This isn't a laptop. It's a portable 12MHz 286 PC from 1987 with 1MB RAM, 40MB hard drive, 3.5-inch floppy drive, an orange plasma screen and two expansion slots in the base.
Info here: http://www.computinghistory.org.uk/det/4435/Toshiba-T3200/
Photos of someone else's here: https://www.flickr.com/photos/anachrocomputer/8572852576/
I bought this via Trade Me based on the previous seller's description and thinking that the problem might just be a CMOS battery error. But it's not - I've removed the CMOS battery (no leakage). There's something else wrong. I'm not sure what, but I do have a theory.
Sometimes when switching it on the screen will stay blank but all the LEDs will stay on. Other times the screen will work and the machine will complain 'ERROR CMOS CHECKSUM' and go no further. Sometimes it will get past that point and give a keyboard error, sometimes a memory error...
But at other times it will boot through to the BIOS screen, complain about checksums, allow me to 'Press F1 to continue' and then start the boot process. The furthest I've managed to get so far is 'Starting MS-DOS...' (so I guess that's MS-DOS 6.xx?) before it locked up, but that may have been due to the wrong hard drive being defined in the BIOS (i.e. it read the MBR but didn't get much further).
So I think the screen, the hard drive, floppy drive, RAM, keyboard, etc. are actually all fine. What's wrong is at the system level.
I have the PDF for the service manual and it talks about checking the output voltages from the PSU. I don't really feel like dismantling this to find out, but my theory is that the voltage to the motherboard is a bit low, which leads to random logic errors. Depending on when in the boot cycle those errors occur, the boot process fails at a different point. Maybe a damaged capacitor or something? I don't know enough to be sure, so I'd probably do more harm than good if I pulled it apart.
It's a lovely, clean machine complete with original Toshiba carry case and I dearly want it to work because the orange plasma screen is great and the keyboard is a delight. The only missing part is a plastic wheel for the brightness control, but the contrast one is still there and the screen works fine.
The previous seller said the PC was working recently, so this is apparently a new problem. There are no funny smells, no smoke, no burning. I don't think the problem is a terminal one.
I paid $100, i.e. too much, though these go for more than that on eBay in a broken state and considerably more when working. It's probably worth more in parts.
My preference would be to get it working and keep it. My second choice would be to sell it and get at least some of the purchase cost back (and take this as a lesson to test things in person before buying).
Any ideas, thoughts, offers?