Barcrest Hit The Top communication error

[briperk1]

Hello all,

I recently acquired a Hit The Top S+ Barcrest and it immediately displays an H_04 when powered on.  The machine powers on and the reels spin like they should, the insert coin lights up, and no error is displayed on the lower part.   The Barcrest unit eventually will display a C_01.  Based on the reel positions, it must have hit the bonus feature and then failed.  The red and green LED's on the interface board are not on.  It will let me cycle through the test features but I get no sound on the sound test.  I have re-seated all the connectors on the backplane and on the barcrest unit.  Machine MPU and Backplane look really clean, however the Barcrest MPU4 does have some damage from the Varta Battery.  I have since removed it.  Does anyone here test and repair the Barcrest MPU's?  Also, the harness that runs between the interface board and the machines backplane looks a bit suspect to me.  It has another small PCB in the middle that is wrapped in tape and one of the two connectors at the backplane is a 3 pin connector plugging into a 4 pin connector on the backplane.  Is there anything else that i may be missing?  Ive successfully resurrected several S+ machines so I'm pretty familiar with the S+, but as you know this is a bit different.