820-01958 20v, backlight, no image

[Outofwhack]

No liquid history, no corrosion visible
Backlight comes on but no logo
CPU gets hot
Tried known good screen
SSD0 Voltage rails 2.5v, .8v, 0.9v all present.
No toggle of caps lock light
No external video
No USB activity

DM on pins J8500 1,3 .36v, .36v