New build fails to power up

[orinoco]

I've finally decided that it's time to upgrade the old P4 machine, and the plan was to stick this lot into my old CoolerMaster case;

MSI P35 Platinum
Intel Quad Core Q6600
MSI GeForce 8800GT 512MB
2x Crucial 2GB Kit (4x1Gb in total) DDR2-800 RAM
Hitachi Deskstar P7K500 500GB 7200RPM S300 16MB
Hitachi Deskstar P7K500 320GB 7200RPM S300 16MB

and power it with a CoolerMaster 700W REAL POWER PRO MODULAR PSU

The problem is with that lot in the case and connected up, the thing just doesn't power up. I would get the standby LED illuminate on the mobo when power is applied to the PSU, then on hitting the power button I'd get power for a fraction of a second and then the system would go back to standby mode.

During that fraction of a second when there was power on the mobo all the fans started to turn [CPU + 4x 80mm case fans], the PCI LED next to the 16x PCIe slot [registering a card was inserted] and the status LEDs would light briefly and then go out with the standby LED coming on again.

As the box this lot got shipped in was damaged on arrival, I immediately thought there was a problem with the mobo [being nearest the damaged bit of the box] and returned it. A new one was shipped out and sadly that made no difference.

My next thought was the power supply that had an internal short. By removing the mobo from the tray, placing it on paper [to isolate it from the case] and only connecting up necessary things I thought I'd rule out a short to the case. Then I tried removing sticks of RAM 1 at a time, with no change. Then with 1 stick of RAM the opticals/floppy got removed, then the hard disks [one at a time] each time the same thing happened. I carried on removing stuff until...... I got to just the mobo and processor connected and the same thing still happened I thought it must be the PSU, so that's been returned and I'm awaiting a replacement for that.

I've ruled out the processor as being at fault, as the mobo status LEDs have a pattern that shows 'processor damaged or not installed correctly' and I'd guessed that would be shown if there was a processor fault.

However, the MSI manual got me thinking [being translated to English from the original Taiwanese it's easy to mis interpret the meanings at times], it said that the 12V ATX power should be at least 18A, the PSU delivers 4x 12V rails each at 19A so that should be fine I thought. On top of that the MSI has the newer 8 pin CPU connector and the power supplied to that comes from 2 separate 12V rails, which means that I have 38A total delivery. As well as the 8-pin CPU connector there is also a Molex connector on the mobo, and I'm wondering if that also needs 18A...? Sadly the PSU manual doesn't say which of the rails provides power to which of the modular connectors, so I can't tell if I'm over-loading the PSU by the way I'm connecting the modular connectors to that molex.

Has anyone here come across anything similar or have any suggestions that might help me? It's a new situation on me, I've built a few PCs in my time - but I'm by no means an expert - and this is the first time I've come across this situation. The other obvious question is where do I go if the new PSU leaves me in the same position I'm in now? Do I try a different mobo or change from the Coolermaster PSU to a different one? My budget is limited [which is one of the reasons I'm self building] so I can't simpy go buy a load of extra stuff to try.

Thanks in advance...

[ctal]

Thanks for your thorough description of what you've done -- much better than most people with comparable problems usually provide.

Are you sure that the molex on the mobo is for power input, rather than just being an additional place to connect something to a source of power? Or possibly a point to which a fan with a four-pin connector would be connected, so that the mobo could control and/or monitor it? If you are not sure, try connecting nothing to that molex and see what happens.

The only other suggestion I would make would be to avoid placing the mobo on paper. My concern would be the possibility of damage due to static electricity coming into contact with exposed circuit points. You don't want to put it directly onto anti-static material, either, because the material's slight conductivity might affect operation. If you want to run the mobo when it is not mounted in the case, I would put three or four metal spacers (or bolt & nut combinations) under some of the mounting points, and have them in turn resting on a surface which preferably would be anti-static.

Regards,
-- Al

[rjs735]

Additionally I would try just the cpu and 1 stick of ram and video card.

I also assume that the MB supports the quad processor without a new bios update?

This is the problem when you have a new build . You have to be able to sort thru the new components just like you're doing but without source of new parts to swap with.

I just went thru a similar event where I bought an new board 925XE chipset with a PCIe slot and a new PCIe Video card ( ATI Radeon x600gt) the video would not lite. SO I plugged it into another board that had a PCIe slot and it lit up. SO bad MB no because when I ordered a replacement it did exactly the same. So I ordered a video card made by the MB mfg. Got it plugged it in and the vidoe lite up. The new video was an Nvidia chipset.

The closest I can figure is when PCIe was implemented by different mfg they chose different routes. ATI chipset is a good chip set so is NVIDIA but sometimes one works and the other doesn't. I have since tried a generic NVIDIA and it also works fine. So I will use the Ati Radeon on some other build.

[ctal]

Also, I believe that some mobo's will not turn on if they don't sense a cpu fan. Is the cpu fan connected to the proper place on the mobo, or directly to some other source of power? Just a thought.

-- Al

[orinoco]

Thanks for the speedy replies.

Originally Posted by ctal

Is the cpu fan connected to the proper place on the mobo

Yup, it's connected correctly, when I hit the power button the blades start to turn, whether the sensor wire is good is another question, but there's definately power there.

Originally Posted by ctal

Are you sure that the molex on the mobo is for power input,

Where Power1 is the 8 pin ATX connector and JPWR1 is the molex. On top of that the molex is male, and male connectors are usually not carrying live power.

Those quotes from the MSI manual answer the question better than I could... I would have attached the manual to this thread, but it's too big!

Originally Posted by rjs735

Additionally I would try just the cpu and 1 stick of ram and video card.

I've tried that one too. I even tried disconnecting the power from the graphics card and got the expected high pitched whistle for the time the system stayed powered...!

[orinoco]

Well the good news is that the CoolerMaster power supply was the problem, the bad news was that the replacement still didn't help.

It would seem that the cabling of the 12V rails was such that booting the box overloaded something and the CoolerMaster PSU kept tripping out. I got a 1000W Jeantech supply from a local store and that was labelled and cabled in such a way that I could boot the PC.

Both had 4x 12v rails, the CoolerMaster was rated at 19A each the Jeantech was 20A each, but the modular connectors in the Jeantech were labelled so I knew which rail fed which output, the CoolerMaster wasn't. That Molex on the mobo has rail 4 all to itself, the PCIe and Mobo/CPU share rails 1 and 2 and the HDD/FDD/Opticals have rail 3.

And now for the bad news; the new PSU is 19cm [7.5"] long, and the space in the case for the PSU is only 17cm [6.7"]!

The case I have is a CoolerMaster ATC 201 B. Any suggestions for a new case greatly appreciated. All aluminium design, intake and exhaust fans [120mm are better as they will be slower rotating and thus quieter]. Preferably no fans on the sides as the case sits in a confined space with good front/back airflow, but not sideways.

I need;

2x External 5.25" bays - for opticals
1x External 3.5" bay - yep I still use a floppy!
2x Internal 3.5" bays - for HDDs

[Mankal3]

Check out the Lian-Li cases at newegg, I believe you can get what you want for 100 dollars