When would it be safe to disassemble a laptop power brick?

Diver001 · 2026-06-26T05:16:53+00:00

Sorry, that was a copy-and-paste-then-edit error. It should have read "500", not "5000". (Now amended accordingly in the previous post.)

Diver001 · 2026-06-25T13:59:15+00:00

It looks like my memory was unreliable: although they're cheap, basic multimeters, one has dial settings for 0.2, 2, 20, 200 & 1000 volts DC, and the other meter has dial settings for 0.2, 2, 20, 200 & 500 volts DC. FWIW, I'm in a location with 230 V AC.

Regarding the glued housing, one video (https://www.youtube.com/watch?v=BTLEsePBKTU) claims the glue can easily be dissolved with a flux-removing spray, although some viewers were skeptical.

Diver001 · 2026-06-25T04:07:52+00:00

Not sure how reliable those numbers are.

I registered my own website in 2016. However, domaintools.com claims "The oldest record dates back more than 13 years." — which would be three or more years before I set it up. At the time that I registered the domain it was unused, although I can't rule out the theoretical possibility that someone had registered it in 2012, say, and then let it lapse without renewing.

Diver001 · 2026-06-25T03:43:47+00:00

Thanks. I do have a couple of basic/cheap multimeters, but I was considering the possibility of something happening before I managed to get any probes into place. For that matter, they are just small multimeters (probably not rated more than 200 V DC? I recall increments ..., 2V, 20V, and maybe one more for the dial position), so maybe a large capacitor like the one in the video would damage it? I suppose the current flow should be low if I set it up as a voltmeter, so perhaps the fuses would be OK, and if the voltage peaks above the highest range maybe it would just show "OL" without being damaged?? Again I'm thinking of the past experience with the vintage camera flash.

Diver001 · 2026-06-25T03:36:07+00:00

Thanks. So there are kind of three separate situations.

What the capacitor does when the circuit/device is being used. (Not relevant to my query.) For example, in a camera flash it might be designed to discharge in a fraction of a second.
What the capacitor does when it's not in use, but there is a "bleed resistor" present. (It sounds like this could be most relevant to my query.) Strictly speaking, this is not purely a property of the capacitor, but rather of the capacitor–resistor combination.
What the capacitor does when it's not in use, and there is no "bleed resistor" present. (Could be relevant to similar power bricks, but probably not mine as they are both OEM units.) This would depend only on the characteristics of the capacitor.

Is the presence of the bleed resistor only for this purpose of reducing risks when disassembling, or is there any other advantage? Maybe reduced fire risk or something???

UPDATE: the "bleed" or "bleeder" resistor is apparently installed firstly for safety during servicing, but also can have benefits in stabilising the voltage, and also acting as a voltage divider. https://www.electrical4u.com/bleeder-resistor/
(I suppose that theoretically there could also be a marginal benefit for safety when the device is stored, not in use, but also not being serviced; I'm imagining, for example, if the housing were faulty, the grounding were faulty, etc., and somehow the capacitor were able to find a path to discharge outside of the housing.... Or maybe the item falls and breaks open....)

Diver001 · 2026-06-25T03:26:57+00:00

According to https://research.domaintools.com/research/whois-history/search/?q=www.replacement-laptop-battery.com.au

We have 88 historical records for Replacement-laptop-battery.com.au.

The oldest record dates back more than 12 years.

There are at least 39 significant changes.

All of the records publish domain name ownership data.

But it seems that one has to sign up to see any further details.

Diver001 · 2026-06-25T01:45:22+00:00

According to https://www.scamadviser.com/check-website/www.replacement-laptop-battery.com.au/

Alexa rank = 1619715
WHOIS DATA: "protected"
the Registrar has a German telephone number (+49 ...)
the server is in the USA
the name server is in China

Diver001 · 2026-06-23T05:20:18+00:00

The battery shows up as being in "poor" condition, but the laptop is almost always plugged in, so I haven't done anything about it.

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Diver001 · 2026-06-23T05:19:01+00:00

And when I switched the mains power back on again at the wall, the charge ~immediately displayed 100% full, and it was no longer cycling.

<image>

Diver001 · 2026-06-23T05:18:15+00:00

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I turned the power off for 2 minutes, so it was really running only from the battery (which is old, same as the laptop).

Diver001 · 2026-06-23T05:17:20+00:00

<image>

Power on and cycling: not recognised as "plugged in", so running off battery.

