Help - PC Boots & Reboots Endlessly (But No Post)

[UseItNow]

Hi folks, I've got caught up in a hardware fault at the moment, the first serious concern in over 4 years and would appreciate any help/pointers in diagnosing what's wrong with the system. Worse thing is that I don't have any similar hardware at the moment to test out the components, to write one off at a time.

I've been keeping an eye on these threads over the last couple of days with similar headaches, here:
http://forums.hexus.net/help-technic...p-nothing.html
http://forums.hexus.net/hexus-hardwa...itor-help.html
http://forums.hexus.net/help-technic...ep-no-usb.html
http://forums.hexus.net/help-technic...post-help.html

Anyway, here's the specification: (Never been overclocked, all stock settings!)
Intel Core2Duo E6750
Gigabyte P35C-DS3R Rev1.0 (Original F2 Bios)
Crucial Ballistix PC2-5300 with 3-3-3-12 Timings as per guidelines
Sapphire HD2600XT 256Mb GDDR3
Hitachi HDD
Corsair HX520W

Note: I have always used a UPS with this system, I just do with my systems)


Now the problem:
The system has been working without a glitch for nearly 2 years when on starting it, it decided to go into a rebooting cycle. Basically it will start up, seem to run for a few (4-5?) seconds, then power down and reboot again. The system upon starting/rebooting will display no signal on the monitor, thus NO POST screen! (Have tested monitor on an older system, it's OK)

However, the fans connected on the Antec case run, the VGA fan spins, the CPU cooler fan spins up.
I must also stress that upon last usage my younger sibling did notice a post screen stating that the Award BIOS was trying to recover the BIOS from the hard disk. What? Why?


What Have I tried?
Well first, I thought maybe the memory had had it but because it won't POST, I can't run Memtest, nor do I have spare hardware of a similar spec (SKT775, DDR2, ATXv2.2 PSU, PCI-E VGA) to test the parts.

So I decided I would have to switch out the 2 DIMMs and test 1 socket at a time with each stick, whilst clearing the CMOS, NO RESPONSE TO THAT, NO POST & IT STILL REBOOTS CONTINUOUSLY!
Please note as my case, an Antec 900 doesn't have a speaker, I purchased a Switch Test kit from Maplins and added the speaker to the motherboard, no beeps from the sounds of it.

So now I've decided I've got to cut it down to what may be the culprit by purchasing some parts, AAAHHH!

First thing tomorrow I'll order a PSU Tester, a new PSU (anything you could recommend thats cheap but has the connectors needed?), a DDR2 stick, a new cheap motherboard - are the Nvidia 680i chipsets any good, heard alot of issues with them, that's why I ask but for the money they are feature packed (any brands to avoid?) and a cheap PCI-E VGA card! (Again, any recommendations, links welcome!)


Minimum hardware to boot to test?
Whilst all the parts are to be ordered and delivered I thought maybe I could do some further testing, so, essentially what is the minimum hardware required to boot (M/B, CPU, RAM, VGA)?
With the minimum parts could I boot the system (M/B, CPU) with/without the memory/graphics card to see if there is any POST and also rule out the items (Memory & VGA)?
Finally, would booting without the VGA and/or Memory possibly cause any further harm to the components, I ask if it's so I think I'll pass.


Folks, I appreciate you reading my posted thread and would be very grateful for all the help you provide, many thanks.

[Splash]

I think you're headed down the correct route - testing with no RAM or VGA would help diagnose and certainly isn't going to cause any furher damage, but I personally think you're looking at a fault with either Mobo, CPU or PSU. Or a short - can you set the system up outside the case to rule a short out?

[ACE_RIMMER]

Don't know if you've tried it but I've had a few systems that did the same and they were power button faults shorting out, worth a try and one of the easiest things to try, just unplug the power button from the board and see if it continues, if not, short the 2 pins and see if it switches on ok. If the power button is held in it'll sometimes power off after a few seconds then power on again in a loop, same if the button is damaged "sometimes" .

Just a remote possibility but you never know

[roorooroo]

I've heard of this problem with the DS3R mobo..from reading various posts on various forums i don't think anyone had the definite answer. If memory serves i think some people had success from completely removing the cmos battery instead of just clearing cmos (leave it out for a while)..it's ages since i read up on it but give it a go..it's worth a try.

