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Bringing an laptop back By GREG SWAIN How could I bring myself chuck out a faulty laptop computer with a 1.8GHz AMD quad core processor, 4GB of RAM, a 578GB HDD and 1GB of dedicated video memory? The way out was to try to fix it, even though I’d never torn down a laptop before. What could possibly go wrong? M EMORY AND hard disk drive (HDD) problems aside, most laptops are simply discarded if they develop a hardware fault. By the time labour and parts costs are factored in, repairs are invariably uneconomic, especially if the machine is more than a few years old. Sometimes though, it is possible to repair a machine at reasonable cost if you’re prepared to have a go at it yourself. It’s not for the faint-hearted but there’s nothing like a challenge, especially if you’ve never stripped a laptop down before. Jan’s 4525s Jan’s HP ProBook 4525s laptop was only about three years old when it first began playing up. At unpredictable 28  Silicon Chip times, the machine would suddenly crash and display the blue screen of death, with the message that it had encountered a video driver fault. At other times, the entire screen would pixelate and “freeze”, so it was showing all the classic symptoms of a video system fault. Initially, the problem occurred only occasionally and was tolerated. However, as is the nature of this type of fault, it got progressively worse and so her son took the logical next step and reinstalled the video driver. It made no difference and eventually things deteriorated to the point where the machine was all but unusable. In fact, it sometimes even refused to boot. The HDD would start when the power button was pressed but that was as far as it would go, the screen remaining blank. At other times, it would boot normally but then crash shortly after. And sometimes it would work normally for a week or two before spitting the dummy again. It was all very frustrating and eventually Jan asked if I would take a look at the machine. Faulty system RAM? My initial reaction was that it might be a system RAM fault, since this RAM was probably also shared with the video system. If the RAM was faulty, that would explain why the computer sometimes refused to boot. And when it did boot, it was crashing when the faulty RAM was accessed by the video driver. siliconchip.com.au HP ProBook 4525s from the dead Well, that was the theory but the machine was about to shoot me down in flames. Jan brought the HP laptop around to my home one Saturday morning and we immediately set it up in the workshop. It turned out to be a wellspecced 64-bit Windows 7 machine with a 1.8GHz AMD Phenom II quad core processor, 4GB of system RAM and a 578GB HDD. It also boasted an AMD Radeon HD5000 graphics chip and, as I quickly discovered, 1GB of dedicated video memory. That meant that the system RAM wasn’t shared with the video after all and so my theory that faulty system RAM was the cause of the problem was already looking shaky. After all, why would it indicate a video problem when the machine blue-screened if the system RAM was at fault? Despite playing up like a secondhand chainsaw the night before, the laptop was now on its best behaviour and I was unable to directly observe the fault. And so, with no better ideas at this stage, I decided to try re-seating the system RAM to see if that would in fact cure the problem – no 2-minute task as it turned out. Laptops commonly hide their system RAM under a removable flap in the base. Not so on the HP 4525s; instead, it’s hidden under the keyboard and you have to partially dismantle the machine to get at it. Fortunately, I’d already googled “access RAM 4525s” and this had revealed a handy YouTube video showing how to do just that. It’s hardly rocket science. The first step is to remove the battery, after which you remove the battery compartment screws and two screws at the rear of the machine (one at either end). The top cover between the keysiliconchip.com.au board and the LCD is then lifted free. Undoing two more screws then allows the keyboard to be slid backwards (towards the LCD) and lifted clear. The keyboard is tethered to the motherboard by a flat ribbon cable but it’s easy to flip it over and place it to one side on top of the chassis. That done, I removed the single stick of RAM and carefully cleaned its contacts by rubbing them lightly with an eraser and a soft cloth. The RAM was then clipped back into place and the machine reassembled. It subsequently booted OK and we ran it through its paces. Unfortunately, the “cure” didn’t last long; the machine had only been on for about 10 minutes when the display suddenly pixelated and the operating system crashed. Back to square one, as they say. Jan needed to use the laptop for the time being and so she took it with her when she left. In the meantime, I gave her my Memtest86 CD to run on the machine. This gives the system RAM a real workout and she subsequently reported that despite running the test for several hours, the RAM came up squeaky-clean. A shiny, new machine A few more months then went by with the machine continuing to throw ever more frequent tantrums. In the end, Jan decided that she’d had enough and bought a very nice Asus laptop with a Core i5 processor and a full HD (1920 x 1080) display. It