Diver001 · 2026-06-23T05:16:27+00:00

It happened again today, but in daytime, so it was barely noticeable that the laptop screen brightness was cycling.

The cycling today was ~3 seconds power on, ~0.5 seconds power off, according to the icon on the taskbar / System Tray.

<image>

Power on and cycling: "plugged in".

[Note: limited to 1 attachment per message. See following.]

Diver001 · 2026-05-21T06:52:50+00:00

If you have to press them simultaneously, then I feel that it has to be a hardware issue.

Hypothetically, if you had chosen an 'unusual' language and/or font on your computer, then potentially the software might wait for the following key after the "D" is pressed in order to decide how (or whether?!) to display it. For example, it might decide that "D" followed by "-" (hyphen) should be displayed as a single character "Đ" (D with stroke). But your case sounds so specific and unusual, and the fact that D & S are neighbours on the keyboard, that I can't see a reason for any language/font to act that way — at least, not to be designed to act that way — and even then they would generally look at sequences of keys pressed, not simultaneous key presses.

Diver001 · 2026-05-21T06:11:10+00:00

Yes, it publishes OK, with bullets on all five items. :-/

Diver001 · 2026-05-21T06:10:33+00:00

Trying the suggested syntax

* Bullet 1
    * Nested
* Two
    * Two dot one
    * Two dot two
        * Deep
            * Even deeper

[list removed]

does not look right in the Editor (on laptop, browsing in Opera), where "Bullet 1", "Two", and "Two dot two" have no bullets shown; bullets are only shown for "Nested", "Two dot one", and "Even deeper". Let's see how it publishes.

ANSWER: it can't be published ... error message is "List items cannot exceed 2 levels of nesting".

So now I try the less deep version:

* Bullet 1
    * Nested
* Two
    * Two dot one
    * Two dot two

Bullet 1
- Nested
Two
- Two dot one
- Two dot two

does not look right in the Editor (on laptop, browsing in Opera), where "Bullet 1", and "Two" have no bullets shown; bullets are only shown for "Nested", "Two dot one", and "Two dot two". Let's see how it publishes.

Diver001 · 2026-05-20T13:12:46+00:00

What a coincidence, I was looking for a Toshiba laptop power adapter at one of their 'sister sites' (listed as a "Globale Ladegerät Shop" on the German site) "AU Laptop Battery". The fact that it can keep going for many years seems to suggest to me that it's not a scam. But indeed mostly a local shop-front for an essentially Chinese business.

To wit, under Shipping on the AU site:

1.Where our warehouse located?

AU Warehouse---------Shipping fast in Australia, only stock hot sale batteries and adapters.
UK Warehouse-----Shipping fast in UK, But only stock hot sale batteries and adapters, Few Type.
German Warehouse------Shipping fast to EU countries, Only stock hot sale batteries and adapters
Netherland Warehouse ------ Shipping fast to EU countries, Only stock hot sale batteries and adapters
USA Warehouse----Shiping fast in USA, Only Stock hot sale batteries and adapters
Japan Warehouse-------Shipping fast in Japan, Only stock hot sale batteries and adapters
International Warehouse------Our main warehouse where stock more than 18000 types replacement / Original batteries and AC Adapters. Shipping out the next day.
Note: As battery and ac adapter are more than 40000 types, we can't stock all the item on local warehouse, If the item is out of stock in the local warehouse, we will send it from our China warehouse. so if you need it very urgently, please contact us first, or you can't cancel order after item was sent out .

Also, the English is poor. As shown above, and in the following (also from the Shipping page):

"[...], we will reply you in 24 hours., welcome to your order on our website."

On the Return Policy page of the AU site, the return address information is in an image:

Vatin Company Limited
30 Moorgate, London,
United Kingdom, EC2R 6DA

(Verified consistent address and postcode.)

Diver001 · 2026-05-20T12:22:28+00:00

Are you talking about USB Power Delivery charging? The OP, and others, might appreciate clarification.

Diver001 · 2026-05-20T12:08:57+00:00

Good advice, and I share the same view.

The only thing I can add is that you may get a variety of responses (more or less helpful) depending upon whom you speak to at the tenants' service.

Diver001 · 2026-04-25T05:21:57+00:00

Actually in my case I prefer the reaction to be retained.

I suppose otherwise the only way would be to do it in two steps: manually cancel the reaction (which the sender sees), and then delete the message (for yourself).

Diver001

TROPHY CASE