Dell inspiron 531s power issue *I hate these!*

[papuchazo]

So this is probably the 5th time this year I've had to deal with a dell inspiron 531s with power issue. I even posted a weird case a few months back here. This one is also kind of weird.

I was called out for a virus removal, turned it on at the customer's home and it turned on no problem. Logged into windows and saw it was indeed infected. Took it with me, performed a dust clean up with my trusty datavac and plugged everything in. BAM! No power, no lights, no fan spinning or even attempting to, nada, zilch.

After inspecting every single connection and just plugging motherboard and cpu still nothing. Whipped out my handy extra power supply for testing and the computer started right up no issues. Performed the full virus removal and tune up and connected the original PSU back and still nothing. Used a COOLMAX PSU tester, plugged in atx power and cpu and it did turn on the psu/hard drive/CD with all the proper readings for the volts. The only thing I notice kinda low is the PG = 250ms (My own testing PSU has 380 ms).

So couple of questions:
1. Could the dust clean up have caused this?
2. Is the PG indeed too low?
3. How come I can turn on the psu with the tester and everything seems to be getting power but when connected to the motherboard it refused to send the ON signal?

 

[NYJimbo]

The original PSU has some kind of power issue and its possible the coolmax tester completed a lack of ground issue or some other signal. Could be something else but I dont think the coolmax would be sending voltage to the other wires.

How many cables and which ones must be plugged into the coolmax to get it to start ?

Right now without knowing more I would say either moving the cables around for the dusting upset something that was borderline fail or the PSU died in your shop, which does happen. Whats dead exactly only you can tell with probing.

 

[nlinecomputers]

Power testers are of limited use because they cannot provide a load against the Power Supply. Without a proper load it is possible to provide correct voltage but not correct current levels. Thus your PSU tests good but fails to power up the PC. http://www.ehow.com/how_7713821_make-computer-power-supply-voltages.html

 

[papuchazo]

The original PSU has some kind of power issue and its possible the coolmax tester completed a lack of ground issue or some other signal. Could be something else but I dont think the coolmax would be sending voltage to the other wires.

How many cables and which ones must be plugged into the coolmax to get it to start ?

Right now without knowing more I would say either moving the cables around for the dusting upset something that was borderline fail or the PSU died in your shop, which does happen. Whats dead exactly only you can tell with probing.

The coolmax turns on the PSU with just the ATX power and CPU cables with no problem. I then plugged the other PSU sata power cables to the CD drive and hard drive and turns on just fine also.

Power testers are of limited use because they cannot provide a load against the Power Supply. Without a proper load it is possible to provide correct voltage but not correct current levels. Thus your PSU tests good but fails to power up the PC. http://www.ehow.com/how_7713821_make-computer-power-supply-voltages.html

As I wrote above I connected the other peripherals to provide more load against the PSU and it fires up fine with the tester. Maybe not enough. I'm more interested in knowing if the motherboard refuses to send "turn on" signal to the PSU if it feels the PG reading is too low.

I think I'll just eat the price of the power supply and replace it with a new one. I already ordered it just in case and should receive it tomorrow. I'll call the client and let them know what happened and that because of the extreme coincidental issue I'll provide them with a free replacement as a token of appreciation for being a long term client.

Thanks for the input as usual fellas!

 

[nlinecomputers]

As I wrote above I connected the other peripherals to provide more load against the PSU and it fires up fine with the tester.

But there is nothing to provide load against the motherboard connector. On most PSU's that is a different rail then the peripherals. Also if you are getting a variable signal on one line your tester isn't going to show that. A good analog voltmeter will show you that. You can see the needle jump. Good fast response DVMs can also show you but most PSU testers aren't designed to react that fast.

I've seen plenty of bad power supplies that test good using a Power Supply tester. That is normal.

 

[papuchazo]

But there is nothing to provide load against the motherboard connector. On most PSU's that is a different rail then the peripherals. Also if you are getting a variable signal on one line your tester isn't going to show that. A good analog voltmeter will show you that. You can see the needle jump. Good fast response DVMs can also show you but most PSU testers aren't designed to react that fast.

I've seen plenty of bad power supplies that test good using a Power Supply tester. That is normal.

Ok, thanks for the extra info.