Some more photos.

Additional information about my repair here:

How to filter out very high frequencies with a circuit?
Re: Replacing the NiMH CMOS battery in my Toshiba laptop

Them tard batteries !!

My recently purchased PCG-F809K arrived, not powering on (as described), and it has corrosion around the same area:

Nothing seems *too* bad; nothing was falling apart, and it doesn't appear as if the (visible) corrosion has gotten any further than the battery terminal socket, or the ground plane of the lid sensor. I'm not entirely sure what I can see would stop it from powering on.

I'll clean up what I can see, test for continuity on the bits I can see were touched and re-assemble.

I've another one of these coming; a PCG-F807K, and that one at least is tested and powering on, so it will be possible to compare/swap internals if needed.

.... and nothing. I can't see any broken traces, and the corrosion is so slight that I just can't see how that alone would have damaged this power control board to the point of being broken.

I wonder if there is something similar to the Thinkpad T20/21/22 'blink of death' going on - where there's some power control IC on this sub-board that ultimately fails?

I can't see an ADP3421 power controllers (the suspected fault on dead Thinkpads) on the board (it's still in the case, but everything stripped off - I suppose it's possible there may be something on the underside).

There is an ADP3420 on the MMC-2 processor module, but I've not heard any horror stories about MMC-2 device... and if there was, then they'd be on every single P2/P3/Celeron laptop that ever used them.

I've got both the 'other' known-working PCG-807K on the way, but have also been able to track down a seperate power control board. I'll give both options a try.

Inspected the motherboard and confirmed that the main ceramic fuse (labelled 125V 5A) to the right of the power jack is fine, 19.5v DC is getting to the rest of the motherboard.

I can pick up 19.5V DC on an empty pad on the front sub-board, as highlighted in red, above. There are also some lower-voltage readings (between 0.6-2.0v) on several of the battery connector pins, so there is at least some voltage regulation/conversion going on by the power control sub-board, so it would appear the input voltage from the motherboard is at least going in to the sub-board.

It's so densely packed with bird-seed components and so fine (comparatively, next to the 286 and 386 stuff I've repaired) that I don't even know where to start trying to trace the power-on button. I think I'll have to wait for the spares to arrive.

I had one of these boards that I believe was somehow damaged due to corrosion but in a way that I couldn't detect. Swapping the whole board (the large one) fixed the problem for me.

There is also a small chip behind a removable door on the underside of the laptop. The laptop will not function without it. I don't recall if it powers on at all or if it's just a blanks screen when removed.

Just checked, it's there - I'm guessing it's the bios/firmware since it's a flash-device-shaped part?

These power boards seem to be common to a huge number of sub-models in the range (in fact the entire pcg-f* range appears more-or-less unchanged in terms of internal layout and major physical parts, from start (early P2) to end, except specification of cpu, sound and video)... so it should be feasible to source the power control boards from 'less desireable' donors if they can't be repaired... though that's not a long term solution. It would be really good to understand the problem and identify which part(s) require replacement.

I also believe that this part is similar or the same across this line. Swapping in a donor board is exactly how I fixed my issue. However, when sourcing parts, there is no way to know if the donor machine isn't corroded or damaged as well. And this laptop is too complicated for a seller to take apart to check.

I swapped in the power board from another PCG-F series (not the complete machine I have coming) and it hasn't worked.

Either the power board is faulty, like my original one, or there is something more at fault.

We should know for sure when the working laptop arrives.

Do you have a link to replacement batteries ?
I have a few of these Vaio laptops.

Nope. Not found any. There are a few electronics resellers in China that claim to have them, but no stock that I have seen.

Closest I saw was an industrial company on Alibaba that purported to sell reproductions of them, but minimum order sizes of 10. It's not worth it when it is going to cost the same as *both* laptops!

That was for the pcga-bl71 type.

Internally they appear to be standard cells, btw. At least one forums post I found seemed to indicate that it was feasible to replace the cells and do something with the internal battery controller IC to make them think they were new again.

I have a different problem with this series of laptop that I would like to try and confirm with someone. When I turn mine on, there is a high pitched noise that comes out of the laptop. It's extremely high pitched so you might not hear it if you can't detect this frequency. I tracked it down to the little circuit board that connects to the LCD. It stops making this sound after about a minute or so after powering on.

I thought that maybe this board was defective, so I replaced it with one from a donor laptop but it does the same thing.

Has anyone experienced this before? Try turning your laptop on and hold your what above where the speaker area is and see if you can hear it.

Kahenraz wrote on 2025-01-13, 19:38:

I have a different problem with this series of laptop that I would like to try and confirm with someone. When I turn mine on, there is a high pitched noise that comes out of the laptop. It's extremely high pitched so you might not hear it if you can't detect this frequency. I tracked it down to the little circuit board that connects to the LCD. It stops making this sound after about a minute or so after powering on.

I thought that maybe this board was defective, so I replaced it with one from a donor laptop but it does the same thing.

Has anyone experienced this before? Try turning your laptop on an hold your what above where the speaker area is and see if you can hear it.

Happy to do so if I can get one to work! Latest shipping news shows the other PCG-F807K a couple of days away.

The PCG-F807K (P3-650, 1024x768) arrived this morning, and as listed it is indeed working.

Filthy, and scratched. With a backlight that has seen better days (pink tinged screen). But working:

It didn't take long to remove the power sub-board and temporarily fit it into the PCG-809K (P3-850, 1400x1050):

It works. So it is clearly another example of a dead power sub-board (one working board out of 3 that I now own). This one also has some slight corrosion to it, approx the same as the last 'spare' power board I acquired (limited to just the battery lead header pins). I don't think the corrosion has anything to do with the failure of these parts, at least, not in examples like the last two, where the corrosion is very, very minor.

I'm convinced one of the IC's on these boards is failing due to age or use, and has nothing to do with the battery leakage. Which likely means that it's only a matter of time before they all start to fail.

At least now I have the best model PCG-F* (1400x1050 screen, fastest CPU) with sufficient parts (including battery cover) and several spares (2x FDD and 2x DVD) to put together a complete one. The original plastics on the 809K are also in pretty decent condition.

Spot the working one...

megatron-uk wrote on 2025-01-15, 12:51:

I'm convinced one of the IC's on these boards is failing due to age or use, and has nothing to do with the battery leakage. Which likely means that it's only a matter of time before they all start to fail.

Thanks for updating, that means I don't have to disassemble my PCG-F480 to prevent leakage.

MAZter wrote on 2025-01-15, 13:09:

megatron-uk wrote on 2025-01-15, 12:51:

I'm convinced one of the IC's on these boards is failing due to age or use, and has nothing to do with the battery leakage. Which likely means that it's only a matter of time before they all start to fail.

Thanks for updating, that means I don't have to disassemble my PCG-F480 to prevent leakage.

Oh, the battery does leak! Every single one I've had in my hands has shown some level of leakage... I'm just not convinced that the battery leakage has anything to do with the failure of the power boards. Perhaps in situations like that of the OP, where part of the pcb has literally been eaten away, but in cases like mine, where it is no further than the battery header pins? I just can't see how that would cause these to fail.