CRTU: Repair/Calibration

[Bicurico]

Hi,

The CRTU I received fails on some tests.
For instance, on the Internal RF Loop Test, about half of the values are off tolerance, for example:

1->1 Ok : 2200.000 M, Bd.4, Exp. -73.0 dBm, Meas. -82.9 dBm

Is this configurable? An error? Something broken?

Sometime an error message says "Reference Board Not Locked" (or something similar, it flashes quickly).

Is there any point in extracting each module, opening it up for just cleaning purposes?
Is it normal that the modules look worn out/oxidized on the outside?

Regards,
Vitor

[mjs]

Have you configured the CRTU to use the internal reference from the settings ?

The modules are probably silver plated and look oxidized outside - there's no point in opening them

If you want to see what's inside, see my pictures at https://www.dropbox.com/sh/zgwzbpt91o9p1it/AACC-1YIhZs6Y-2iTAEGV1kCa?dl=0

[Bicurico]

I am currently waiting for a second (broken) unit and hopefully I can assemble a working one out of both. Until then I will refrain from opening what so ever...

Thank you for the great pictures!


Regards,
Vitor

[CJay]

There most definitely is a point to opening them, those connectors on the 'protocol board' in the Dropbox pictures are the reason why.

They're used for additional hardware options in a few of the modules and the connections on those option boards oxidise.

On my CMU cleaning those connections resulted in a working machine.

YMMV of course but I would say it's worth looking into.