Sony Vaio PCG-F807K/F808K/F809K

I bought these two laptops; a PCG-F807K (sold as working) and a PCG-F809K (sold as non-working) in January 2025 as potential candidates for a top-end DOS gaming laptop, to compare with the Thinkpad 240, which whilst a great machine, is not quite perfect (mono sound, less-than-perfect scaling of low res games).

PCG-F809K

PCG-F807K

• Intel Pentium III Mobile
  • 650MHz - F807K
  • 750MHz - F808K
  • 850MHz - F809K
• 256MB (maximum) PC100 SO-DIMM (2x slots)
  • 64MB (standard) - F807K
  • 128MB (standard) - F808K/F809K
• ATI Rage Mobility M1 8MB
  • 14“ 1024×768 TFT screen - F807K
  • 15” 1024×768 TFT screen - F808K
  • 15“ 1400×1050 TFT screen - F809K
• Yamaha YMF-744 audio (OPL3, SB Pro 2.0, XG MIDI - Windows only)
• 2x PCMCIA / Cardbus
• Headphone out, Microphone in (no Line-in)
• Stereo speakers
• Onboard FDD + DVD

These models are also referred to as PCG-9326, PCG-9336 and PCG-9316.

• Sony PCG-F807/808/809K User Manual

It appears that all Sony Vaio PCG-Fxxx series laptops share a similar construction, and the same BIOS/CMOS battery. It is tucked under the wrist rest at the front of the machine, just in front of the FDD bay, and to the right of a power controller board / laptop lid sensor board.

Unfortunately all of these batteries are Ni-Mh cells and they all leak.

On severe cases the leaking cells can cause severe corrosion to the case, FDD, power board and lid sensor, rendering all of them inoperable.

Please replace these batteries as soon as possible. They are present on virtually all Sony Vaio PCG-Fxxx models, and likely others, too.

Somewhat related to the leaking batteries, but also an independent issue even for laptops with no battery leakage, is the power sub-board.

This board is at the front of the case, central between the left side battery bay and the right side FDD bay, under the front of the keyboard/wrist rest. It interfaces with both battery modules (the standard left hand bay, and the optional extra battery in the FDD bay) as well as the main power from the 19.5V DC jack on the rear of the machine.

The laptop will not operate without this small board, even if you do not use the laptop battery pack!

Unfortunately, there seems to be some inherent problem with this board where it dies due to age or use, as well as being damaged by battery leakage. In two seperate examples I found the power board had no additional damage from battery leakage other than slight discolouration of the two pins for the CMOS battery header. No visible corrosion anywhere else, no damaged traces, no broken components. Yet neither board would allow the laptop to power on.

A third board, from a known-working (PCG-F807K) laptop was transplanted in (to a PCG-F809K), and despite looking identical, with the same level of minor battery damage to the CMOS battery header pins, actually allowed the second machine to work.

So, two possible failure modes for this power board:

• Failure due to corrosion from CMOS battery leakage
• Failure from some unknown component on the board which is not related to battery leakage and therefore not visible

Therefore, the only sure way to get a replacement power board, or to restore a faulty PCG-Fxxx machine is to remove the power board from a known-working machine. Unfortunately, without a solid diagnosis of the underlying issue, it is possible that other known working machines/power board may also fail in the future, irrespective of CMOS battery leakage.

Note: In addition, the laptop lid sensor board at the front of the power board can be damaged by battery leakage.

With the power board from the working PCG-F807K fitted into the PCG-F809K, the system works normally:

Despite fitting a known-good power control board, the restored Vaio PCG-F809K did not last long. After 2 days of use (installing the new hard drive, setting up drivers and getting Windows 98SE ready to install) the machine spontaneously shut down and it shows no signs of life any more:

• No standby indicator
• No battery charging indicator
• No response to power button

This is exactly the same behaviour observed when the PCG-F809K first arrived. I believe this to be an actual failure of the power control board in real time.

Unfortunately, at this point in time I have no other sources of alternative power control boards, nor do I think it is worth the risk of replacing it only to have it possibly fail again after a short period of use.

[Update - Jan 28th 2025] I tried powering both laptops and all three power boards with a bench PSU, with voltages from 12-20V DC. No change in behaviour; the laptop acts as if there is no power applied and there is no visible power draw from the bench PSU. Unless someone figures out what component(s) fail on these power boards, any Sony Vaio Fxxx series laptop is running on borrowed time until it fails.

Therefore, I cannot recommend any of the Sony Vaio PCG-Fxxx models for retro computing use, despite the really nice hardware specifications.