Do Arahants have Vinnana and Namarupa? Do Arahants have Vinnana and Namarupa?
According to Dependent Origination, Namarupa is the result of Vinnana. It appears Vinnana is the contributory factor for six sense base which eventually leads to rebirth. Hence Arahant will not be re-born then the question come whether they have Vinnana and Namarupa.
First of all, it is incorrect to say "arhats have vijnana (etc)". The word "have" implies someone who has, but in case of an arhat there's no entity, no one to "have" vijnana. The right way to phrase this question is to say: In case of an arhat, are there vijnana and namarupa?"

Second, an arhat will not be reborn exactly because there is no entity to be reborn, and this realization is part of cessation of ignorance which normally keeps the Twelve Nidanas rolling.

Third, in this context vijnana and namarupa refer to nidanas, not to skandhas. The twelve nidanas describe the process of gradual taking shape and hardening of a certain subjective world and the person living in it. Vijnana and namarupa refer to early stages of this process. First, there develops a tendency to recognize and discriminate, and from that tendency appear various objects and entities. That's what vijnana and namarupa refer to in context of twelve nidanas. They refer to the naive, ignorant discrimination and to the illusory entities that it delineates.

In case of an arhat, the discernment is no longer ignorant and it therefore does not posit illusory entities. Buddha clearly said, with cessation of ignorance, there's cessation of tendencies, with cessation of tendencies there's cessation of vijnana etc. This refers to cessation of naive, ignorant automatic discrimination which contrives objects and then believes they are absolutely ontologically real.

So we are not saying that the skandhas disappear with attainment of arhathood, not at all. Arhathood is cessation of nidanas, the causal chain that leads to emergence and hardening of the illusory world and the illusory self.  

And of course arhats are not mindless dummies. In case of an arhat there's a function of right discernment. This function is called prajna. The object of this discernment is yatabhuta, things as they truly are. This refers first and foremost to seeing samskaras as samskaras, instead of the fixed entities. Because samskaras are seen as samskaras, they are seen as Anicca, Dukkha, Anatta, and at Mahayana level, as Shunya. 

So the short answer is, no, in case of an arhat there's no vijnana and namarupa - there's prajna and samskara/shunyata.