virus ti desktop won't boot

[eflister]

i have a virus ti desktop that has never had issues and worked fine last time i turned it on.
it's sat a few months untouched, attached to a surge protector. when
i went to turn it on today, i just get the backlight of the screen,
but it's blank and doesn't respond to anything (MIDI IN, buttons,
knobs).
if i unplug it and plug it in while holding:
TAP+CONFIG (supposed to pull up serial number/diagnostics), i get the
same blank screen.
ARP EDIT: same blank screen, but BPM and LOGO LED's go back and forth,
that's it.
EXIT: same blank screen, BPM LED fades in and out.

i've tried connecting via usb to the virus software on my computer,
but it shows no virus detected.

i am seeing a bright orange spark about 5mm across when i connect the
AC adaptor, maybe once every 2-3 times i plug it in. not sure if that
was there before.

the manual says you have to use the original AC adapter, but i'm wondering if it's worth trying a different one with the same specs?

i've tried emailing access and didn't get the automated reply they said i should expect. the closest service center they list is a couple states away. i wrote to them and they said they'd need me to ship it to them.

anyone have any experience with something like this or recommendations? thanks for your help!
-erik