CPU RAM Motherboard Troubleshooting
power diagnostics sends you back here, continue following through the diagnostic steps.
LCD diagnostic done? If you haven't performed the video failure diagnostics for a dead screen yet, do so now. Remember that in the vast majority of laptop computers, the video processor shares the same physical memory modules with the CPU. If the diagnostic points to a video processor failure, make sure to search the Internet to see if it’s a characteristic failure for that model with a possible workaround, like reflowing the solder. Done overheating diagnostic? This is particularly important in the case of dead screen troubleshooting if the problem only occurs when the laptop is warmed up. All of the components in your laptop are subject to failure if the laptop gets too hot, including vital motherboard components, the CPU and the RAM. If your laptop is overheating and you ignore the fact, you might properly diagnose the component that is failing when it gets too hot and replace it, but unless that component was itself responsible for the overheating, you've treated the symptom without finding the cure. Swap RAM fix? Many technicians will start troubleshooting any dead screen or no boot failure by swapping out the memory, because it's easily done and it's often at fault. If you have two RAM modules installed you can try running one and then the other, and if you can borrow a compatible module from a friend, it will rarely damage their RAM to try it in your system. While we hate to recommend you go out and purchase a part just to try it out, a replacement memory module for your system may run as little as $20. If your existing RAM turns out to be good and the problem is solved later on, you’ll be able to install the spare, increasing your capacity and performance. For most home users who have never taken a laptop apart before, swapping the RAM is a good gamble before we get to taking the laptop completely apart.
CPU heatsink active? All modern laptop CPUs require a heatsink, and most of these are an active heatsink, with a fan on top, or a hood over the CPU heatsink with a fan blowing air through. Laptops offer heat and power management at both the operating system and BIOS level. You may be able to set the exact temperature in CMOS Setup for which you want the fan to come on or the system to warn of thermal overload and shut down. In the operating system, you can generally tweak the CPU settings so it consumes less power (resulting in lower performance and less heat) or for quiet operation, which limits fan usage.If you just installed a replacement CPU and powered the system up with no heatsink as a test, you may have damaged the new CPU already. If the fan on your active heatsink isn't spinning up, replace the fan and hope for the best. Make sure to confirm the new heatsink fan is operating after replacement since it could be the power point on the motherboard that's failed. You should never need to replace the heatsink itself unless you break the hold-down mechanism, since it’s just a chunk of metal. If you replace the entire active heatsink, make sure that it’s designed for your specific model, or it may fail to contact the CPU even with the proper application of thermal paste, guaranteeing failure.
Hear beeps? If you have a system that powers up, the next question is, do you hear any beeps coming from the laptop. If your motherboard doesn't have a dedicated piezoelectric speaker for beep codes, it will use the built-in laptop speakers. The beeps should come in repeated patterns, so many in a row, and then repeated. Write down what you hear and then head to Google and search for the translation of the code. If you hear an unending string of beeps, it's often bad RAM if the screen is dead, or a keyboard failure if the screen is live. Depending on the manufacturer, you might also get specific beep codes for CPU failure or video processor failure. Many beep codes have been abandoned since they pertained to non-user replaceable surface mount components. It never hurts to shut down and reseat the system RAM if you're getting a beep code. Runs stripped? Bench testing laptop motherboards is quite different from bench testing PC motherboards because laptops are engineered as a unit and it's not easy to run the motherboard out of the case. The option is to simply strip everything not essential for a live screen out of the laptop to ensure that there isn't a problem with a component that is putting an undue mechanical stress or electrical load on the motherboard. The RAM and the CPU need to remain installed, but you can remove the hard drive and the DVD drive, and if you're ambitious to take the whole laptop apart, you can try for a live screen without the keyboard or any non-essential daughter cards installed. You should always unplug the AC adapter and remove the battery while working on the laptop, but you'll have to plug the AC adapter back in again to attempt to boot.CPU swap works? If you still have a "no signs of life" situation with the motherboard powered up and stripped down, it’s either a motherboard component failure or the CPU. Swap in a known good CPU if you can get one dirt cheap or free, not forgetting to install a good heatsink and to connect the fan, even just for a quick test. You need to find a CPU that's supported by the laptop BIOS, it's not enough to find one that mechanically fits the socket, assuming the CPU isn't soldered into place! The only way to determine what CPUs are appropriate is to check your user manual or do a little research on the web. Think twice and three times about the value of your laptop before spending real money on a new CPU, since you’re just gambling the problem isn’t a motherboard failure. If your old CPU is bad and the heatsink fan is dead, it's a pretty sure bet that the dead fan caused the CPU to failure.
