Nothing turns on, green light is lit on the motherboard. jumpered the ps-on at the connector and checked 12 and 5 volts from power supply. Jumped the switch and still nothing, thinking a problem on my motherboard

Fuse in the plug?
Sounds like a good design...........

[Since I do not know, is this an indication that the power cord's plug, on the surge protector side; has a fuse in it? ]

So what is the method to check a fuse?
Is it the preferred method to eyeball it?
No
A multimeter set to OHM's, should be used to check it. (1K)

"It looks like the fuse element is going across okay"
Not always true. May be present, but not actually be touching one of the ends, and fool you.

Going with the premise that you KNOW;
A) The fuse to be good
B) The power cord TO Power Supply is good.
C) THE receptacle in the surge protector, that you have the power cord plugged into; is good.

Reasoning on the last statement?
I have had Many surge protectors, where just THAT receptacle was bad.
"Hmmm, power LED light is on, so surge protector is on,
router has power, monitor has power, and so does the printer.
Let me plug a table lamp into THAT receptacle, the computer is plugged into........"

Nope! NADA!

Power is KNOWN to be getting TO Power Supply?

Okay. Suggest a simple test now.
This test determines if the problem is the Power Supply; Or the Power On switch.......

The test is to use a jumper wire, on the ATX main power cable's connector.

Do Not know which one the Medion has.
It is either a 20-pin ATX main power cable, or a 24-pin ATX main power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20

[NOTE* Color of connectors does NOT matter ]

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

Whichever one your Power Supply has, look for the GREEN wire.
The Green wire is the Soft Power On wire. (Abbreviated as PS_ON)

The Green wire is Temporarily jumped to ANY Black wire.
ALL Black wires are Ground wires.

The preferred jumper wire is a straightened out paperclip, bent into a U-shape.
Turn the U-shape over.
The top of the U is wrapped a few times with black plastic electrical tape. (Color doesn't matter. It's just that Black is more common)

This taped area is for your fingers, and thumb to hold onto.
The 'Legs' coming down, are what is used.

Power Supply plugged into power, and 20 or 24-pin ATX main power cable; plugged into motherboard.

The BACK of the ATX main power cable's connector, is where the wires go in.
It is the Back of the ATX main power cable's connector, where the U-shaped jumper wire is to be used.

One leg slides down into a socket hole, that has the Green wire in it.
Slides RIGHT NEXT TO the green insulation of the wire, and down into the socket hole.

MUST slide down into the socket hole far enough, that the U-shaped jumper wire touches a female metal terminal; that is on the end of the Green wire.

This is an example of what the female metal terminal connector, looks like,

http://www.mcmelectronics.com/product/28-9420&utm_medium=Affiliate&ref=cj&utm_campaign=CommissionJunction&utm_source=CommissionJunction?utm_expid=8634549-14

Looking back at the Playtool link, look at the middle photo.
There you see the ATX main power cable, unplugged from the motherboard, and you see a FRONT view of the connector.
Here you can make out the open end, of the metal terminal connectors mentioned above.

The jumper wire must touch the Back of this connector.
(Jumper wire has to go Approximately 3/8ths of an inch, down into the socket hole.
.375 inches)

Moving on........

The other leg of the U-shaped jumper wire, goes down into ANY socket hole with a Black wire in it.
ALL Black wires are Ground wires. (Negative)

[This is a DC circuit. There is a Positive, and a Negative.
ALL power wires are Positive wires. ALL Black wires are negative wires. { Ground ]

The Soft Power On circuit uses 5 Volts DC.
In comparison two D cell flashlight batteries produce 3 Volts DC.

NOT stating there may be a small spark!
It's just the way electricity works.
For this reason you may wish to wear a glove, on the jumper wire hand.

The contact period made is no more than 2 seconds.
The Power On switch is a Momentary Contact Switch.

IF, the Power Supply turns on you have a bad Power On switch.
IF, the Power Supply does NOT turn on, you have a bad Power Supply.

