my hp designjet is showing this error, system error 1120,

i replaced the vacuum fan on the wiping station side but still the

error code is not resolved.

it seemd only two of the vacuum fans on the centre platten(J 20-2,J20-3)

starts to work but stops shortly.

there is also a led flashing on the main pca.

IS THE MAIN PCA FAULTY ? or

Can someone please help me?

Thanks