You can identify many motherboard component failures with a decent magnifying glass. They’ll show burnt or melted spots, discoloration, or be carbonized right out of existence. Some discrete motherboard components such as capacitors and power semiconductors are replaceable with a good soldering iron, though there’s always a chance they’ll pop again as soon as you power up if the fault lay higher upstream. Other surface mount components are barely visible to the eye, require an insider’s access to replacement parts, and expensive soldering equipment to attempt to install. There's no point in calling the manufacturer to price a new motherboard if you determine it's the most likely problem. Laptop motherboards are specific to the model and family, and the manufacturers charge you almost as much as a brand new laptop for most replacement motherboards. If the laptop is relatively new or beloved and you really want to keep it going,
the best option is to try to find a replacement motherboard on eBay from a pull, from another failed laptop with a different problem like a bad LCD. There's always the risk the replacement will be bad as well, but in shopping, you may find that a second hand working laptop of your exact model is available for less than you would have thought. You can buy it and move your hard drive over in a jiffy, but make sure you don't end up paying as much as the price of a new, superior notebook. Freezes on boot screen? Does the system power right up, give a happy beep or two, then freeze on the BIOS screen?
First try removing any external connections, including your networking, cellular modem or dial-up modem cord, printer cables, anything that wasn't attached to the laptop when you took it out of the box for the first time. If this allows the laptop to boot, the problem is either with one of the peripherals you disconnected (check by process of elimination) or with the software driver for that peripheral. Windows based systems may automatically start in Safe Mode after being powered down and rebooted if the problem was with a driver.Demands password? Does your system power right up and demand a password? We're talking about pre-OS load here (a BIOS screen password), not a Windows password. This normally pops up in a small text box in the dead center of the screen, which may be dark but for the box. Some newer laptops are equipped with fingerprint scanners or other biometric locks, but these give you the option to type in a password as a fallback. If you know that a password is set but you've forgotten it, you may be in for a headache. It's also possible that somebody in your family ended up entering CMOS Setup and set the password by accident. Unfortunately, if the machine is asking for a password on boot, it may also demand a password to access CMOS Setup in order to disable it. Check with the manufacturer's tech support and do a Google search to see if there's a workaround before taking the laptop apart. Desktop motherboards come equipped with the equivalent of a "Forget Password" jumper, but laptops usually aren’t that friendly. There's a good chance that the password is cleared by removing the RTC (Real Time Clock) battery that also preserves the CMOS settings.
