K8N Neo2 Bad Caps?

[tomsullivan]

Over the past few weeks I have had my K8N Neo2 Platinum / Opty 175 combo reboot on me a couple of times with no apparent reason. I ran memtest and found no problems, so put it down to power-supply glitches.

Last Wednesday it failed to POST when switched on, but when switched off and on again, it successfully went through POST. Come Friday morning, the system would not POST at all. No fans, no hard disks spinning, nothing, except the power light on the front panel that would come on for a few seconds and then slowly fade.

The PSU is an Enermax INFINITI 720W SLI and has been tested with other mobos and works fine.

A thorough visual inspection shows no signs of any bulging or leaking caps.

The caps are:
6.3v 1800uf Rubycon
15v 1500uf Rubycon
These are located close to the CPU and I assume they are associated with the VRM.

6.3v 1000uf OST
6.3v 470uf Teapo
These are mainly in and around the DIMM sockets, with one of the Teapos to the side of the CPU socket.

The remainder are 10v 470uf with the brand marking KZE and are dotted around other parts of the board.

Any ideas or suggestions would be most welcome

[tomsullivan]

Re: K8N Neo2 Bad Caps?

anyone?

[kc8adu]

Re: K8N Neo2 Bad Caps?

clear cmos.
test parts in another mobo.
sub known good psu,ram,proc.

[chipper]

Re: K8N Neo2 Bad Caps?

This always seems to happen to the best of us who are trying out new things with a new mobo. One thing I found is that most PSU's molex connectors are not any good.
What I mean is that they mess up. Here's how :
Each time , especially when you are busy making a system up , when you plug-in and un-plug the molex connectors you are opening the tube ends inside the plug end. If the tubes become too loose , then the hard drive starts to stutter or even disconnect.
I had this happen a couple of times , it causes no boot at startup. So , you press F8 to enter the bios or whatever (delete key) and you see that the bios is showing you that the hard drive is not being detected.

What you have to do is to get a very small flat head screw driver and slip it between the molex plastic casing and the metal tube end of the pin connectors , and close the gap that is causing the looseness. Once done , you go back to the bios at startup and you will find that the hard drive is then "recognized" , and ready to pass the bios startup into booting to desktop. They fail to complete boot sequencing if your Windows Setup Disk is not in the CDRom or floppy (autodetect). Usually the system will restart over and over. But this is really , a short circuit.

This happens also when your hard drive is normally getting too hot , it causes the metal pins to become more soft , opening them easier. They actually are warping.
The RocketFish 750 watt PSU , has plastic "pincers" which are like paperclips , above and below the molex connector , when you squeeze them the connector is moved back , out of the hard drive or drive pins. This stops any need to "rock" the molex connectors back and forth to disconnect them when needed.

I would imagine that higher rated power supplies wreak havok upon a hard drive moreso than others , since there is more current flow or amperage. Also , connecting and reconnecting the hard drive will cause all sorts of trouble , even cause entire operating systems to fail or worse , the hard drive will fail because it is usually going to be overheated when this occurs. Always shut the system off when disconnecting molex connectors.

Tapping on your case can expose this problem , and the problem will happen if your case fan makes anything rattle , rattles should be stopped to ensure that your major connections to anything are not loosened because of it. It also makes tie-downs an issue of any connectors. It's what can be called "arcing".

[chipper]

Re: K8N Neo2 Bad Caps?

Sorry , long thread , you should also check the fit from the PSU (20-24pin) to the motherboard post-pins for good connection in the same way. Check all of them.