GS7328Sv2 Reboot-loop and I/O Module Issues

Hello, first time poster here.

I have a GSM7328Sv2 with multiple issues.  The most pressing is that I have somewhat "bricked" my switch in an effort to figure out why my newly installed AX743 modules aren't working correctly.

I have been running 10.0.0.54 firmware for some months now with no issue.  After installing my 2 (used) AX743 modules, I can not get them to work with any SFP+ modules or DACs, including the OEM Netgear AXM761 SFP+ modules.  All of the modules I tried work fine in the built-in 10G ports.

With 3 DACs and 1 Netgear AXM761 populating the 4x 10G ports: (note, the AXM761 and DAC in the front were working when this command was issued)

(GSM7328Sv2) #show fiber-ports optical-transceiver all

No SFP(s) / Fiberport(s) available

(GSM7328Sv2) #show fiber-ports optical-transceiver-info all

No SFP(s) / Fiberport(s) available

I had already went into Stacking to disable the rear IO ports stacking and set them up as Ethernet already.  Interestly, though, the switch thinks these modules are the 10GBaseT models (AX745): (Note: at this point, there was only the AXM761 module installed, although it still shows as DAC for some reason)

(GSM7328Sv2) #show stack-port

                                                Configured Running
                                                Stack      Stack      Link       Link
Unit    Interface     Type    Product Name      Mode       Mode       Status     Speed (Gb/s)
---- ---------------- ------- ----------------- ---------- ---------- ---------- ------------
1    0/25             DAC    Ethernet   Ethernet   Link Down    10
1    0/26                                       Ethernet   Ethernet   Link Down    10
1    0/27             AX745   (ax745)           Ethernet   Ethernet   Link Down    10
1    0/28             AX745   (ax745)           Ethernet   Ethernet   Link Down    10

Thinking maybe it's a firmware issue, I opted to activate the firmware image that was on the switch when I received it, which was an 8.0.x.x version.  Upon reboot, the unit became inaccessible and generally resets itself every 1-2 minutes.  I removed the I/O modules and this didn't help.  I unplugged every cable and this sometimes helps.  At this very moment, the switch is running and not self-resetting, however it is inaccessible on any IP address or through any port.  I had tried a factory reset with the RST button on the front using various methods (held for 5 seconds while powered on, hold 30 seconds powered on, hold 30 seconds power off, etc.).  I can't find any specific way to factory reset the switfch using this button in any manuals.

Does anybody have any advice on what to do next to 1) get the switch accessible and 2) get these I/O modules working correctly?

FYI, I have no serial cable but I just ordered a crossover cable last night from Amazon.  It'll be a few days before it arrives though so I'll try anything else in the mean time.  I'll also be happy to get instructions for what to do once attached to serial console to get the switch online if nothing else works.

Thanks in advance.