[Clockedtohell]

I had this very problem and it turned out to be a PSU issue both times. First time was on a IP35 Abit board, basically a compatibility issues (although the combination had been fine for months). Then on a different rig, turned out to be a failed PSU.

When I had this issue I was advised to rebook and hold down F12 (chap from Cyberpower), this causes a full reset of some description to the BIOS (don't ask me how) and is similar to removing the BIOS bat and unplugging from the mains....interestingly this has worked on two different rigs, The Abit mentioned and another based on an Asus Maximus Formula. After booting once the issue reocurred after it was shut down, it might give you a chance to get into the BIOS and check the voltages.

Normally if it's RAM, GPU or CPU you will get a beep code, so I'd see if you have another PSU knocking about or buy one of the PSU testers from Scan, I got mine free with a PSU, but I think they are only £4-£5 so a good and cheap start to fixing your problem. Try the PSU and see if it boots, if it does you know what the problem is. If not you then need to check the PSU connections to you components. I'm guessing it's not modular, but again check all of the connections. This is also a common problem.

Good Luck!

[UseItNow]

Folks, thank you for your replies, do apologise for being slow in responding.

@Splash
I've had some time to take out all the RAM, guess what there doesn't seem to be any beeps whatsoever, the machine still reboots. I've got to get around to taking out the system from the case to rule out a short.


With that said, I have one of the motherboard testing kits from Maplin (this: http://www.maplin.co.uk/Module.aspx?ModuleNo=98842). Does anybody else have one and how loud is the speaker? Also, the leads on the speaker are coloured black (presume +?) and white (presume -? labelled KSP?) Just want to make sure it's plugged in correct, however, plugged it in both ways, still no beeps.


@ACE_RIMMER
Will unplug the Power & Reset buttons of the case and plug in switch kits from Maplins to rule out the possible button short.


@roorooroo
Oh yes, I forgot you have the same motherboard (http://forums.hexus.net/hexus-hardwa...-problems.html).
The first thing I did was remove the CMOS battery, anyhow it doesn't look good from what's here:

Here:
[Resolved] Gigabyte P35-DS4 - constant reboot loop - PC Perspective Forums

Couldn't thank Phil for his link on his post, as the read was interesting and possibly something that might be exhausted later on. Thanks Mate!


@Clockedtohell
Yes mate, I thought the PSU might be knackered so bought one of the testers from Scan, it seems to indicate it's fine, however, do now have another PSU to test with to rule out PSU.
Will also attempt the F12 button on boot, it's also been mentioned to attempt the Insert key at boot too, will attempt them both.

Many thanks again folks for your replies.

[peterb]

Thos PSU testers aren't really worth it. They don't test the PSU under load, so while they will indicate if a rail is missing, they don't tell you anything about the capability of the PSU - the voltage on a rail could still be failing when it is under load. You need a multimeter and a dummy load (old car headlight lamp is quite good) to test it properly.

I am concerned by that comment that it seemed to be trying to reload the bios - which indicates that the bios might be damaged, which could cause the symptoms described.

[UseItNow]

Thos PSU testers aren't really worth it. They don't test the PSU under load, so while they will indicate if a rail is missing, they don't tell you anything about the capability of the PSU - the voltage on a rail could still be failing when it is under load. You need a multimeter and a dummy load (old car headlight lamp is quite good) to test it properly.

I am concerned by that comment that it seemed to be trying to reload the bios - which indicates that the bios might be damaged, which could cause the symptoms described.

I am aware that PSU testers aren't exhaustive in testing, so tried another PSU, same effect.
I presume it might be the motherboard too from that boot block? Hopefully, will find out later when replacing the motherboard with a new one, keeping other existing components to eliminate everything else.

THANKS AGAIN TO ALL.

[UseItNow]

Sorry, it's been a bit hectic but better late than never, yep, the board was faulty!

I returned it to Scan, it was tested faulty and replaced with a replacement board, unfortunately the replacement had a loose heatsink (damage in transit?), so another RMA and now I'm waiting for the replacements replacement.

Although I must admit Scan have been great to deal with from the start, was a bit concerned as it was my first RMA for anything faulty.