laptop fail - Page 1
Forum section: electronics / beginners

author: christos
author_rank: Regular Contributor
timestamp: June 03, 2014, 10:22:00 pm
content: hello.. my brothers laptop had a problem with the power jack..so i took it apart and fixed it..but my brother saw for the first time a motherboard and took a wire and played with it on the MB ..he told me he saw sparks and then the laptop didnt start...heres a photo where he saw the sparks..http://postimg.org/image/tb3s8j4c7/what can i do?

author: 128er
author_rank: Regular Contributor
timestamp: June 03, 2014, 11:17:06 pm
content: Hmm, at first glance it looks like that he shorted a power rail as he bypassed the capacitor with the wire. Look for surface mount fuses near the power input, labled as "F". There i would start. The model of the laptop and a good photo of the motherboard would be useful.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: June 03, 2014, 11:19:09 pm
content: What I would do.Take anti static precautions.Remove battery.Check across caps and silicon in the area for short circuits.Reverse engineer a schematic of the effected area.Try to understand how it is meant to work.Turn it on and see if anything is over heating.if you can spot what is not working, but checking voltages against expected voltages.Especially check the incoming psu voltage, often 19V.Give up and put it in a cardboard box so you can throw it out next year.Oh forgot to mention, it sounds like a bit of sibling discipline would not go astray.

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: June 04, 2014, 12:39:28 am
content: With any luck it will just be the cap that needs replacing.What make/model is the laptop ,do you have a schematic ?

author: SeanB
author_rank: Super Contributor
timestamp: June 04, 2014, 03:20:23 am
content: Buy new laptop, with your brother paying for it.

author: nanofrog
author_rank: Super Contributor
timestamp: June 04, 2014, 07:19:48 am
content: Quote from: SeanB on June 04, 2014, 03:20:23 am+1And if by some miracle the OP can get the old one fixed, do so and sell it off. Keep the money.If the brother complains, tell him the cost of the new laptop is a "Stupid Tax", and the money made on the old one is for diagnostic & repair fees. He might get pissed, but I bet he won't do it again.

author: Psi
author_rank: Super Contributor
timestamp: June 04, 2014, 08:12:12 am
content: See if you can find any SMT fuses around the board and check if they are open.That would be my first thing to check.They will probably be located around the powersupply area (section with all the inductors and big diodes).Google image search "SMT fuse" to see what the can look like

author: lowimpedance
author_rank: Super Contributor
timestamp: June 04, 2014, 11:51:50 pm
content: Quote from: christos on June 03, 2014, 10:22:00 pmWell..........A few well chosen 'words' to your brother, then toss the now dead one out and tell him to buy a new one.Oh and keep loose wires and sharp objects away from him.

author: retrolefty
author_rank: Super Contributor
timestamp: June 05, 2014, 01:22:21 am
content: Just keep in mind that the day my come when your brother bails you out of jail or some other jam.

author: Rigby
author_rank: Super Contributor
timestamp: June 05, 2014, 02:20:55 am
content: A) remove the battery and power when you work on a laptop...B) explain to your brother that by breaking the laptop, he has both learned a lesson and paid the tuition for the new knowledge.

author: Rick Law
author_rank: Super Contributor
timestamp: June 05, 2014, 05:36:26 am
content: You probably already know, but just in case.If you want to take some trouble (and takes longer) but make more, test and sell the parts. LCD screen alone may bring in USD $50-$100 (no dead pixels). The inverter board is about $10.The CPU fan/heat sink is another frequently fail part, but it may be best sold with the motherboard.The RC crowd would likely want the battery pack to strip. For a fairly new laptop (battery), it should worth about $3-5 per cell so a 6 cell battery may get $20+. Make sure you don't open the pack so the buyer knows the cells were original cells.Combine all the screws and sell the screws as a pack - "entire screw set for Dell (or whatever) model XXXX".Good luck.

author: amyk
author_rank: Super Contributor
timestamp: June 05, 2014, 12:23:09 pm
content: Find the schematic, trace the power path. Get your brother to help too.

author: flolic
author_rank: Frequent Contributor
timestamp: June 05, 2014, 12:45:14 pm
content: If he just shorted and killed one of supplies, then there is some chance for repair. Can be blown mosfet of power controller chip.If he connected one end of wire to the positive pole of supply (+5v, +12V or +~18V depending of laptop) and dragged it across the board, than I'm sorry...