we bring back to life the “buried” CLEVO P970 service centers

Short description

The author couldn’t visit the Spanish flea market due to the Easter holidays and decided to write about repairing a CLEVO P970ED gaming laptop bought for 40 euros that was sold for parts. The laptop, equipped with an Intel Core i7-8750H processor, NVIDIA GeForce RTX 2060 8 GB GDDR5 graphics, 512 GB M.2 PCIe NVMe SSD, 1TB 7200 RPM HDD, 16 GB DDR4 RAM, and a 17.3-inch screen, had a short circuit on the board, resulting from the previous owner damaging the heads of attachment screws. The author studied and repaired the board, eliminating the short circuit and bringing the laptop back to life.

we bring back to life the “buried” CLEVO P970 service centers

Hello, Habre! I usually write about Spanish flea markets, but today is Catholic Easter, so the flea market is closed. Here, such mercadillos are by no means a spontaneous phenomenon, but are regulated by the municipality. Therefore, on holidays, when everything is closed, those flea markets do not work. It’s still a bit strange to me, but apparently this decision is somewhat justified.

So, since there is no flea market, and the mysterious “things” can’t be guessed either, I will tell you about yesterday’s repair of the CLEVO P970ED gaming laptop. I bought it for 40 euros. I bought more for parts than I estimated for the repair, because I thought that everything inside was very bad if the display was removed. And yes, my expectations were met – everything was bad. About how I brought back to life a laptop sold for spare parts, and without a circuit or a boardview (if you don’t know, I’ll tell you about it below) — under the cat. Let’s go!



What kind of laptop is this?


To be honest, I had never heard of CLEVO until I saw it on sale. Apparently, the same laptop is also sold under the name SAGER NP8961 – the same characteristics, board, etc., only the screen is not 17.3 inches, but 16.1.

The device is not bad, 2019, it has not had time to become obsolete. Here are its characteristics:

  • Intel Core i7-8750H processor.
  • Graphics: NVIDIA GeForce RTX 2060 8 GB GDDR5.
  • SSD: 512 GB M.2 PCIe NVMe.
  • HDD: 1TB 7200 RPM.
  • RAM: 16 GB DDR4.
  • Display: 17.3 inches, 1920 x 1080.
  • Camera: FHD.
  • Wireless: Intel Dual Band Wireless-AC 9560 M.2 AC Wireless LAN + Bluetooth
  • Audio: audio output is normal, plus S/PDIF.

Not the most productive machine, but it is quite capable of playing modern games. Of course, it was sold to me without disks, without RAM, and, as mentioned above, without a display. The case of the device is aluminum, with plastic elements, it looks good. Yes, and the RGB keyboard also looks good (more precisely, it looked when the laptop was working).

What was wrong with him?


Since I bought it for parts, I immediately connected it to the power supply. In general, this is a gross mistake, because if shorted, connecting the charger can make the problem worse. But, again, I collect the base of motherboards so that I have somewhere to solder spare parts, from SMD elements to processors and video cards. And I was not too worried about what was there and how, since I was sure that everything was bad with the laptop.

After connecting it from a laboratory power supply, I saw how the consumption increases to about 30 mA*h, then the LSHP clicks, the consumption drops and everything starts from the beginning. In this case, you can say with 99% that there is a short circuit on the board.

That’s how it turned out, I checked the first two mosfets (input keys, I talked about them in the last post). Everything was fine with them, but after the first one, instead of 19.5, something like 0.11V came out. Further along the circuit, a short circuit was detected. Generally speaking, if there is a short circuit in the primary power supply circuit, it may be that everything just burned out, for example, a ceramic capacitor somewhere near the input. And everything is bad with a breakdown in other power circuits, with burnout of the hub, multicontroller, video card, processor. Either all at once, or separately. But in any case, this is not done quickly and easily. And not cheap, yes.

How did you find the problem?


If there is a short circuit, then the easiest way to detect it is to apply a reduced voltage with a fixed current to the circuit with a short circuit – at first 1A, if there is no result, gradually increase it. Since it was not clear where the short was, I applied 1V to the circuit with a current limit of 2A. The consumption of about 1.5 A immediately went away.

If the board consumes so much, then something must be heating up, usually it is an element or chip that has failed (there are exceptions, of course). I check the heat using the thermal imager on the Blackview BV6600 Pro phone. There is a built-in Flir One thermal imaging module. It is far from the best thermal imager, but it is enough for my needs, although, of course, I would like something better. But I don’t want to spend 600-800 euros on a thermal imager.

Well, the thermal imager didn’t show anything. True, he showed heating in the place where the board is attached to the case, but there is usually always such evidence – there is a “glow” of a shiny metal surface, which the thermal imager shows how it is heating. So I didn’t pay attention to it. But nothing else warmed up, although with such consumption, even a large video chip should have warmed up or even heated up, if the problem was in it. But no, nothing like that.

This happens to solve the problem, I raised the voltage to 2V, after which the consumption increased to 2.2A. And again the thermal imager showed nothing but “light”. I decided to touch this place with my hand, and what was my surprise when I felt warmth in this very place of the board. The location itself looked like this, only a little more dusty. Unfortunately, I didn’t take a picture right away, because I didn’t think it would be possible to repair the board and write an article. But there are few differences from the photos.

