Have found memory modules - now problem with On/Off button!

Barbusa · 26 Jan 2006

Further to my earlier posting, I would like to thank all concerned for their help.

I have now managed to find another 128MB SDRAM PC100 module that works but when I turned on the pc earlier today - Nothing.

As I have renewed the power supply and checked the connections to the motherboard I can only think that when I upgraded the CD Rom drive (situated just above the On/Off button) I may have damaged the part in some way.

If it is not that, what else could it be, unless there is a problem with the board.

Before starting again with a new case, is there any way that I can ascertain, for definate, what the cause of the problem is and, if it is the switch, is it possible to replace it or fit another?

Again, any help/advice would be much appreciated.

Igorian · 26 Jan 2006

Is it a locking power switch with an AT PSU or a momentary contact with an ATX PSU?

Barbusa · 27 Jan 2006

I think its the latter.

The button is on the front of the tower and I can see that when it is pressed it only makes a momentary contact with the component immediately behind it.

Softus · 27 Jan 2006

Are there any LEDs alight on the motherboard, normally? If so, are they lit now?

If not, then do you have a meter with which you can check that the PSU is providing a supply to the motherboard?

When you fitted the memory, how much pressure did you exert? Did the motherboard flex much? If so, then two things are possible - (a) the flexing can damage tracks on a motherboard, irreperably; (b) solder spikes on the underside can touch the metal chassis of the case and cause a short.

These are rare faults, of course, but I might as well mention them up front.

Barbusa · 27 Jan 2006

No, there are no LED lights on the motherboard.

I am going to borrow a meter tomorrow to check the psu as advised.

I don't think the last two points apply as it was working fine until I put in the new CD-Rom drive.

Igorian · 27 Jan 2006

If it's an ATX supply, then locate the two pin jumper power connector on the motherboard. Remove the wire (it could be any colour, but commonly black/white) and then short the pins on the motherboard momentarily. If it powers up, it is the button, but this is a rare case. It's always possible that this wire is not connected/came loose while you were working on the system.

You said that you replaced the PSU already. Was the other one dead? If so, then it's possible that this one is too or has been incorrectly connected (almost impossible with ATX). If it's dead, then something obviously killed it and you should revert to a basic build to find the faulty item.

When testing your ATX supply, make sure it is under load. They (generally) don't like running without.

Softus · 27 Jan 2006

When you added the optical drive, did you just use a previously unused position on an existing IDE cable, or did you have cause to make a connection at an IDE port on the motherboard? If the latter, then how much force did you need to exert (etc. etc.)...

Barbusa · 27 Jan 2006

I did have to change the connections around on the motherboard as the existing 'ribbon' cable was not long enough!

However the connectors fitted together very smoothly. I just needed to press lightly to secure the fixing.

Softus · 27 Jan 2006

Light pressure should not be a problem. It's worth following Igorian's suggestion, which is to confirm that the switch is (a) making contact and (b) still connected to the motherboard.

kendor · 29 Jan 2006

Is the power supply you replaced with exactly the same as the original? and if so is it man enough for the job? ie have you added to the original spec of the PC since you got it?

Barbusa · 12 Apr 2006

The new power supply wasn't exactly the same as the original which is an unsusually small one with an external fan.

I have now, at long last, managed to find a similar one which has been tested and is ok.

I have connected the new one but, alas, still no joy!

Igorian suggested the following:-

Locate the two pin jumper power connector on the motherboard. Remove the wire (it could be any colour, but commonly black/white) and then short the pins on the motherboard momentarily. If it powers up, it is the button, but this is a rare case. It's always possible that this wire is not connected/came loose while you were working on the system.

The problem is that I cannot identify where this 'two pin jumper power connector' is located.

I have found socket that seems to connect to the front panel switch but this has red, black, white, blue, green and orange wires going into one end of the connector and a single black to the other one.

Is this the one?