Getting no monitor signal, no keyboard or mouse indicator

[kdkhan]

I recently build a PC at my own very first time. Surprisingly, it was 100% Ok and I used it for around a month. Later I sold my PSU and RAM to a guy as I have an other branded PC for my own use. Now I again bought used RAM of same specs i.e. DDR2 800MHz and a PSU of Coolermaster 650 watts and installed them in. However, there comes no signal on my monitor even standby orange light doesn't go green for a second. Similarly there is no power / light on my keyboard and mouse while CPU fan and two other case fans are spinning and CPU led is flashing properly. There is no beep sound whatsoever until I remove the RAM. The tower looks working but no output.

I checked my monitor, hard drive, graphic card and RAM on other system and they all are working fine. I arranged an other PSU of 450 watt but no success. Even I replaced my CPU but in vain. While motherboard supplying power to all fans, its system light on board is flashing, and when I remove the RAM it properly gives the beep of no RAM but still nothing on monitor, keyboard and mouse. I tried different dimms but no luck.

System consists of following components:

1. Motherboard Asus P5QL Pro
2. CPU C2D E7500
3. RAM Kingston 2GB
4. PSU Coolermaster 650 and Absolute 450 watt
5. Hard Disk Seagate 500gb
6. Graphic Card MSI NX7900 256 MB
7. Casing ATX CoolerMaster

I think my mobo is OK as all fans are spinning, board and led lights are fine and it beeps when there is no RAM.

Please help me out as variety of options I so far applied could bring no fruitful result.

 

[Lokalaskurar]

Let's see now, I think I might be able to give you a qualified guess as for your PC's problem:

1. There comes no signal on my monitor even standby orange light doesn't go green for a second.

2. Similarly there is no power / light on my keyboard and mouse while CPU fan and two other case fans are spinning and CPU led is flashing properly.

3. There is no beep sound whatsoever until I remove the RAM. The tower looks working but no output.

This basically would indicate that unless the PSU delivers inaccurate voltage, your motherboard is zapped by electrostatic discharge. Shorted, in other words. Personally, I've seen the very same symptoms on dozens of customer-PC's, and it's always the motherboard.

I recently build a PC at my own very first time. Surprisingly, it was 100% Ok and I used it for around a month.

Glad to hear that it worked your first time , but tell me this; did you (do you?) use the proper protection? Any of the following?; ESD-wristband, ESD-mat, PSU-cord plugged in grounded outlet, plastic gloves(/plastic screwdriver)?

You mentioned that you did build it for the very first time, so I did figure that you might be in the crosshair of classical beginner-mistakes (forgive me if I'm incorrect, I'm not trying to be rude or anything )

ESD is a very serious thing, and it costs the industry millions every year. When building PC's, it's very important to be grounded, or else you might zap components. Some damaged components might not even show any symptoms until after a very long time.

Later I sold my PSU and RAM to a guy as I have an other branded PC for my own use. Now I again bought used RAM of same specs i.e. DDR2 800MHz and a PSU of Coolermaster 650 watts and installed them in.

Let's see now, you opened the case up again, installed the components, and now your PC is displaying classical shortage symptoms?

I checked my monitor, hard drive, graphic card and RAM on other system and they all are working fine. I arranged an other PSU of 450 watt but no success. Even I replaced my CPU but in vain. While motherboard supplying power to all fans, its system light on board is flashing, and when I remove the RAM it properly gives the beep of no RAM but still nothing on monitor, keyboard and mouse. I tried different dimms but no luck.

You've tested every other component, and the PSU seems strong enough to support your setup, and your PC is displaying classical shortage symptoms.

Yeah... sorry to say this, but I think you've shorted your motherboard.

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I think my mobo is OK as all fans are spinning, board and led lights are fine and it beeps when there is no RAM.

It usually still does that after a shortage...


I'm going to let some other TechSpot hero say his/her thoughts about this, but at least, I think your motherboard is shorted due to ESD from your latest component-swapping inside the case.

Provided of course that you did not use the proper protection against ESD...


Zapping modern MB's is much easier too, as the circuits are getting smaller and smaller = easier to break with discharged electricity.