Hey everyone,
I'm hoping someone here has access to the schematic or boardview for this specific board, or has dealt with the same failure before. I've searched pretty hard and this exact board number doesn't seem to be floating around anywhere, paid or free.
The machine: Toshiba Satellite L70-B, model PSKS8E-00K004TE. i7-4710HQ, 8GB DDR3, switchable graphics — Intel HD 4600 + AMD Radeon R9 M200X (the AMD chip is marked 216-0846009 on the die). Board is Inventec, silkscreened AR10SQG / AR10CQG, part number 6050A2640401-MB-A01. BIOS is Insyde, v5.20.
What happened: I went into BIOS setup and switched the boot mode from UEFI to Legacy/CSM, saved with F10, and the system never showed video again. Not the internal panel, not HDMI, not VGA — completely dead on all outputs, even though the machine still powers on normally and the fan kicks in after a minute or two.
What I've tried so far:
Full reflash of the BIOS chip with a CH341A programmer, using a stock dump (same result, no change).
Full CMOS/battery drain, waited well past 10 minutes, reassembled — no change.
Tested with a single RAM stick, in both slots, both sticks — no change.
Caps Lock LED doesn't respond at all when I hit the key, from the very first time it happened.
CPU heatsink gets noticeably hot within the first minute of being powered on, which feels excessive for a machine that's just sitting at POST doing nothing.
I did later (after all of the above, as a last resort) reheat the AMD GPU with a hot air station to see if it would help, no change either — so I don't think the reheating caused the original fault, though it's possible I made things worse.
I actually found a thread here where someone else hit the exact same symptom on this exact board after the same UEFI→Legacy switch, and the only reply was "please use UEFI," with no actual fix given. So this doesn't seem to be a one-off mistake on my end.
At this point I'd really like to get hold of the schematic or boardview to actually measure rails and trace where the hang is happening, rather than guessing. I've got a proper bench setup (multimeter, hot air rework station, microscope, SPI programmer) so I can do real diagnostic work if someone can point me to the files, or if anyone has personally dealt with this board and can tell me where to start probing.
Appreciate any help, even if it's just "I've seen this exact failure, here's what it turned out to be."
I'm hoping someone here has access to the schematic or boardview for this specific board, or has dealt with the same failure before. I've searched pretty hard and this exact board number doesn't seem to be floating around anywhere, paid or free.
The machine: Toshiba Satellite L70-B, model PSKS8E-00K004TE. i7-4710HQ, 8GB DDR3, switchable graphics — Intel HD 4600 + AMD Radeon R9 M200X (the AMD chip is marked 216-0846009 on the die). Board is Inventec, silkscreened AR10SQG / AR10CQG, part number 6050A2640401-MB-A01. BIOS is Insyde, v5.20.
What happened: I went into BIOS setup and switched the boot mode from UEFI to Legacy/CSM, saved with F10, and the system never showed video again. Not the internal panel, not HDMI, not VGA — completely dead on all outputs, even though the machine still powers on normally and the fan kicks in after a minute or two.
What I've tried so far:
Full reflash of the BIOS chip with a CH341A programmer, using a stock dump (same result, no change).
Full CMOS/battery drain, waited well past 10 minutes, reassembled — no change.
Tested with a single RAM stick, in both slots, both sticks — no change.
Caps Lock LED doesn't respond at all when I hit the key, from the very first time it happened.
CPU heatsink gets noticeably hot within the first minute of being powered on, which feels excessive for a machine that's just sitting at POST doing nothing.
I did later (after all of the above, as a last resort) reheat the AMD GPU with a hot air station to see if it would help, no change either — so I don't think the reheating caused the original fault, though it's possible I made things worse.
I actually found a thread here where someone else hit the exact same symptom on this exact board after the same UEFI→Legacy switch, and the only reply was "please use UEFI," with no actual fix given. So this doesn't seem to be a one-off mistake on my end.
At this point I'd really like to get hold of the schematic or boardview to actually measure rails and trace where the hang is happening, rather than guessing. I've got a proper bench setup (multimeter, hot air rework station, microscope, SPI programmer) so I can do real diagnostic work if someone can point me to the files, or if anyone has personally dealt with this board and can tell me where to start probing.
Appreciate any help, even if it's just "I've seen this exact failure, here's what it turned out to be."
