IQ4 Panel - Unresponsive/No LEDs/Blackscreen

Support,

I am trying to switch my service from ADT to Surety for an IQ Panel 4 in a home purchasing. That said, the IMEI is unlocked and I have purchased service through Suret and done the Alarm.com set ip, but I have an unresponsive black screen with no LED flashes at all. I feel it is important to share that the panel unplugged for a very long time, maybe one year, but has been plugged in using the 7V power supply for about a week. Today, as part of the Alarm.com set up I went to the panel and tried to turn it on. Here is what I know & observe:

Powering on with the power button led to no LED activity/flash no light coming from the screen.

Panel is unresponsive to holding the home/power button for 30 seconds.

Full power cycle disconnecting the battery for 5+ minutes, plugging it back in and holding the power button for 3 seconds still gives a blackscreen.

I disconnected the battery and power supply for 5 mins+ and did the following:

Unplug the battery, unplug the AC power.

Reconnect the battery only.

Insert AC power plug, wait 5 seconds and then remove.

Repeat this up to 10 times but the LEDs and the screen remained unresponsive.

Thanks in Advance!