Hello I'm trying to repair a HP V2110US laptop. I've downloaded the manual from HP , but only covers the disassembly. I need a schematic to trouble shoot the mother board. I don't have much experience with computers but can't afford the $$$$ they want for a new mother board. The problem is it does not power on. I've performed the checks I got from HP & looked for something obvious. Any help would be greatly appreciated. Thanks. ron
What experience of fault-finding electronic circuits and what test equipment do you have?
If "none" and "none" - then there isn't a lot that you can do except make sure all the connectors are connecting and that any component in a socket is very firmly in its socket. A schematic won't be a lot of help.
Working up from that, with a bit of experience and a multimeter, you can check the voltages being produced by the power supply. You may need to read the labels off the chips and look out their data sheets - that will tell you which pins are used and what voltages to expect. However, with power on, the slightest slip of a meter probe can short a couple of pins together and do a lot of damage to the electronics... Again, a schematic isn't really necessary.
Hopefully it is just a power supply problem - although complicated enough, it is one of the simplest bit of a computer. These are often discrete units and not built into the mobo - so may not be that expensive to replace. Again, a schematic of it is not that essential - there is often only a couple of key components and they will often have data sheets and application notes.
Working on further from that, you need a logic probe and to start looking for clocks and reset signals - which can be used to identify something as "trivial" as a clock generator going faulty.
Then you start entering the World of in-circuit emulators, logic state analysers and the like. But, if you know how to use that lot, your time is probably much too valuable to be spent fault-finding on a laptop...
I worked on a Compaq laptop that wouldn't power up. It turned out to be the input jack for the power supply was basically ripped off the motherboard because they had to "jiggle the cord to make it come on". What I did was solder a wire from the + of the jack to the + of the motherboard and a wire from the - of the jack to the - of the motherboard with justenough length on each so that hopefully if they "jiggled" it it would offer enough strain relief so the solder joint wouldn't break again.