HELP! PC in constant reboot

carl0s

carl0s

carl0s

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Uk
My son uses my old PC and he hadn't used it for 2 days, when he went to turn it on, it was completely dead.

No power, it wouldn't boot and the fans wouldn't start.

I assumed it was the PSU, I got a new one, no change.

I then purchased a new CMOS battery and replaced it, which gave us power! The fans spin, including the CPU and PSU fans. But then they stop, and then restart again 5-10 seconds later.

It's stuck in a constant loop and I can't get a display on the monitor.

Other things I've tried, removed Ram, Gfx card to boot from mobo, changed the PSU cables, tried to short the mobo using a screw driver on the power on pins and unplugged the HDD's and DVD Drive. I left the battery out for half an hour to reset the CMOS but no change either.

I'm currently out of ideas. I'm leaning towards the CPU as I don't believe there's much else I can do.

Here's the current setup
  • Team Group Vulcan RED 16GB (2x8GB) DDR3 PC3-17100C11 2133MHz Dual Channel Kit
  • PowerColor Radeon RX 580 Red Devil 8192MB GDDR5 PCI-Express Graphics Card
  • Gigabyte Z77X-D3H Intel Z77 (Socket 1155) DDR3 Motherboard
  • Alpenföhn Matterhorn Pure Edition CPU Cooler (Socket 775 1155 1156 1366 AM2 AM2+ AM3 FM1 FM2)
  • Intel Core i5-3570K 3.40GHz (Ivybridge) Socket LGA1155 Processor (77W) - OEM
 
Have you changed the thermal paste? And are the CPU cooler fans working? I wonder if the CPU is overheating.
 
Try taking the CMOS battery out, turn the power supply off (just turn the plug off or whatever) and try starting the PC a few times then wait 15 minutes, so it's completely discharged.

Then try it.

That CPU/motherboard is pretty old, these things don't last forever, my money probably more on the motherboard has just died of old age.
 
Hey, so re did the thermal paste, tried changing the cmos battery. No change. It's in a constant loop of rebooting every 2-3 seconds. The fans are on then off. Really frustrating.
 
carl0s said:
It's in a constant loop of rebooting every 2-3 seconds. The fans are on then off. Really frustrating.
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Sounds like something is being shorted.
I would unplug all usb devices
Disconnect hard drives/SSD and remove the gpu. just leave CPU mobo and ram. Use the integrated GPU to see if you get a post.
 
carl0s said:
I built this over 10 years ago, so no idea what's happened to it

What are my best options here?
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well, definitely the internal usb 3 connector is unsalvageable unless you have a microscope and very deft hands

have you tried running just the cpu/mobo/ram alone (obvs with the psu) to see if it posts - ie nothing else connected to the core components except a monitor
 
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tamzzy said:
well, definitely the internal usb 3 connector is unsalvageable unless you have a microscope and very deft hands

have you tried running just the cpu/mobo/ram alone (obvs with the psu) to see if it posts - ie nothing else connected to the core components except a monitor
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Yes I've tried that, unfortunately no luck

I don't believe I can move the pins away from each other, I don't have the tools.
 
carl0s said:
I don't believe I can move the pins away from each other, I don't have the tools.
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freddie64 said:
It looks like some of the pins are missing anyway, so you could just use anything to separate the remaining pins as you will not be using the socket again.
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What Freddie said. The port is toast. I'd separate the pins and see if that fixes the problem in the first instance.

If it doesn't then I'm not sure I'd spend any money at all trying to resurrect this rig. It's so old nowadays you're probably better off getting something newer and more reliable.
 
carl0s said:
I don't believe I can move the pins away from each other, I don't have the tools
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Tweezers, tiny flat blade screw driver, metal nail file etc you don't need anything fancy you aren't trying to fix it just stop the pins touching so it doesn't matter if they snap off because you aren't using that port again.

That said if the 5V line is shorted I don't think the computer would switch on at all.

Has your son been messing with it what do the reset and power button headers look like are those ok?

Any of the capacitors on the mobo bulging?

SpellowHouse said:
I would try to get a used motherboard off ebay.
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Only if you can find one for a few quid, old stuff is often stupidly over priced.

This is 3rd gen stuff I'd be looking for 8th gen or newer mobo, cpu and ram bundle; there are refurb ex NHS / business PC's but the problem is they are often in SFF cases with small proprietary PSU's so you wouldn't be able to use your GPU or upgrade the PSU.


Another option is treat yourself e.g. buy an AM5 bundle for your PC and give him the bits outs of yours.


If its still DOA after sorting the pins it depends what he uses it for and whether you have a budget for an upgrade.
 
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