The Power Supply in your computer is a Converter.
It converts HIGH AC voltage down to 3 LOW DC voltages;
3.3 Volts DC
5 Volts DC
12 Volts DC

EACH one is a Voltage Power Rail.

Orange wires are 3.3 Volt wires
Red wires are 5 Volts
Yellow wires are 12 Volts
(ALL Black wires are Ground/Negative wires)

EVERY wire that is Orange, is a 3.3 Volt (DC) wire.
ALL Orange wires go back TO the Power Supply.
They all connect TO the 3.3 Volt power rail, in the Power Supply.

EVERY wire that is Red, is a 5 Volt wire.
ALL Red wires connect to the 5 Volt power rail, in the Power Supply.

The same can be said for All Yellow wires.
ALL Yellow wires are 12 Volt wires.
ALL Yellow 12 Volt wires connect to the 12 Volt power rail, in the Power Supply.

IF, just one voltage power rail is weak, the computer will NOT work.

A) If ALL of the LED's were on at once, they would use less than 1 Watt of power.

B) EACH fan uses 2 to 3 Watts of power.

C) A typical Processor (CPU) can use 51 to 130 Watts of power.
Just depends on what CPU (Processor) it is.

[LED = Light Emitting Diode. It is redundant to refer to it as an LED light. That is saying it is a Light Emitting Diode light ]

That is why you may see LED's light, and maybe fans spin, but no computer working.
NOT enough power to turn the Processor (CPU) on...........

[Just in case you get this far, and this happens]

http://www.directron.com/atxswitch.html

The above ATX power on switch, is used in a LOT of desktop computers.

The Power On button is an assembly. it has the Power On switch, inside it.

For additional questions please post in a Comment.
Or click on Reply at end of solution.

Regards,
joecoolvette

Yes, it could be the Power On switch.

However I do have to ask how do you know, the Power Supply is good?

Did you use the unit on another computer, and it worked?

Did you test the 3 main Voltages?
3.3 Volts, 5 Volts, and 12 Volts? (All are DC Voltage)

Reason?

1) If ALL of the LED lights were on at once, they would use less than 1 Watt of power.

2) EACH fan uses 2 to 3 Watts of power.

3) A typical Processor uses 51 to 125 Watts of power. Just depends on what Processor it is.

This is why you could see LED lights light, and fans spin, but no computer operating.
NOT enough power for the Processor.

Yes, due to your statements there is NO power, period.
Just wondering how you came to the conclusion, the Power Supply is good.

Moving on......

Suggest perform the simple test to see if the problem is the Power On switch, or Power Supply.

This involves bypassing the Power On switch.
Does NOT involve the Power On switch itself.
Does NOT involve any cutting, or splicing of wires.

The main power cable going to the motherboard, is a
24-pin ATX main power cable.
Here is a general example of the power cable, and it's respective connector on the motherboard,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

[Note color of connectors does NOT matter]

Look at the photo to the Right. Main power cable needs to be plugged into the motherboard. Computer plugged into power.

The BACK of the main power cable's connector, is where the wires go in. It is the Back if the connector we will be dealing with.

The Green wire you see is the Soft Power On wire. Abbreviated as PS_ON.
ANY Black wire you see is a Ground wire.

Use a jumper wire to briefly connect the Green wire, to ANY Black wire.
The preferred jumper wire is a paperclip, straightened out; then bent into a U-shape.
Turn the U shape over.

The top of the U is wrapped a few times, with black plastic electrical tape. This taped area is for your fingers, and thumb to hold onto.
The 'legs' coming out of the bottom is what we will be using.

One leg slides down into the back of the main power cable's connector, in the socket hole with the Green wire.
Slides RIGHT NEXT TO the green insulation of the wire, and down into the socket hole.

Has to slide in far enough, to touch a female metal terminal connector. Every wire going into the connector of the main power cable, ends in a female metal terminal connector.

