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Laptop power supply.

Community Veteran
Posts: 1,236
Registered: 02-08-2007

Laptop power supply.

I was recently called to a house by a lady who's laptop was not powering up. Upon testing with a multimeter I confirmed that the power supply was dead. The laptop is a compaq presario C700.
I found the compatible supply on laptop-power.co.uk so ordered it. The original supply was 18.5V but the supply they have sent is 19V despite being listed at 18.5V on the website and the order. The current output is the same.
Will the extra 0.5V do the laptop any harm? I know Dell laptops can be very strange this way but I am hoping this will be fine. I would rather be sure as I obviously don't want to be liable for a new laptop!
8 REPLIES
Community Veteran
Posts: 1,850
Registered: 11-08-2007

Re: Laptop power supply.

it's doubtful half a volt will make much difference, but the item is not as advertised.  you are entitled to return it for a full refund.  it may be worth getting in touch with them to find out if they have a power supply of the correct voltage they can make an exchange. 
Community Veteran
Posts: 4,869
Thanks: 126
Fixes: 24
Registered: 14-07-2009

Re: Laptop power supply.

I bought a new Dell laptop mains power adaptor from a specialist laptop repair company recently (£35).  The owner said that the generic ones were prone to go wrong and take the laptop with them!!!  I trust this company as they have given me good advice in the past. 
Community Veteran
Posts: 1,236
Registered: 02-08-2007

Re: Laptop power supply.

OK, I looked closer at the package and yes it is the item I ordered but as you correctly said it is not as advertised. It does state on the box that it is 19V and compatible with 18.5V.
From what I can see an actual .5V supply is difficult to find without paying three times the amount for the genuine part. And it seams that companies like the one I bought off are selling the 19V etc as compatible parts. Surely they couldn't be doing this if laptops were failing all over the country as a result? This has gave me more confidence that the part would be fine.
As for Dell supplies I am aware that they are a completely different ball game. And as for generic supplies failing, well the original part failed. I do not mean any offence Reed but I personally would never 100% trust anyone advising me againist a product that they don't supply no matter how much I liked the company.
So I am now in this position. Do I call with the lady tonight with the new part and get her laptop up and running and make her happy for a fraction of what PC World quoted her or do I gave her the bad news and make her wait longer and probably pay more based on a tiny doubt? Then obviously go through the hastle of sourcing another part and returning the one I have.
win7xp
Grafter
Posts: 124
Registered: 14-03-2010

Re: Laptop power supply.

Sean the general rule of thumb is that the amps must be correct but the voltage output has a toleranceof +/- 10%.
Community Veteran
Posts: 1,236
Registered: 02-08-2007

Re: Laptop power supply.

The cabable amp output doesn't need to be the same, it just needs to at least the same. The power supply can be capable of outputting 100 times as much. The device will only draw the current it needs.
As for the voltage you have just confirmed what I am after reading elsewhere which has made my mind up that the supply will be fine. Thank you.
I am very familiar with power supplies/voltage/current etc. I was just very weary about this because it is someone elses laptop.
win7xp
Grafter
Posts: 124
Registered: 14-03-2010

Re: Laptop power supply.

If you ever need any laptop parts or fixes there is an excellent guy I use in Co.Tyrone.
He has been fixing laptops for years and is excellent.
Community Veteran
Posts: 1,236
Registered: 02-08-2007

Re: Laptop power supply.

Thanks but I am in South East Down so the time and the petrol wouldn't exactly make it worthwhile  Grin
Community Veteran
Posts: 1,236
Registered: 02-08-2007

Re: Laptop power supply.

I called with the lady this evening. Power supply works a treat, everyone happy  Smiley