Computer won`t start up after replacing blown psu.

[richhornick]

I have a strange problem that I cannot figure out. I have an emachine W2785 which stopped powering up a couple weeks ago. I pulled out the power supply and noted that it was blown (the circuit board showed spots where something overheated). I purchased a new power supply (Rosewill RV350). This was an upgrade from the original which was only a 250 watt. Well, I placed in the the pc and everything powered up, except the keyboard and monitor. The keyboard lights do not come on, and the monitor comes on with the screen stating that monitor is ok, check pc (I hooked it up to my dell and it worked fine). So imediately I thought the motherboard was bad. I purchased a Biostar M7Vig400 from newegg and placed it in the pc. Started the pc up and the exact same thing happened - everthing worked - fans, cd drives, harddrive, except the keypboard and monitor. I tried disconnecting everything to see if I could diagnose what piece of hardware was causing the issue, but to no avail. I am very frustated and would appreciate any support anyone could offer. Here's the original specs for my computer - notate I changed the power supply and motherboard.

BOM for : W2785
Part Category
ODD1: DVD NEXGEN 16X 100127
Memory: MEM, DDR-RAM 512MB (Max. 2GB
HDD: HDD, 80GB 5400rpm
CHASSIS: CHASSIS, NEXGEN-2 MAIN CHASSIS FRAME
MB: MB, AM39L/1.0 462P
CPU Fan Type: Fan ,58*68.3*80mm
Speaker: SPEAKER, SP-30A (AMPLIFIED)
Power Supply: PS, 250 WATT
FDD Model: FDD, D353M3D
Video: Video, Integrated
Mouse: MOUSE, SILVER WHEEL
CPU: CPU, ATHLON XP 2700 462P 333FSB
Keyboard Model: KB, PREMIUM BLACK KB-0108,PS/2 PORT
ODD2: DVD-DUAL Nexgen2 (16x10x40x+4x2.4x12x)
LAN: LAN, 10/100 Integrated
Modem: MODEM, V.92 56K

Thanks for your time in advance.

Edit: Please use proper thread titles from now on. Thanks.

 

[Rik]

You need to explain exactly what you have replaced and list everything you are using from the original machine. Its possible that something else has blown in some way and is causing a drain on the 5v rail. There are many other possibilities but that one sounds the most likely.

 

[richhornick]

To date I replaced the power supply and motherboard. I only thing I added to the original system was an additional 512 mb of memory. Everything else is the same. Does that help?

 

[riekmaharg2]

try unplugging everything inside your comp apart from your motherboard,cpu, and power/reset button and see if you get a post screen. Then if the screen and keyboard work, then try plugging everything back in again 1 at a time testing your computer after each thing you plug in then you will find the problem. I would suggest putting the memory back in first if your monitor/keyboard works.

 

[richhornick]

Thanks for the suggestion. I tried doing what you suggested, but to no avail. I still get no lights on the keyboard, and the monitor states "self test, check your pc and signal cable, monitor is working". I also am getting no beeps when I turn it on. Can you think of anything else? Thanks again.