Yes, the FCV588 is the exact foot print if you decide to upgrade.
I would recommend sending the unit into our service center for repair evaluation.
You would send the unit to the Furuno Repair Facility with a detailed description of the problem. No RMA number or initial payment is required. Please make sure to include your contact information. The address is listed below for your convenience.
Furuno USA, Inc
Attn: Service Department
4400 NW Pacific Rim Blvd.
Camas, WA 98607-9408
The Service Center will contact you concerning cost and billing after the unit has been evaluated.
The Service Center has a $100 evaluation fee for out of warrantee items, but they will apply that towards the repair cost, if you choose to have it repaired. Repair time can vary depending on work load and season. Mostly 7-10 business days plus postal time. If you need to contact our service center they can be reached at 360-834-9300. (ask for the service center)