Help for HP Omnibook 430 notebook

Hi everyone, good morning!

I have got an HP Omnibook 430 notebook, is a really nice machine with a B&W passive screen and a really curious mouse. We can found a bit of information here http://www.hpmuseum.net/display_item.php?hw=228.

I will try to repair it, it seems that will be a big challenge. The old capacitors have been removed from the power supply section of their mainboard, and I don’t have any idea about their values or polarity.

Does anyone have a photo of the mainboard or the values of these capacitors?

Another possible problem is that I have seen three capacitors that look like cell batteries but with a weird voltage and capacity. They have a little label that says ‘5.5v 0.22F’, it the first time that I see one of them.

Any info or recommendation is welcome. I have already download the service manual, but it doesn’t have information about the electronics of the computer.

Thanks in advance!

Can’t help directly - worth asking around, at hpmuseum, maybe at vcfed forums. I think capacitors in power supplies probably aren’t too critical as to value, so if you see any vaguely comparable circuits you could use values from there. I believe it’s correct to use voltage ratings significantly higher than the voltage the capacitor will normally see, so a 5.5V rating is a bit of a surprise. But maybe this is normal. I do know that tantalums can fail short-circuit. Can you post a photo of these three special small ones?

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Hi Ed!
Yes, I couldn’t publish the post with a picture because I didn’t have the mainboard at hand to take a picture. This is the weird capacitor:

and a picture of the mainboard:

Those 3 then might be something like
EECS0HD224V - Supercapacitor, EDLC, 0.22 F, 5.5 V, Radial Leaded, SD Series, +80%, -20%, 5 mm
(but maybe you want them with “tabbed leads”)

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Thanks! Yes, it seems that it’s the same component, I will need to wait for the end of the quarantine here (I’m from Argentina) to get their replacements. I could try with normal 220uF capacitors, I would like to know if something else needs to be replaced.
I have found a video that shows some frames with the mainboard, but I can’t see the values of big capacitors (that are absent from my board) https://www.youtube.com/watch?v=NMTkyObiYeI

As I mentioned before, this seems to be a big challenge :smiley:

Beware: I think 220uF might be a thousand times too small!

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oh yes, I should use 220000uF capacitors :scream:

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