Jumper wire must touch it. Depth? Approximately 3/8ths of an Inch.
(9.52mm)

[Just for edification, a look at the female metal terminal connector,

http://www.mcmelectronics.com/product/28-9420&utm_medium=Affiliate&ref=cj&utm_campaign=CommissionJunction&utm_source=CommissionJunction

Looking at the Middle photo on the Playtool link above, shows you the Front of the main power cable's connector, and the opening of the female metal terminal connectors. Look like small brass rings, or squares ]

The other leg of the jumper wire slides down into, ANY socket hole with a Black wire in it. Has to touch that female metal terminal connector, also.

Contact period is no more than 2 seconds. (The Power On switch is a Momentary Contact Switch)

Shock Hazard:
The Soft Power On circuit, that pushing the Power On button (Switch) activates; uses 5 Volts DC.
In comparison two D cell flashlight batteries produce 3 Volts DC.

Not saying there may be a small spark. That is just the nature of electricity when two contacts touch. For this reason you may feel safer of you wear some sort of glove, on the jumper wire hand.

[Your power supply is also known as a PSU.
Power Supply Unit.
It is also an SMPS. Switched-Mode Power Supply. That is the power supply technology that is used.
Just wanted you to know if you see this terminology used.

Your Power Supply is a Converter. Converts the high 100 to 240 Volt AC electricity, (Depending on country), from your home or business; into 3 low DC Voltages;
3.3 Volts DC
5 Volts DC
12 Volts DC ]

Using the jumper wire;
Power Supply comes on? You have a bad Power On switch.
Power Supply does NOT come on? You have a bad Power Supply.

Power Supply comes on but no computer?
The next thing to check is those voltages stated above.
3.3 Volts, 5 Volts, and 12 Volts.

ALL Orange wires are 3.3 Volts
ALL Red wires are 5 Volts
ALL Yellow wires are 12 Volts.
ALL Black wires are Ground wires.

Using a multimeter I can guide you in testing.
(If you do not have a multimeter, consider an economical model.
Price averages $5 to $12.
Auto parts stores carry them, but usually higher priced.
I have seen them on checkout aisle racks, in major discount stores.
(States)

POWER is the first thing to check. Then onto the Ram Memory.
[Ram Memory module/s ('Stick') are removed, gold plated contact pins cleaned with a pencil eraser, eraser dust removed with air, Ram Memory module/s reinstalled ]

Motherboard has been replaced. Scary thing is, you do not know if it is any good. Just being new means nothing. You can get a bad new motherboard. (Especially if it isn't from a reputable dealer)

Testing the CPU of course, requires a good motherboard, power supply, and ram memory.
You should at least get the P.O.S.T. (Power On Self Test)
BIOS Setup should come up.

Awaiting reply post back in a Comment

Regards,
joecoolvette

check connections and if still nothing then the power supply may need to be replaced. Not hard to do,maybe takes 10 minutes to replace one. if you do change power supply contact me and i will help you through it. Not hard to do at all.

Test whether it is the Power On switch, or the Power Supply. Since the LAN card bit the dust, you may be looking at a worse problem, though.

Bypass the Power On switch.

If the Power Supply comes on, the problem is the switch.
[One generic ATX Power On switch, that I have found fits many computers,

http://www.directron.com/atxswitch.html

If the Power Supply does not readily come on, the problem is the Power Supply.

To bypass the Power On switch, you will be using a jumper wire on the
24-pin ATX main power cable connector.

Looks like this,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

(Not necessarily the same color, and isn't located in the same position on your motherboard, as shown in the link)

Motherboard orientation:
Processor to the top, Ram Memory slots to the right.

The 24-pin ATX main power cable connector on the motherboard, is to the near right, of the number 4 Ram Memory slot.

In case you do not have the Owner's Manual, for your Inspiron 530 desktop computer,

http://support.dell.com/support/edocs/systems/inspd530/en/index.htm

On this page left-click on -
Owner's Manual - View - Download - (HTML 3.44MB)

Left-click on - Removing and Installing Parts
Left-click on - System Board Components
(System Board = Motherboard)

Number 7 - main power connector (ATX_POWER), is the
24-pin ATX main power cable connector, on your motherboard.

Referring back to the Playtool link, you will see a wire with Green insulation on it.
This is the Soft Power On wire. (PS_ON)

A jumper wire is used to connect it to ANY Black wire.
ALL Black wires are Ground wires.

