Can not find a user manual for lenovo computer

Give these two links a try ;
https://www.argos-support.co.uk/uploads/5497797_D0011.pdf

http://www.phonearena.com/phones/Lenovo-YOGA-Tab-3-8-inch_id9598/manual

Good luck

You can download a copy from here:
https://www.manualguru.com/lenovo/tab-a10-70/users-manual

Hi,

I do google your problem and look to the lenovo G500 manual.
here's the manual says.

sources: http://www.lenovo.com/shop/americas/content/user_guides/g410_g510_ug_en.pdf

BIOS password problems I forgot my password. • If you forget your user password, you must ask the system administrator to reset your user password. • If you forget your HDD password, a Lenovo authorized servicer cannot reset your password or recover data from the hard disk. You must take your computer to a Lenovo authorized servicer or a marketing representative to have the hard disk drive replaced. Proof of purchase is required, and a fee will be charged for parts and service. • If you forget your administrator password, a Lenovo authorized servicer cannot reset your password. You must take your computer to a Lenovo authorized servicer or a marketing representative to have the system board replaced. Proof of purchase is required, and a fee will be charged for parts and service.


But in my own way of troubleshooting.
1. open your Lenovo G500
2. Check your motherboard and look for bios/cmos battery.
3. Remove the battery
4. Get flat screw driver then put it between two pins where the cmos battery attached.
5. Hold it for 10 to 15 sec.
6. Put the cmos battery back and the motherboard
7. Power it up and holla the bios setting has been reset to default.

Here the sample image of Lenovo G500 motherboard


http://www.lenovo.com/shop/americas/content/user_guides/g410_g510_ug_en.pdf

Users Manual:
http://download.lenovo.com/UserFiles/UserGuide/en/User%27s%20guides%20and%20manuals/G460-G560/G460&G560%20UserGuide%20V1.0%20EN%20147002899-1.1%20%2810.03.18%29_web.pdf

Maintenance manual:
http://download.lenovo.com/UserFiles/UserGuide/en/User%27s%20guides%20and%20manuals/G460-G560/Lenovo%20G560%20Hardware%20Maintenance%20Manual%20V2.0.pdf

You can check the link below:

http://support.lenovo.com/en_US/guides-and-manuals/default.page?

Welcome to Fixya

Please click here for your laptop's user guide.

Thank you for using FIxya!

For T420 model Lenovo doesn't call it "User Manual" instead calls it "Hardware Maintenance Manual".
Here's a link to that manual:
http://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/0a60007.pdf

Hi,

For service manual : CLICK ME

For user guide : CLICK ME

in PDF format.

Hi There and Welcome to Fixya!

Optical drive in your Lenovo Y510 is not a customer replaceable unit (CRU), so I would strongly recommend for you to contact their helpdesk. The link to their consumer support can be found below :

Lenovo Helpdesk

Also, I have included the site where you can view (and download) the user's manual specifically for this computer. It does not have anything regarding dis-assembly but I'm quite sure it will be of a help :

Y510 User's guide

Good day and Thank you for using FixYa.

This is the page where Lenovo lists the various user manuals -- there are several but no specific "User Manual".
A "Get Adobe Reader" (free) button appears on the pages with the manual downloads (one click from the link below) download and install it if you need it.

http://www-307.ibm.com/pc/support/site.wss/product.do?subcategoryind=0&familyind=303747&brandind=10&doccategoryind=0&modelind=0&doctypeind=8&validate=true&partnumberind=0&sitestyle=lenovo&template=%2Fproductpage%2Flandingpages%2FproductPageLandingPage.vm&operatingsystemind=49979&machineind=303753

I hope these help.