power  button problem on hp g70 - Page 1
Forum section: electronics / general

author: plmmlp
author_rank: Newbie
timestamp: May 15, 2013, 04:02:37 pm
content: Hi while changing a screen on hp g70 laptop i ripped the ribbon on the power button i replaced the unit(eBay) won't power so reseated new unit several times so then had to teardown whole thing have now noticed 2 small leads with what looks like some sort of fuse/connection in a small plastic enclosure they are connected to 2 diffirent connectors 1 with the usb ports the other with the ariel that goes up thro the screen both open circuit. It still could be faulty PB unit wondering what these are and is there anything else could be the problem. The battery is powering fine but nothing when press power button

author: G7PSK
author_rank: Super Contributor
timestamp: May 15, 2013, 05:40:25 pm
content: Will the laptop turn on if you push the tac button directly with the plastic trim removed. On several occasions I have had the same trouble with the power buttons on laptops, what happens is the rubber top of the button itself gets worn down and then the plastic peg on the underside of the power switch no longer makes correct contact.

author: plmmlp
author_rank: Newbie
timestamp: May 16, 2013, 11:36:23 am
content: I took the cover of and pressed with a pencil just to make sure then took out MB checked it over no sign of anything beginning to think the new PB may not be good maybe the ribbon connection not right got it eBay Hong Kong is there any internal fuses as the original PB ribbon broke off is it usual to maybe cause a short back on the MB tried to get PB in UK but couldn't find supplier.Thanks

author: G7PSK
author_rank: Super Contributor
timestamp: May 19, 2013, 05:00:21 pm
content: Check the button with a test meter. Also go back over all the connections for the new screen ans also make sure that no connectors have been overlooked I have known laptops refuse to turn on due to a usb short or even thew usb sockets not plugged in. Was the computer working before the screen was replaced and is the hard drive starting up and have you tried an external monitor on the computer.

author: plmmlp
author_rank: Newbie
timestamp: May 21, 2013, 05:06:49 pm
content: Yes done all this I have voltage 3v at the power button but need schematic or what I should be getting on the ribbon connections which I have been unable to get thanks

author: G7PSK
author_rank: Super Contributor
timestamp: May 21, 2013, 09:07:01 pm
content: But does the button contacts close when the button is pressed, use continuity to check that. Just beacause there is power to a switch does not always mean that the switch itself is working.

author: Zapro
author_rank: Contributor
timestamp: May 22, 2013, 06:40:47 pm
content: If you want help fixing this, take some good sharp pictures of the parts in question. It is very had helping without having seen what it's all about.// Per.

author: plmmlp
author_rank: Newbie
timestamp: May 28, 2013, 11:05:57 am
content: Thanks lads i know it helps to get a visual i have stripped it totaly apart tested the MB as much as i could not easy everything is getting smaller put back together and discovered there's no negative on the new PB there is a neg at the MB so it must be the PB thought seeing as new it couldn't be it but since then i have discovered a lot of returns on parts from the east and its getting more expensive too think thatl be my last order without a good reference.

author: amyk
author_rank: Super Contributor
timestamp: May 29, 2013, 12:18:26 pm
content: Quote from: plmmlp on May 21, 2013, 05:06:49 pmAccording to the Internet this model's OEM name is Wistron Warrior Intel UMA - search for that name and you'll find the schematic. Didn't bother to look carefully for the power button but it should be around the keyboard/embedded controller area.