Hello folks, I am hoping someone has an idea on what is going on with my AVIC-Z1

I have the bypass in place and have been using my AVIC-Z1 unit since 2008.

Unit was upgraded with a Toshiba MK6034GAX drive and the Z3 2010 Maps

Everything has worked perfectly for years since the upgrade, however last week I started getting "Cannot use HDD" error messages.  They seemed sporadic and would go away sometimes.  Finally on start they became permanent, so I figured I have a bad upgraded HDD.  I pulled it and ran diagnostics.  All good, nothing wrong with it.  

As a test I took the original 30GB Toshiba HD the unit came with and put it in.  Same Result:   "Cannot Use HDD"

At this point I am thinking there is an internal issue with the unit as the original HD should have worked, no?

Thoughts/Suggestions?

I would concur.  The original HDD should always work as long as it originally came from that particular Avic.  You can't swap original drives between multiple Avics unless it is unlocked.  You may just have a loose internal IDE cable.

What does this IDE cable connect to?  The HDD housing?

Any pics?