Roland BOSS RT-20, Service Notes

18

Dec. 2005

RT-20

11. DSP Route FET Switch Working Check

1.

Press the right pedal to start the 

DSP Route FET Switch Working 

Check

.

fig.11-DSPSW-panel

2.

Confirm the output wave disappears and be like the following picture.

fig.11-DSPSW-1_70(200 mV/DIV, 1 ms/DIV)

12. Bypass Route Residual Noise Check

1.

Press the right pedal to start the 

Bypass Route Residual Noise Check

.

fig.12-BYPNOISE-panel

2.

Connect the 47-k

Ω

 short plugs to INPUT A (MONO) and INPUT B.

3.

Connect the noise meter to OUTPUT A (MONO) and measure the 
residual noise.

Passing Value:

-91 dBu or less (JIS-A)

4.

Connect the noise meter to OUTPUT B and measure the residual noise.

Passing Value:

-91 dBu or less (JIS-A)

5.

Connect the noise meter to PHONES (L, R) and measure the residual 
noise.

Passing Value:

-91 dBu or less (JIS-A)

6.

Connect monitor speakers to OUTPUT A (MONO) and OUTPUT B.

7.

Give a shock (hard vibration) to the RT-20’s body, and confirm any 
abnormal noise are not generated from OUTPUT A (MONO), OUTPUT B 
or PHONES (L, R).

13. DSP Through Route Residual Noise 

Check

1.

Press the right pedal to start the 

DSP Through Route Residual Noise 

Check

.

fig.13-DSPNOISE-panel

2.

Connect the noise meter to OUTPUT A (MONO) and measure the 
residual noise.

Passing Value:

-84 dBu or less (JIS-A)

3.

Connect the noise meter to OUTPUT B and measure the residual noise.

Passing Value:

-84 dBu or less (JIS-A)

4.

Connect the noise meter to PHONES (L, R) and measure the residual 
noise.

Passing Value:

-84 dBu or less (JIS-A)

5.

Connect monitor speakers to OUTPUT A (MONO) and OUTPUT B.

6.

Give a shock (hard vibration) to the RT-20’s body, and confirm any 
abnormal noise are not generated from OUTPUT A (MONO), OUTPUT B 
or PHONES (L, R).

14. Battery Working Check

1.

Remove the AC adaptor to turn off the power.

2.

Put batteries into the battery box and connect a plug to INPUT A 
(MONO).

3.

Check the 

POWER

 LED lights.

200mV/DIV, 1ms/DIV