As it turned out, the previous owner of the laptop damaged the heads of the screws that attach the board to the case. Probably, when replacing the keyboard, he twisted and unscrewed it many times, and with the wrong screwdriver, knocking off the cutting of the head. After that, the superbrain couldn’t think of anything better than to start sawing off the screw heads with something like a mini milling cutter. It turned out only worse – it was not possible to cut, the cogs were permanently damaged, plus the board was also caught. Without a microscope, you can’t see anything in particular, the cut was small, if you just look – well, a deep scratch.

What was the problem and how did I solve it?


First, a little about boards – modern boards for laptops, smartphones and many other devices are multi-layered. What you see above and below the board is only part of the contact tracks. Many go inside the textolite, and there may be more than one or two layers. In this board, I counted five layers, if you run ahead.

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And, as far as I understood, by cutting a bit into the board, our superbrain unknowingly connected the layer of the primary 19.5V power circuit with the contact of the secondary 5.5V power circuit. When connecting this laptop, the owner clearly had a good blow (with sparks, smoke, stench, everything as it should be), and the entire laptop failed.

Usually, neither official service centers nor other workshops take care of such breakdowns – the amount of work can be too unpredictable. True, there are kulibins, I once saw a video on YouTube of a well-known master (known, of course, among a narrow circle of repairmen), who, having encountered a board that burned out, sawed off a piece, then inserted a similar piece from another board. There, the work was just jewelry, and for its implementation you need to be a professional of the highest class.

But there are few such masters, and far from all professionals will agree to mess with textolite that has burned out, simply because it takes a lot of time for this, and the client who came to the center wants to pay little money. In short, it is simply economically unprofitable.

Well, I didn’t have much to lose, so I started to repair it. It consisted in studying the place of damage, with elimination of the short circuit. I did not hope for anything, because I am very far from real professionals. But trying isn’t torture, is it? It is necessary to learn from something. I have already successfully eliminated a couple of strong losses in the past, so I had some experience.

For the repair, I used a micro-engraver that works on batteries. It’s about the size of a ballpoint pen, making it very comfortable to hold. There are several interchangeable nozzles, I used the thinnest one at the very beginning and then the thicker one. The engraver is in the photo below.

The work to eliminate burns consists in carefully removing the damaged layers of the board. To perform such operations, it is better to first practice on non-working boards, and then proceed to those “corpses” that you are going to revive. As it turned out, a fairly decent area of ​​the “between the dress” burned out, it was necessary to dig thoroughly until, after measurements, it turned out that the short circuit was gone.

What then?


I checked the resistances on the main chokes of the power supply circuits, and nothing strange caught my eye – the processor seemed to be alive, the graphics adapter too (this is determined by the resistance in their power supply circuits). Well, it’s time to connect the board to the power supply. That’s what I did, after which I saw that the consumption increased to 11 mAh and remained so. Plus, the LED that is responsible for indicating the operating mode of the board lit up.

Deciding that the problem was solved, I pressed the power button, the LED changed from orange to green and… nothing happened. Actually, I didn’t have much hope that the laptop would “start up” right away, but it was still there. Ah, yes, and the laptop began to charge – consumption after connecting the battery increased to 2.8A, plus the battery indicator LED flashed.

But that’s all, the board didn’t turn on. The worst thing was that I didn’t have either a board diagram or a boardview (this is such an interactive drawing of the board with the names of elements, the connection between them, etc.). I understood that this is a rare board, and on the Internet I found only a scheme that was sold for 5 euros. To be honest, I lost hope for a successful repair, I even became upset. It’s still a pleasure to fumble around in a burned-out circuit board even with a schematic.

I thought that I would sell the laptop for parts, except for the fee, which I would keep for the parts. But before taking it all apart, I decided to once again inspect the place of the burn, where there was no longer a short circuit. I thought that some important contact might be damaged here, either because of a burnout or because of my work with the engraver. Under the microscope, I counted the number of layers and began to “ring” the opposite sides – I thought that if the resistance between similar layers is zero, then the contact is not broken in this place. So it turned out. But then, looking closely, I saw a thin track that was torn exactly at the point of the cut. I didn’t take a picture of this place right away. But there is already a photo after the repair of the path – for understanding, the wire is taken from the wire for charging the iPhone, it is a very thin vein, it is four times thinner than a human hair.

Before soldering it, I filled the layers below with a special protective mask – this mask then hardens under UV rays and becomes solid.

Well, after the manipulations, I connected the laptop, pressed the button, and … this time the consumption began to increase, to about 700 mA * h without RAM. After inserting the RAM, I saw the consumption increase to 2.5A, which indicated that the board is most likely working. When I connected it to HDMI, I got no picture, although usually boards with the display turned off output the picture to an external source.

Two options remained – either something else is broken, or simply the board does not display the BIOS interface on an external monitor. Decided to throw up the display. I didn’t have a 17.3-inch screen, so for testing I took a screen with the same pinout (40 pins on the left) from another gaming laptop from ASUS. Of course, I checked that the characteristics, except for the size, were approximately equal. Well, after a while, after 3-4 power-on/off cycles (gaming laptop boards usually don’t turn on immediately), I got an image on the screen.

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We can say that the repair was successful! The OS installation, graphics, sound, communication and other checks are still to be done. But the main task – to return the laptop to the world of living electronic devices, I accomplished. And yes, the repair took about 3 hours, with the fuss of removing broken cogs, diagnostics and finding a suitable screen.

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