came with Windows 8 but we immediately upgraded it to Windows 10. The upgrade went without a hitch and the new Windows 10 install worked beautifully. Over the next week or so, Jan managed to get the HP 4525s working for long enough to copy all her personal A hot-air tool was initially used in an attempt to reflow the solder joints under the video chip but the problem was judging just how much heat to pump into it. Although not shown here, aluminium foil was used to shield the surrounding parts and the CPU was removed from its socket prior to applying heat. June 2016  29 This is the faulty motherboard after it had been removed from the chassis and stripped of its CPU, memory and heatsink/fan assembly. Replacing it with a secondhand board bought online was a real gamble. files onto an external HDD and then delete everything from the machine. It was then turned over to me to see if anything could be done to resurrect it. By now, my suspicions were that a video hardware fault on the motherboard was the real cause of the problem. Either one of the video RAM chips was faulty or, more likely, the video GPU (graphics processing unit) chip itself was the culprit. A bit of research on the internet quickly reinforced my suspicions. The video chip is a BGA (ball grid array) device, with the solder joints arranged in a grid underneath the chip itself. And with constant thermal cycling, it’s not unheard of for one or more of the solder joints to become intermittent and cause the very symptoms prevalent in this machine. I also came across some pretty crude “cures” for the problem. One involved wrapping the laptop in a blanket while it was running, so that it got stinking hot – hot enough, presumably, to cure the faulty joint. He’s got to be kidding; the chances of that working would be almost zero. In fact, you’d be more likely to damage other parts or start a fire! Another silly suggestion involved removing the motherboard and cooking it in an oven. Once again, he’s got to be kidding. Among the dross, there were also a couple of reasonably sensible ideas. One involved removing the mother30  Silicon Chip board and placing some cooking foil over it, with a square cut-out for the video GPU. A heat gun is then used to gently heat the chip, the aim being to heat it just enough to reflow the solder joints underneath (but avoid damaging it), while the foil acts as a heat-shield for the rest of the parts. Other variations on this involved using a specialised hot-air rework tool or even a professional re-flow station. I didn’t have access to the latter but I did have a hot-air rework tool so I decided to give it a go. Of course, judging just how much heat to pump into the graphics chip would be very much hit or miss but what was there to lose? The first step was figure out how to remove the motherboard. I won’t bore you with all the details but in summary, after removing the keyboard, you then remove the front cover with the touchpad, followed by the DVD drive, the HDD and the heatsink/fan assembly. The LCD is then removed by undoing the screws at the hinges and removing its attached cables at the motherboard end, after which you undo lots of hex-head screws and unclip the top plastic chassis frame. It’s then just a matter of undoing a couple of screws and freeing various cables before removing the motherboard from the chassis. Once the motherboard was out, I took the precaution of removing both the CPU and the RAM module and placing them in an anti-static bag. I then fired up the hot-air tool and gently warmed the graphics chip and surrounding area before really giving the graphics chip the treatment. It was impossible to know just how much to give it so I simply decided to “heat the hell out of it”. After all, it had to get hot enough for the solder joints under it to reflow, otherwise I would be wasting my time. The motherboard was then allowed to cool down, after which I patiently reassembled the computer, plugged it in and optimistically pressed the power button. Nothing! Absolutely <at>#$%&! nothing! Not even the power LED would turn on. It was bricked! There was only one way to fix this computer now and that was to replace the motherboard. Unfortunately, the cheapest (secondhand) board I could get from a supplier on AliExpress at the time was about $120.00. I discussed the matter with Jan and we both decided that it wasn’t worth it, especially as there were no ironclad guarantees that the transplant would be successful. I couldn’t throw it out Now I’m normally a pretty good “chucker” but somehow I just couldn’t bring myself to chuck this HP 4525s out. In the back of my mind, I kept thinking that maybe I could pick one up with a broken screen on eBay for next to nothing and transplant the motherboard. Or maybe the motherboards listed on AliExpress would come down in price. And so the machine sat in one corner of my workbench for several months while I kept my eyes open. Well, good things come to those who wait; the dollar rose, the prices drifted down and I eventually spotted one on AliExpress for $99.00 including delivery. I didn’t want to die wondering, so I ordered it. If the transplant didn’t work out, I would simply keep quiet and wear it. On the other hand, if the transplant was successful, I could boast about how clever I was! The