[This is a DC circuit. There is a Positive, and a Negative.
A Ground wire is a Negative wire.

The green Soft Power On wire, is a positive wire containing 5 Volts.
You are completing a circuit.
The Soft Power On circuit.
You are bypassing the Power On switch]

There is no splicing of the wires to connect the jumper wire.
The jumper wire will go down into the socket holes, of the 24-pin ATX main power cable connector.

One end of the jumper wire goes down into the socket hole, containing the green Soft Power On wire.
The other end of the jumper wire goes down into a socket hole, with ANY Black wire.

The 24-pin ATX main power cable, is connected to the 24-pin ATX main power cable connector, on the motherboard.
Just as shown in the photo to the far right on the Playtool link.

The back of the 24-pin ATX main power cable's connector, is where the wires come in.
(The front of the power cable's connector is plugged into the motherboard)

I use a jumper wire that is approximately 3 inches long. (7.62cm)
An insulated wire. Both ends of the insulated wire are stripped of insulation, approximately 1/2 inch. (1.27cm)

One bare end of the jumper wire, goes down into the socket hole of the Green wire. Right next to the wire.
It has to go pretty far down in there.

At the end of each power wire, going into the 24-pin ATX main power cable connector, is a metal terminal pin. (Actually is a round hollow metal pin)
The jumper wire's bare end Must touch that metal pin.

The other end of the jumper wire, goes down into ANY socket hole with a Black wire.
(ALL Black wires are Ground wires)

Power Supply (Computer) plugged into power, the jumper wire is inserted.
The contact is a very BRIEF one. No more than 2 seconds.
(The Power On switch is a Momentary Contact Switch)

I suggest you also check the 12 Volt power rail. Check it with everything plugged in, inside the computer, and the computer on.
You need the Power Supply to have a load to get an accurate test.

There are 3 Voltage power rails in the Inspiron SMPS.
(Switched-Mode Power Supply, or just Power Supply for short)

A) The 3.3 Volt power rail
B) The 5 Volt power rail
C) The 12 Volt power rail.

The main one to check is the 12 Volt power rail.
[Orange wires are 3.3 Volt.
Red wires are 5 Volt.
Yellow wires are 12 Volt ]

The Positive (Red probe lead of the multimeter, is connected to any Yellow wire, coming out of the Power Supply.
The Negative (Black) probe lead of the multimeter, is connected to any Black (Ground) wire.

See if there is an unused standard 4-pin Peripheral power cable.
It has 1 Red wire, 1 Yellow wire, and two Black wires.
Connect to the Yellow wire, and to one of the Black wires.

http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral

[Multimeter function set to DC Volts. If it has it, set it to the 0 to 50 Volt scale]

11 to 13 Volts is Okay, but I prefer the voltage to closer to 12.
11 Volts indicates it's time for a new Power Supply.

If the pc is not booting up, i think the culprit is memory. Just pull out the memory module and clean the connecting edges and put it back and restart. If you have 2 ram modules, first try to switch on the pc with one ram, or try switching the modules to other memory slots.
Hope this helps ..

Test the Power Supply first.

If you have a multimeter, use the Positive (Red) probe lead to connect to the power wire to be checked.
The Negative (Black) lead connects to ANY ground wire. (ALL Black wires are Ground wires)

Three main voltages are produced by a personal computer Power Supply.
1) Orange insulated wires are 3.3 Volt
2) Red wires are 5 Volt
3) Yellow wires are 12 Volt.
(Again, ANY Black wire is a Ground wire)

Or use an economical power supply tester.
One example,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5250576&CatId=5471

You are making a connection from the green Soft Power On wire, to any Ground (Black) wire with that jumper wire.

Using an HP Pavilion A1330E desktop computer for an example,
we can see that the main power cable is a 24-pin ATX main power cable.

This is readily shown by looking at the motherboard,

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00496280&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&lang=en&product=1829044

Scroll down to the motherboard illustration, and the motherboard photo underneath the illustration.

