TAG MCLAREN AUDIO 100 5R Series, Руководство по обслуживанию

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F3 series 100X5R service manual 13
Fuses should not blow in normal use. A blown fuse is probably an indication of a more serious
problem. Before replacing the fuse check that the circuit it is connected to is not a short circuit. If it is
this will need to be corrected first.
A short circuit in the transformer primary windings could cause the mains fuse to blow. With the mains
lead removed and the unit power switch in the on position use a multimeter to check the primary
resistance across the terminals of the IEC mains input connector. The resistance should be approx
240 Ohms for a 230 V unit or 48 Ohms for a 100/115 V unit (the impedance for the individual module
transformers is 5.5 Ohms for a 230 V unit or 1.2 Ohms for a 100/115 V unit, but these are isolated
from the IEC inlet when the power is off. These points can be accessed from the microcontroller PCB
inside the unit). If it is much less than this then either the transformer or the input wiring has
developed a short circuit. Correct the wiring or replace the transformer as necessary.
4.2.6 Connect AC Switch on power button
power to unit
4.2.7 Unit powers up LEDs light and module relays
switch in sequence
4.2.8 Unit un-mutes After settling time module mute
relays close and mute light goes
out.
4.2.9 Power out DC
<±2mV
4.2.17 Gain I/O 28.8dB ± 01dB
4.2.18 Check uC Multimeter set Connect negative probe to 0 V,
supply rails to V DC eg chassis
Connect positive probe to
5 V rail
(TP52) .
Voltage should be 5 ± 0.3 V.
4.2.19
4.2.21
5.4 Biasing Modules
If a module is to be replaced or repaired, where the repair affects any part of the amplification section, the bias
on that module will need to be re-calibrated. The bias voltage across the emitter resistor (R61) is accessible
via J1. The bias voltage takes some time to settle so the following proceedure is recommended:
1 With the lid removed, switch on the 100x5R.
2 Set the new/repaired module bias to ~100mV for 20mins with the lid upside down on the top of the
unit to ensure similar air flow through the unit. This will rapidly bring the module to quiescent
temperature.
3 Set the bias to 23mV ±0.5mV.
4 Leave to soak test overnight, then set the bias to the same as the adjacent module, ±0.5mV.
The module should be set to the same reading as a factory set unit for best results.