomenon: a nt $600 va sine wave backup power supply, the city DianZhuan inverter with output, buzzer as sirens LDE light-emitting tube light.

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