Might need a new cold inlet valve fitted oe maybe no power getting to turn the valve on. First take cold hose off machine, point the end in to the sink & turn tap on slowly to make sure there is a good strong flow. Check filter inside inlet valve before you screw hose back on to make sure it is not blocked. After that you will need a multimeter to test the valve & the power supply. I assume you don't have one so you will need to call out a service person.
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