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| Thread ID: 139554 | 2015-05-22 00:50:00 | PC won't boot | Tony (4941) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 1401170 | 2015-05-22 02:43:00 | That's probably what I'll do. Mind you I just checked the PB tech website and I can get a Coolermaster 400w PSU (current one is 300w) for $63.25 or a Zalman for $79.35, so maybe I'll go with option 2. | Tony (4941) | ||
| 1401171 | 2015-05-22 04:23:00 | OK, I knew I shouldn't have messed around. :( I plugged my known working PSU into the old machine and when I hit power it behaved exactly like the problem one - fans whirr then everything stops. Which makes me think it is not a PSU problem. When I reconnected the good PSU to its own machine and pressed power - dead silence. Not a thing. It is behaving like the PSU that I thought was good and then didn't because nothing happened (if you see what I mean...). The connections I made were the 24-pin main power and the CPU power. I figured that would be enough to start things up, even though it wouldn't be able to get very far. Is there anything else required? Why has my "good" machine stopped working when I reconnected? Fortunately I have a laptop as well or I would be totally stuffed. |
Tony (4941) | ||
| 1401172 | 2015-05-22 04:38:00 | Phew! Got my main PC back. I had the CPU power plugged in the wrong way round - which I didn't think was possible.:confused: Anyway, that's one less thing to stress about. It certainly looks like it is not a PSU problem on the other PC - any other ideas? |
Tony (4941) | ||
| 1401173 | 2015-05-22 05:10:00 | If its not the PSU, then try changing the CMOS battery, if its flat all sorts of werid things can happen. But before buying anything theres a few tests you can do. In no particular order: Locate the leads from the front panel, disconnect from the motherboard taking a flat bladed screwdriver, short/touch the + & - Pins that the power Button attaches to, if it fires up - you have a faulty Switch. Make sure the heatsink on the CPU has not come lose or moved, if the seal has been broken that WILL stop the PC from booting (had one do that yesterday here) Reseat the Memory, but first remove all memory, and try to power it up, it should complain about no memory (but not always) try different memory if you have some (doesn't matter what size its only to test) Carefully check ALL the USB ports, make sure the plastic tab in the port has not broken out, and one or more of the pins have been bent and touching the casing, causing a short. If they have and they are on the front of the PC, unplug from motherboard. If on the rear ports, then you may have to pull out the pins, or straighten/move from shorting. If after all that, and its still not working I'd take the Board out of the PC, put on the bench, with only the CPU/memory/ KB & Mouse, PSU and monitor connected, again short out the power pins. If it fires up and shows the BIOS or complains about no Drives/bootable device, there is a short circuit someplace between the Board and the case, or some external device or HDD/ optical Drive is causing problems. If its still not going good chance the Board has gone where ever they go when they Die. |
wainuitech (129) | ||
| 1401174 | 2015-05-22 05:11:00 | unplug all drives and usb devices etc that don't have to be connected, make sure the cpu fan spins when it tries to start and if there's a case fan connected check that as well. Sometimes a usb device prevents booting, as can a faulty drive. and a fan that isn't spinning. After that try resetting the BIOS with the link and see if that heplps. Look for signs of failed components and bulging capacitors. If using graphics card try swapping it for onboard or another card if you can. If it starts working at any point put things back how they were 1 thing at a time so you know where the problem is not all at once. |
dugimodo (138) | ||
| 1401175 | 2015-05-22 05:26:00 | Thanks Wainui and Dugi - all good suggestions. I'll try the CMOS battery first. Wainui, I'd be surprised if it is any of the physical things you suggest - although I will check - as the PC has been just sitting there since it was last powered on successfully. It has just occurred to me that I had a power cut last night, and I wonder if something got fried when the power went off or on, although the on/off on the PSU was off. I've just had a quick look and there are no bvious bulging capacitors that I could see. I'll report back. |
Tony (4941) | ||
| 1401176 | 2015-05-22 08:39:00 | It has just occurred to me that I had a power cut last night, and I wonder if something got fried when the power went off or on, although the on/off on the PSU was off. Yep it can still cause problems, as long as its plugged in to power, on or off. Many moons ago, when most people were on dialup, one of my customers went away on holiday for a month, they asked me if it was wise to unplug the PC from the mains power - Wouldn't hurt. While they were away there was some rough weather, lots of electrical problems in the area, when they got back the modem in the PC had Fried, it was the only thing still plugged in as they couldn't get the plug out,something came through the phone line and zapped it. |
wainuitech (129) | ||
| 1401177 | 2015-05-22 09:49:00 | It's a chocolate fish to Bryan and Wainui - it was the CMOS battery. Since my first PC in 1985 that is the first time I've ever had that problem. Probably an indication of how old the system is. Thanks to everyone for the help and suggestions. |
Tony (4941) | ||
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