BU-120/HTS-20
SAFETY INFORMATION
WarningLeakage/ResistanceCheck
Any person performing service of this unit will be exposed toBefore returning the unit to the customer, perform a leakage
hazardous voltages and the risk of electric shock. It isor resistance test as follows:
assumed that any person who removes the amplifier from this
cabinet has been properly trained in protecting againstLeakage Current. Note there is no power switch on this unit.
avoidable injury and shock. Therefore, any serviceWhen the power plug is plugged in, the unit is live. Connect
procedures are to be performed by qualified service personalthe unit to its rated power source. Using an ammeter,
ONLY!measure the current between the neutral side of the AC
supply and chassis ground of the unit under test. if leakage
Cautioncurrent exceeds 0.5mA, the unit is defective. Reverse the
polarity of the AC supply and repeat.
This unit does not have a power switch. Hazardous voltagesResistance. Measure the resistance from either side of the
are present within the unit whenever it is plugged in.
line cord to chassis ground. If it is less than 500k ohms, the
Before the amplifier is plugged in, be sure its rated voltageunit is defective.
corresponds to the voltage of the AC power source to be
used. Incorrect voltage could cause damage to the amplifierWARNING! DO NOT return the unit to the customer if it fails
when the AC power cord is plugged in. Do not exceed ratedone of these tests until the problem is located and corrected.
voltage by more than 10%: operation below 90% of rated
voltage will cause poor performance or may shut the unit off.
ListofSafetyComponentsRequiring
ExactReplacements
F1Fuse SLO BLO 1.0A 250V 20mm.
UL approved
PWRCORDSPT-2 or better with polarized plug, UL
approved wired with the hot side to fused side.
Use with factory replacement panel strain relief
only.
T1Transformer. Use only factory replacement.
DBR or D1Bridge diode. Use only factory replacement.
C1, 24700uF, 50V electrolytic filter caps. Be sure
replacement part is at least the same working
voltage and capacitance rating. Also the lead
spacing is important. Incorrect spacing may
cause premature failure due to internal cabinet
pressure and vibration.
C610uF 50V electrolytic radial* BU120 and HTS-20 rev. A only.
S53AMI or CN1Power output module. Use only factory
replacement
FaceplateFaceplate. Use only factory replacement
Air leak coverUse only factory replacement
CMC1Use only factory replacement
L1Use only factory replacement
Fuse PCBUse only factory replacement*SeeServiceBulletin(INF2000-01 REV 2)page15.
Main PCBUse only factory replacement
R29470W .25W METAL OXIDE, non flammable
IMPORTANT SERVICE NOTES: When testing the BU120/HTS-20 Series amplifier, a load must always be
2connected to the output terminals, whether the woofer, or a 4 to 8 ohm resistive load.
All AC powered test instruments (meters, oscilloscopes, etc.) must have a floating ground, i.e. be
connected to an isolation transformer. |
ACEC
HARMAN KARDON
