Power On Sequence - TC Electronic G-Force Service Manual

Power On Sequence

The table below shows the Power On Sequence for main board version PC13002-2, when the G-Force is switched on by using the power switch at the back panel. Equal sequence numbers mean
that the events are independent of each other. The column named Trouble Shooting has hints about what to check if the event fails.
No Event
1a SB_VCC (POWER_SB, Violet wire) goes to approx. 5VDC and supplies IC1.
1b +15V (POWER_+15V, Orange wire) goes to approx. +15VDC.
1c -15V (POWER_-15V, Yellow wire) goes negative to approx. -15VDC.
2 TP4 goes to +4.7VDC. C8 is discharged and keeps IC1 pin 13 low and subsequently
IC1 pin 8 goes high.
3a +5VSB, (+5V_STANDBY*, Brown wire) goes to approx. +3.2VDC
3b Q1 and Q2 turns on IC2
3c Standby LED is lit
4a +5V (POWER +5V, Red wire) goes high.
4b TP1, -15V starts up.
4c TP2, +15V starts up.
5a Display backlight turns on
5b IC9 pin8, CPU clock starts up, 14.112MHz
5c IC27 pin2+3+6+7, power for PLL, goes high.
5d TP68, 256FS starts up
5e LD4 turns on.
5f Q8 emitter, +5VA (+5VAD) starts up.
5g IC37 pin2, +5VA (+5VDA) starts up.
5h TP3, rises to +3.3V .
6a TP8, DSP clock starts up, 44.100KHz
6b TP70, ADA_64FS starts up (2.822MHz)
6c TP72, ADA_1FS starts up (44.1KHz)
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TC Electronic A/S
Trouble shooting
Power cord, DZ1, IC1 or power supply.
power supply, load (normal current load is approx. ?mA)
power supply, load (normal current load is approx. ?mA)
IC1, DZ1
R7
Q1, Q2, IC2
Q1, Q2, IC2
power supply, load (normal current load is approx. ?A)
IC2
IC2
Ribbon cable at Front connector J1, two solderings at display for back light.
IC9, X1, (unstable until clean power comes from IC27)
IC25, IC27
IC9, IC28 + soldering, If CPU clock is missing the frequency is undefined.
IC33. NOTE: If IC35, 36 or 41 are defective they can turn LD4 off via IC33 !!
IC26, Q8
IC37
IC42
IC24 + soldering
IC24 + soldering
IC24 + soldering
G-Force Service manual page 13