replacement motherboard turn­ ed up a week later and I wasted no time stripping the machine down and swapping it into place. This also involved swapping over the CPU and RAM, the heatsink/fan assembly (and associated thermal pads), the audio input socket module and the WiFi module. siliconchip.com.au While I was at it, I also replaced the on-board lithium back-up battery. The original battery was now about five years old and I didn’t want to risk having to strip the machine down again in a few months time to change it. It was then just a matter of reassembling the machine. This took no more than about 40 minutes and when it was done, I slid the battery into place and hopefully pressed the power button. Nothing! Absolutely nothing! But wait – maybe the battery was flat; after all, Jan had mentioned that the battery didn’t last long in use and this one hadn’t been charged for several months. I connected the laptop’s power supply to the mains, plugged it into the machine and hit the power button again. This time, the power LED lit, the HDD whirred into life and the machine booted straight into Windows 7. And not an error message in sight! What’s more, it seemed perfectly stable and there were no tantrums, even after it had been running for several hours. During this time, I rebooted the machine several times to test it and it started each time without problems. I also entered in my WiFi set-up details, so that the machine had internet access but although everything worked, I wasn’t out of the woods yet. Hairy goat Where does the expression “it runs like a hairy goat” come from? I dunno but this laptop sure ran like one. It wasn’t surprising really, as it had been running like a hairy goat with the old motherboard. The problem was that a huge amount of software had been installed on it over the years by different family members and the operating system had become mangled. I tried running CCleaner and even ran CCleaner’s registry checker but it made little difference. The machine ran reliably but did so very slowly. A clean install of the operating system was clearly required and the best way to do that would be to first upgrade the operating system (OS) to Windows 10. Once the upgrade was in place and had been activated (this happens automatically if you have an internet connection), I could then reformat the HDD and do a clean Windows 10 install. As an aside, once a Windows 10 upgrade has been activated, Microsiliconchip.com.au Back in action: the HP 4525s is a reasonably quick machine that’s capable of running a range of applications. A fresh install of Windows 10 got it running at full throttle again. soft has the hardware details for your machine and you can then do a clean install without having to enter a product key. What’s more, Windows 10 will then automatically activate again once you’ve set up an internet connection. I had previously downloaded Windows 10 64-bit using Microsoft’s Media Creation Tool and had burnt it to a DVD. However, when I attempted to run this, it would only get about 23% of the way into upgrade before hanging. From past experience, I knew that out-of-date programs can stop the upgrade process, so I uninstalled as many applications as I could, cleaned up the registry and tried again. That did the trick – the Windows 10 upgrade now installed without a hitch. As expected, it still ran like a hairy goat and so, after checking that Windows 10 had activated (right-click “This PC” and click “Properties”), I booted from the Windows 10 DVD, reformatted the HDD and did a clean install. Once again, it all went without a hitch and I was looking at the new desktop after about 30 minutes. This utterly transformed the machine. Whereas before it had been a slug, it was now fast and responsive, in keeping with its specifications. The machine was back from the dead and it was working flawlessly with one exception. When I looked at the System Properties dialog, it indicated a missing HP AHCI driver. This driver parks the HDD’s heads when the machine is powered down and is vital in a portable device such as this. Retrieving and installing the indicated driver from HP’s website soon solved that problem. Jan prefers Google Chrome, so I then downloaded and installed that, along with Libre Office, Thunderbird (for email), CCleaner and VLC Media Player. I didn’t bother with a third-party anti-virus application. Windows 10 comes with Windows Defender built in and this offers basic protection. If you want something better, there are plenty of commercial and freeware anti-virus applications available. One of the leading freeware apps is “avast! Free Antivirus” but there are lots of others to choose from (see www. snapfiles.com/freeware/security/fwvirus.html) And that was it. The machine now serves as Jan’s “upstairs computer” and has proven to be completely reliable. And Windows 10 runs like it was made for the machine. So my gamble on the new motherboard paid off but was it all really worth it? Well, yes and no! Yes, because I really enjoyed the challenge of getting it going again and for an outlay of just $100 it’s a really good machine. And no, because if this had been a commercial exercise, it would have been completely uneconomic by the time six or seven hours of labour had been SC added onto the parts costs. June 2016  31