Two bits: backlit keyboard, power supply. New inspiron 17r SE

Hi guys, my dell inspiron 17r SE arrived yesterday and I am dead chuffed with it. I have two queries though.

1) I wasn't able to spec it with a backlit keyboard. From a search I have found that some Vostro keyboards (backlit) fits. Is £30 really the market rate for them? A lot more then i paid for my old studio 17 one. Are there any instructions on fitting them?

2) I have 2 x genuine dell 90w power supplies from my old studio 17. The new inspiron came with a 130w one. Through sheer excitement I found myself playing with my new laptop with it plugged into the 90w power supply. I wasnt gaming/anything big but the laptop seemed quite happy with it. Is there any danger of using the 90w power supply when I am in bed watching a film, then using the 130w when I am downstairs playing games?

Cheers guys

Sent from my Galaxy Nexus using Tapatalk 2

 

1. i ordered a Vostro 3750 backlit keyboard (RYYJ1) from Dell sweden....cost about £55 same as 7720. (you can also order the RYYJ1 BUT to your language...you have to call DELL and ask for the partnumber)

2.its just ONE rule when it comes to use power adapters............ the VOLTAGE ! it doesnt matter which current/watt the adapter is for, just look on the backside it says 19.5 V

(nearly) every single DELL 15" or 17" laptops using 19.5 Volt....i have 4 different Dell laptops...all of them use 19.5V.


so yes...it fine. you can use pa-10 (90W)...or pa-12 (slim 90W)...or pa-13 (130W).............and son on.

 

Many thanks mate, just what I was after!

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I am not typically one to contradict others but... As an electrical engineering student that advice should be taken with a grain of salt.
130 watts @ 19.5 volts = 6.67 amps of current
90 watts @ 19.5 volts = ~4.61 amps of current

The reason that this may be an issue is not a matter of damage to the laptop, rather that when you are using the laptop at full bore ie. gt650 on, 3.1 ghz, full brightness, harddrive running, cooling fans running, etc that the power draw on the laptop may be greater than 4.61 amps. At this point, your power supply will do it's best to keep up, probably to around 5 amps or a little bit more. Most power supplies are manufactured to a fairly tight tolerance, and will heat up if they are over drawn. This could lead to blown capacitors in it, potentially hosing the power supply. Your laptop may also have to supplement it's operating power with some of the battery's power. This could eventually shorten the lifespan of your battery. I don't see it as a big risk, however, I would not do it in practice.

 

Both of the above posters are right in part. Using a 19.5V adapter won't damage the laptop, but that assumes that you don't go trying to game on the 90W one. As long as you're just watching movies or whatever then you'll be fine. If you try and go over that however, the PSU will (as afbc0m pointed out) try and keep up, regardless of the impact to its components.

Think dog eating too much; it might throw up all over your laptop.