You should search the web for instructions for your model, as it may involve a whole complex sequence of events, like removing the RTC battery, AC adapter and main battery and then holding in the power switch. OS load takes forever? Does the OS load take forever or does the system get as far as complaining about a missing boot drive, a bad disk, missing operating system, no boot partition, anything similar? If you get any of these messages, proceed to hard drive failure diagnostics. If the system doesn't freeze on the BIOS screen, but doesn't start loading the OS either, it could be a rapid overheating problem with a critical motherboard component, but the odds are still with software. One check is to change the boot order in CMOS to boot the DVD/CD drive first, and to try a bootable disc. If the disc boots and the laptop sits quietly without freezing up, the problem is with the hard drive or installed software.Random reboot? Does the system reboot itself for no apparent reason, either during the boot process or at any point once you're up and running? Random reboots are often caused by mechanical or thermal problems. Mechanical problems include little bits of conductor flopping around inside the laptop, vibrations caused by airplanes, tapping your foot on the floor or typing on the keyboard! Remember that the whole laptop is crammed into this narrow little box and the connectors are fairly fragile. You can eliminate flaky mechanical issues by trying a USB keyboard and mouse and not touching the laptop while operating. If that solves the problem, you know the reboots are due to vibration. For thermal problems, see the overheating flowchart. A random reboot is sometimes caused by a Windows operating system setting. This can be solved by going to System Properties
and selecting the Advanced tab, then the Settings tab under Startup and Recovery. Clear the checkmark under System Failure – Automatically Restart. It might solve the problem, or it might lead to a BSOD (Blue Screen of Death) error that helps diagnose the underlying cause, often RAM. Main battery installed? If not, try running with the battery installed, or try running your AC adapter though a UPS (Uninterruptable Power Supply). The problem may be with your electrical power grid, either brown-outs, surges, or poor regulation. Testing with the battery installed makes more sense than running out and buying a UPS, unless you have one available, but some laptop owners see extending battery life by storing it in ideal conditions when not traveling as half the fun of ownership. Ruled out software, virus? If you don't have an up-to-date malware protection suite installed, including anti-virus, antispyware, and anti-adware and a firewall, you haven't even begun to eliminate invasive software as the root of your problem. Installing all of this protective software after the fact will usually make you aware of a malware problem, but it may be too late to
cure it without extensive Google research on your part. The "good" software is designed to keep the "bad" software out. Getting rid of “bad software” once it's established on your laptop is more dicey.Software lock-ups can also occur because of data corruption or operating system registry confusion. While reinstalling the
operating system and starting over from scratch is the dodge of somebody who can't pinpoint the problem, it's often the only practical solution for the casual laptop user. You should run the standard operating system clean-up chores before giving up. Windows offers a number of hard drive maintenance tasks under System Tools. Random freeze? Is your laptop suffering from random lockups?
We're talking about lockups that you need to power off and on to clear. If you can CRTL-ALT-DEL your way out of a lock-up, in fact, if you can get any response with it at all, it's more likely a software conflict or incompatibility. Although the CPU, RAM and motherboard are all candidates for intermittent lock-ups, the hard drive and motherboard connections are also possible. Overheating is always suspect in random lockups. If you call tech support with these symptoms, they may recommend that you flash the BIOS to the latest version. The procedure is simple, you download the software from the manufacturer's website and the process is automatic when you run the program, but BEWARE. If you grab the wrong version of the BIOS off the web, if the manufacturer has made a mistake, if you can't quite determine which revision of a motherboard you have, or if the process gets interrupted in the middle by a power spike, etc, you can lose the motherboard. In other words, if the BIOS doesn't get completely installed or isn't correct, you can never boot the system again to fix it. But if you've concluded that the only option is buying a new motherboard or a new laptop, it's worth a try.
If the problem is with an external peripheral, the first step is to inspect and reseat the cable connecting the device to the laptop. If it’s a USB peripheral, the best test of both the device and the cable is to connect to another computer and see if it works. If it does, the problem is with the port hardware or the driver (see the keyboard, mouse and USB troubleshooting flowchart). If the port is physically loose or damaged, the repair requires resoldering or replacing on the motherboard.
Try a different USB port on the laptop and try reinstalling any driver software for the device.Forgets CMOS, loses time? If your laptop keeps forgetting the time and the date, or gives you an error message about CMOS settings every time you power on, your RTC (Real Time Clock) battery has probably died. This
battery is entirely distinct from the main battery that powers your laptop or the auxiliary battery some laptops featured for preserving memory in suspend states.It's a little battery mounted on the motherboard, usually a small disk like a wrist watch battery, and while they are widely available and inexpensive, gaining access to the motherboard to do the job can be a nightmare in some laptops. If you don't have a user’s manual with step by step instructions, search the web for a photograph illustrated guide for your exact model family. Boots w/o external connex? If the laptop boots up fine when you power up without any external connections, the problem is with the external device or with the software driver for it. External connections here include anything that isn’t part of the basic laptop, including: docking stations, port replicators, security devices, PC cards, USB devices, telephone and networking cables, an external video connection, speakers or a microphone. Don’t start trying to analyze why the device can’t affect boot in your case, just try without it.
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