Recall factory preset #3 to be sure that you have the same routing and settings in both channels when testing.

(Input ch1 routed to Output ch1, input ch2 routed to Output ch2)
(You will still have to set the input settings manually on the front).

Naturally, you should also use the built-in selftest.

Please note the bug in software lower than v.1.10:
Self test: Accepted limits in the analog self-test were set incorrect, causing the self-test to report faults even at OK functioning hardware.

We recommend that the MicAmp version 3 PCB is replaced by version 5 unless the version 3 PCB is fully updated (according to service note 72010T035, 72010T034 and 72010T036)
TC order code: 720016511 - Gold Ch. Mic. Amp. service PCB v.12905-5

Quick noise measurement using the input meters:

1. Disconnect input cables,

2. Set Meter to show input,

3. Set Input gain to max, fully clockwise,

4. Set Pad to 0dB(+48V, Lowcut, Softlim, Phase: disabled)
5. Input meter should show max. -40dB, higher readings indicate a broken/noisy MicAmp board.