Roland BOSS RT-20, Service Notes

13

Dec. 2005

RT-20

Checking the Version 
Number

Enter Test Mode and execute “

1. CPU, DSP Check

” and “

2. Version Check

” 

in this order.

About Updating

Exchange the circuit board for updating of system program. Follow the service 
information when it’s needed. 

Test Mode

Test Items

1. CPU, DSP Check

2. Version Check

3. Knobs Check

4. DRIVE TYPE Switch Check

5. Expression Pedal Check

6. Analog Bypass Waveform Check

7. Analog Bypass Route FET Switch Check

8. D/A Output Waveform Check

9. DSP Through (Output) Waveform Check

10. DSP Through (PHONES) Waveform Check

11. DSP Route FET Switch Working Check

12. Bypass Route Residual Noise Check

13. DSP Through Route Residual Noise Check

14. Battery Working Check

Items Required

• Monitor Speaker

• Expression Pedal (EV-5)

• Noise Meter

• AC Adaptor (PSA series)

• 47-k

Ω

 Short Plug x 2

• Oscilloscope

• Oscillator

Entering Test Mode

1.

Rotate all of the eight knobs on the top panel counterclockwise fully.

2.

While holding down the left and right pedals, connect the AC adaptor.

3.

When the POWER LED lights, release the both pedals.

4.

Press the left pedal within 2.5 seconds, then press the right pedal.

When the blue LEDs light, you will enter the Test Mode, and 

1. CPU, DSP 

Check

 is executed automatically.

Exiting Test Mode

Turn off the power.

Skipping

If you set the 

MODE

 knob previously as follows before entering the Test Mode, 

you can specify the start point of the Test Mode.

MODE knob I:

from 

1. CPU, DSP Check

 (normal Test Mode)

MODE knob II:

from 

6. Analog Bypass Waveform Check

MODE knob III:

from 

8. D/A Output Waveform Check

MODE knob VI:

from 

12. Bypass Route Residual Noise Check

1. CPU, DSP Check

 will be always executed irrespective of the MODE knob’s 

setting first. And next, when the right pedal is pressed, you will enter the test 
item corresponding to the MODE knob’s setting. You can confirm which test 
item you entered by checking the Virtual Rotor Display. (Refer to the 
explanation of each test item.)

Any test item can be skipped by pressing the right pedal (SLOW/FAST pedal). 
However, the test item 

3

, 

4

, and 

5

 can be skipped.

Details for Tests

1. CPU, DSP Check

After entering the Test Mode, first, CPU and DSP will be tested. If they are 
normal, two blue LEDs in the Virtual Rotor Display will light as the following 
picture.

fig.01-cpudsp

If there are any problems, you cannot advance to the next test item. Then turn 
off the power to finish the Test Mode.

2. Version Check

1.

Press the right pedal to start the 

Version Check

.

Version is shown in the Virtual Rotor Display as the following picture.

fig.02-cpuver

Ver. 1.00

Ver. 1.01

Ver. 1.02

Ver. 1.03