This is the pin-out for a 24-pin ATX main power cable, and connector,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

The Green wire (Pin 16) is the Soft Power On wire. The other end of the jumper can touch ANY Black ground wire.

1) ALL the lights use less than 1 Watt of power.
2) EACH fan uses 2 to 3 Watts.
3) A typical Processor can use anywhere from 51 to 125 Watts. Depends on what Processor it is.

The three Processor options for the Pavilion A1330E are, (Socket 939 style),

A) AMD Athlon 64 X2 4800+
B) AMD Athlon 64 4000+
C) AMD Sempron 3200+

The Sempron 3200+ can use up to 62 Watts
Athlon 64 X2 4800+, 110 watts, and Athlon 64 4000+ can use up to 89 Watts.

Point?
You have nothing but the motherboard plugged in, and the Power Supply takes a 'nose dive'.
Power LED turns off.

Bad Electrolytic Capacitors in the Power Supply.
Replace power supply.

What causes this?
1) Most computer failure can be attributed to the inside of the computer is dirty, as well as the Power Supply.

When the cooling components of the Power Supply, (Fan, and internal Heatsinks), are clogged, the cooling capacity drops tremendously.

Heat = Wasted Energy

The Power Supply tries to keep up with the call for power, and eventually components inside the Power Supply fail.

A can of compressed air for computers, used on a regular basis as needed could prevent this. (Observe Anti-Static precautions Before placing hands inside computer)

2) Cheap quality power supply.
Saves the computer manufacturer money.

i have had the same problem it is a very simple way to fix you need to unplug the main power that goes to the motherboard and use a paper click to jump it and then quickly plug it in.
im sorry but i do not remember which 2 slots to use the paper click on but i know 1 was black and when you unplug your pc you will have to repeat this process each time

You check the power supply using multimeter. but before everything make sure the you are getting power from the power outlet.

Here is how you can check the power supply with multimeter

If the wall outlet and the power cord are good, make sure the connection at the motherboard is secure. Then you may have to face the fact that the power supply itself is bad. If you have a multimeter, you can test the power supply output before purchasing a new one. Simply follow these steps:

1. Turn off the PC, but do not unplug it. Open the system unit. Set the multimeter to read DC volts in the next range higher than 12 volts. Locate a power connector similar to the hard drive (or CD-ROM drive connector that is unused) and turn on the PC.
2. You can also unplug a drive connector and use it. Turn on the PC and insert the BLACK probe into the power connector on one of the BLACK wires. Touch the RED probe to the YELLOW wire on the power connector.
3. The multimeter reading should be +12 volts. Now touch the RED probe to the RED wire and the reading should be +5 volts. If no readings or different readings occurred, you’ll have to replace the power supply. If the readings were correct, you should check the P8 or P9 connectors at the motherboard. These connectors may also be named P4 and P5. To check these connectors, perform the following:
   • Insert the BLACK probe into P8 at one of the BLACK wires. Insert the RED probe into the P8 connector at the RED wire. The reading on the multimeter should be +5 volts.
   • Check the power going to the motherboard connections by inserting the RED probe into P8 at the YELLOW wire and you should get +12 volts. Leave the BLACK wire touching the BLACK wire at the P8 connector. Check the BLUE wire and the reading should be a -12 volts.
   • Now move the BLACK probe to the BLACK wire on the P9 connector. Test the WHITE wire by inserting the RED probe and the reading should be -5 volts. Check the RED wires on the P9 connector and you should get +5 volts on each red wire. You won’t get exactly 5 or 12 volts, but the readings will be very close, such as 5.02 volts.
   • If the Power Supply is a couple of volts off in either direction, such as when the RED wire should be reading -5 volts but it reads -8 volts, or if there are no readings, replace the power supply.

change your SMPS .it is faulty.

May sound strange, but is the power supply switch in the correct position?
If the button is pressed, makes your continuity test, and not even the fans come on, check that the switch jumper has not come loose from the motherboard, and finally, if the motherboard is plugged in and no fan comes on when you push the power button, there may be chipset damage from an electrical surge or overheating.
In this case, a new mobo is your only option.