ALLEN & HEATH GL 2000, Руководство по обслуживанию

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ALLEN & HEATH
Section C - 3 L2dSM2
SPECIFICATION
AC MAINS INPUT: 100V, 110V, 120V, 220V, 230V or 240V @ 50Hz to 60Hz single phase
POWER CONSUMPTION: 60VA
DC OUTPUT: +48V @ 100mA, +/- 16V @ 0.8A per rail. (GL2000-424)
NOISE & RIPPLE: < 2mV max (peak to peak)
SERVICE ACCESS
Any fault condition, with the exception of simple mains fuse failure due to underrating or an unusual mains input
condition, will require removal of the base cover to enable correction of the fault. This is achieved using a cross-head
screwdriver to remove all of the base screws which are positioned along the edges of the base. Do not forget to remove
the two screws in the centre rear of the base.
Carefully lift the cover and place it to one side. The power supply sub chassis can then be removed by unsrewing the
2 mounting screws (A) in the console rear panel and the 2 fixing screws (B) in the sub chassis base next to the PSU
circuit board. Take care not stretch the wires connected to the console.
Servicing Components
All of the regulators are in TO220 packages. To replace them, it will be necessary to remove the power supply circuit
board assembly with the heatsink attached. Refer to the L2D PSU assembly diagram 002-150.
1.) Remove the 4 PCB mounting nuts (C) and 2 heatsink fixings (D).
2.) Carefully lift the heatsink and PCB assembly clear of the PSU sub chassis and unscrew the screw and nut
of the regulator IC that requires replacing. Take care to retain the small insulating bush beneath the head
of the screw and the insulating SIL pad under the regulator.
3.) Rotate the assembly to gain access to the solder side of the PCB and desolder the three terminals attached
to the regulator. The regulator can now be removed.
4.) Fit the replacement regulator by first fixing it to the heatsink using the screw and nut and then soldering the
three terminals to the circuit board. Make sure the insulating SIL pad and bush are fitted. The metal tab at
the top of the package is electrically connected to the centre lead and correct insulation is essential. If the
insulating SIL pad between the regulator and the heatsink looks damaged then it should be replaced before
installing the new regulator. Note that the regulators rely on good thermal contact with the heatsink to
dissipate heat, and this is provided by the SIL pad.
5.) Reassemble the circuit board and heatsink assembly into the power supply sub chassis. Check your work
and remove any debris from the sub chassis before refitting it to the console.
CAREFULLY CHECK ALL WIRING CONNECTIONS AND ENSURE THAT THERE ARE NO LOOSE
PARTS LYING AROUND INSIDE THE CONSOLE.
console inverted with the base removed
A
A
B
C
C
D
B
D