Problem: screen. First step: check it with an external display. Then we know everything else is working OK, but that the screen is definitely a problem.
message from Graham: power light but no screen
power drain didn’t solve anything
check it with external display first if possible
nothing on external display
HP 655 / B6M63EA
Processor Speed 1.4 GHz
2Gb RAM
AMD 1400 MHz
Portable Radeon HD 7310
Item model number B6M63EA#ABD
Series 655 B6M63EA
Item Weight 2.5 Kg
Form Factor Portable
Screen Size 15.6 inches
Processor Brand AMDยฎ
Processor Count 2
RAM Size 2048 MB
Computer Memory Type DDR3 SDRAM
Hard Drive Size 320 GB
Hard Disk Technology HHD
Graphics Chipset Brand AMD
Graphics Card Description Radeon HD 7310
Wireless Type 802.11b, 802.11g, 802.11n
Number of USB 2.0 Ports 3
Supported Software Microsoft Office 2010 Starter
Average Battery Life (in hours) 5 hours
Lithium Battery Packaging Batteries contained in equipment
OK, which one? One where the screen appears fine, but something else is busted. Doesn’t need to be high resolution.
https://hackernoon.com/https-medium-com-akshaykore-diy-monitor-410ac3bbb6b9
https://www.instructables.com/id/How-to-Convert-a-Laptop-LCD-into-an-External-Monit/
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