PROEL HPX2800 - Page 9

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resultstoblockingandhigh‐current.
3
On/Off
Anti‐shock
Circuit
‐ The amplifier can not start andthereisshocksound whenshutdown:
mainly check the device of this circuit, see whether the detached
photocouplerOP1/817,Q37,Q38isdamagedornot;
4
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.
5
Rectifier
OutputCircuit
‐ Powersupplyprotectionhappenedwhileswitchon.
‐ Poweramplifierprotectionhappenedwhileswitchon.
‐ Seriousdistortionofsound.
‐ No±15Vvoltage.
‐ No +24 V output, results to all the indicator led on the panel do not
shine(start‐upunavailable)
RepairingGuide:
1)WhenrepairingtheSMPSboard,pleasecuttheDC/300Vfuse,seriesconnectone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 amplifier
circuit,otherwiseitisthefailureofSMPS.
3)Powersupplyprotectionmeans‐alltheindicatorlightsonthepanellitandthenimmediatelyblack
out.
