Laptop PSU advice?


I bought a used PB laptop for

Quite a lot of laptops have completely different input DC voltages to the actual internal battery voltage.

You would need to investigate from the laptop manufacturer the specification of the external PSU etc to confirm whether it is the correct one for the laptop… If the Plug into the laptop is overheating then perhaps there is a poor connection or something else is amiss…Additionally Laptop P4’s were renowned for their Processor heat and likewise most laptops of that generation/type had comparatively short battery duration with high processor load…1 to 1.5 hrs was not uncommon…

Hi m8

Yeah i spose i best contact them, I did email a member on eBay, hada lot to do with
laptops ans stuff, his reply was:

Hi Simon

i think its not worth repairing your laptop



8O not quite what i was hoping for lol

It sounds in the ballpark, I’m using a Sony laptop, 14.8v/4000mah battery, with the original 19.5v/ 4.7 amp psu.

Cheers Niko, dont help much though, it means theres something else amiss :frowning:
mmm, fix it good and get it on eBay pmsl…

Older laptops were good if you got 1-1.5 hours on battery, I used several at work and always had them on mains power, none would last the 1hour 40 minute train journey home. Laptops are notoriously expensive to repair since about all you can change is the h/disc CD/DVD and floppy, modem card (if separate) memory and then its a m/board with cpu usually soldered on. Also cases were made to take the original manufacturers parts so spare came from only one source. I just persuaded my son to upgrade his desktop rather than get a very expensive laptop to play games on because if it went belly up after guarantee runs out usually all they are fit for is the bin unless its really simply. His S.O. just did not like the desktop sitting in the corner of the room!!!


Thanks for the info Stuart

It looks like it might be a spares of repairs then :frowning:
Shame, I spent

Its getting harder to solder the connector now as there is nothing
left on the bottom of the main board for the solder to stick to on
the live pin :frowning:

I am at a loss as to where to go from here, the plug only gets too hot
when i am using the lappy and its connected to the PSU, if the lappy
is off and recharging that its fine, it dont get too hot, Perhaps the lappy
is drawing too much power from the PSU when its powered on?

If its getting too hot that would indicate to me that the current is too high for the laptop, heat is generated by resistance so it may be worth looking for a power supply with the same voltage but lower amperage.

A main cause for excess heat at a plug and socket connection is poor contact spring rate in the chassis socket. If it has been over heated numerous times then that is another compounding issue as the contact spring metal may anneal and soften each time making less contact pressure. It is a major cause of house fires with a 2kW heater load on a weak wall socket…

I will see if i can get hold of another PSU, thanks Fairweather

Graeme, What do you suggest please?

Also what can i do about the solder no longer wanting to stick to the main board?

I dont want to bin it as its not too bad of a machine, 15" screen, P4 cpu and 1gb ram
if its ever working again then it would be deffo used for the dedicated server

You may want to run wires outside to a temporary/second plate to mount the socket onto and seek a replacement socket and mount that in a hole in this temporary second board. Obviously the plate will have to be a solid sort of plastic or type of circuit board. You would just have to take care when plugging in and out of the “loose” socket. that’s a possibility as there will not be any strength left where you are soldering too. You can lay a heavier bit of single wire over the circuit board line/track, and solder onto the end of that.

Are you using flux when you solder the connection?

Have you got a meter to measure the current? If you can measure the current and it’s ok, and if you just want to use this as a wx server, then I would forget the plug and socket just connect the psu directly.

Thanks Graeme, some good help there :slight_smile:

Hi Dan, The flux is built into the solder, although it aint the flux, theres just nothing
left on the board to solder to the pin to… It looks like i will have to go for the new
connector and try to lay a bit of wire over the pin like Graeme suggested and solder
over that and see how that goes, I have found the connector on eBay for about

Current is what I was meaning to measure

But then the question is, whats causing this to happen in the 1st place :?

Two choices as already suggested by others, either the current is too high, or the connector is bad and has high resistance and that’s causing it to get hot.

Ah, sorry, not sure how to measure the current, im ok with continuity and volts
but thats as much as i know on a multimeter :oops:

Then it could be a mixture of both i suppose, current to high thus melting the connector

This is my multimeter, possible to point out which setting i need to test the current please?
I dont even know why there is 2 connectors for the red lead lol #-o


From Wikipedia:

solder is a fusible metal alloy with a [color=red]melting point or melting range of 180 to 190

Put the switch to the 10A range (red arrow)
Put the Red lead in the 10A hole (red arrow)
Leave the black lead where it is

Put the meter in series with one side of the power supply lead to the laptop, not across it. If you don’t feel comfortable doing this, then don’t.



Thanks Niko…Its fluctuating big time between 0.37 and 3.45 i think it was its was going to quickly
it was like going up in steps also the black probe tried fusing to the outer lol