Altronics K 5171 Podręcznik - Strona 9

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K 5171

Qty.

Value

1MΩ

100kΩ

22kΩ

18kΩ

12kΩ

10kΩ

2.7kΩ

2.2kΩ

1.8kΩ

1kΩ

330Ω

100Ω

22Ω

10Ω

Adjusting trimpot VR2

Next, set the volume control to mid-position,

set VR2 fully anti-clockwise and hit the Mute

button. The pot will rotate anti-clockwise and

as soon as it hits the stops, the clutch will

start to slip.

While this is happening, slowly adjust VR2

clockwise until the motor stops. Now press

Volume Up to turn the potentiometer clock-

wise for a few seconds and press Mute again.

This time, the motor should stop as soon as

the pot reaches its anticlockwise limit.

A programmed time-out of 13 seconds will

also stop the motor if it continues to run after

Mute is activated. This means that you have

to adjust VR2 within this 13s period. If the

motor stops prematurely or runs for the full

13s after the limit is reached, try redoing the

adjustment.

Troubleshooting

If the unit fails to respond to remote control

signals, check that the remote is in the cor-

rect mode (TV, SAT1 or SAT2) and has been

correctly programmed.

If you're using a remote other than those

listed in the panel, work through the different

codes until you find one that works. Start with

codes listed under the Philips brand as these

are the most likely to work.

If the unit responds to the 1, 2 & 3 buttons

on the remote but the button switches don't

work, check that the ribbon cable to the

pushbutton board has been crimped properly.

Similarly, if the remote volume function works

but not the remote input selection, check the

cable from the Preamplifier board to the input

selector board.

Note that the cable from the Preamplifier

board also supplies power to the other two

Resistor Colour Codes (all three PCBs)

4-Band Code (1%)

brown black green brown

brown black yellow brown

red red orange brown

brown grey orange brown

brown red orange brown

brown black orange brown

red violet red brown

red red red brown

brown grey red brown

brown grey black brown

orange orange brown brown orange orange black black brown

brown black brown brown

red red black brown

brown black black brown

boards. So it's worthwhile checking that there

is 5V between pins 8 & 4 of IC4 on the Selec-

tor Board and again check the ribbon cable if

this supply rail is missing.

Audio testing

If you are using a ±15V supply for testing, you

can test the preamplifier further by con-

necting its outputs to a stereo amplifier and

feeding in audio signals from a mobile phone,

tablet, iPod, CD/DVD/Blu-Ray player or just

about any other source.

Depending on your device, you may need a

cable with a 3.5mm stereo plug at one end

and red/white RCA plugs at the other end to

make the connection. These are commonly

available.

ULTRA LOW DISTORTION PREAMPLIFIER WITH TONE CONTROLS

5-Band Code (1%)

brown black black yellow brown

brown black black orange brown

red red black red brown

brown grey black red brown

brown red black red brown

brown black black red brown

red violet black brown brown

red red black brown brown

brown grey black brown brown

brown black black brown brown

brown black black black brown

red red black gold brown

brown black black gold brown