Category: Hardware news

Zebra server maintenance

21:40 EEST: Zebra server will be shut down for planned maintenance. Expected downtime is up to 2 hours.
Very sorry for inconvenience caused.

Zebra server down.

Zebra server is down due to a power failure on site.

Will update when it’s back online.

UPD 3:00 AM EEST: back up.

Zebra server downtime

Zebra is down due to power maintenance on the site. Will update when everything comes back online.

BTW, sorry for lack of posts. This site is not abandoned. The USB modem Linux box howto is still on my TODO list.

Zebra maintenance

Zebra server was shut down for routine maintenance. It will be back online shortly.

Lithium cell salvaging

This isn’t my normal topic, but it’s something I’ve been doing for quite a while.

  1. The story

I’ve probably mentioned before that I do computer servicing as a hobby. Nowadays, I have very few customers (my guess is due to a small repair shop opening locally some time ago – people for some reason seem to trust companies more than individuals, no matter how much experience or what reputation you have in your field of work).

But in the past, I used to get a lot of systems for servicing. Among those systems were many laptops.

Unfortunately, while desktop towers can usually always be serviced in one way or another, some laptops that people brought me were beyond economical repair. Problems such as fried GPUs, bad tantalum capacitors, etc. were common back in the day. My offer in these cases usually boiled down to just salvaging data from computer’s storage and sending the computer to e-waste. Often, after salvaging data, owners would just leave those dead computers to me for spare parts.

And many of those computers still had their batteries installed.

2. Cell salvaging

Older laptop batteries were usually made from a bunch of cylindrical 18650 Lithium-ion cells connected in various series-pair configurations (nowadays, they mostly use Li-Po cells instead, altough 18650s are still common). Usual configurations are 4×2, 3×2 and 2×2, depending on laptop’s power requirements. Cell capacities also varied, older systems had 2000-2200mah cell, while newer ones had bigger 2800mah cells. Despite the battery itself usually being disabled by it’s electronics, those cells usually still had some voltage and would happily take a charge. Surprisingly, many even charged to their full rated capacity (there’s a catch – read further).

Sanyo/Panasonic cells were some of the best performers (I have several working cells from early 2000s !), while Samsung cells often had degraded capacity. LG were the worst performers, usually with really high internal resistances and somewhat degraded capacity. But even good cells from these laptop batteries did show signs of age. They often had increased internal resistance and degraded capacity at higher loads. But nevertheless, there are still uses for them as not all devices need high currents to operate.

3. My uses for salvaged cells

My most common use for these cells is building power banks. But not your usual power banks for charging gadgets but those which can produce higher voltages. Voltages like 9V, 12V, 12V, etc. These can be used to power various low-power electronic devices which are normally powered by wall-wart style power supplies (e.g. routers, switches, 3.5″ external drive boxes, amplified audio speakers, etc). These banks are useful for using those normally mains-powered devices on the go or powering them during power outages (which aren’t that uncommon in my part of the world during thunderstorms in summer months).

To build those power banks, I use DIY boxes from AliExpress branded “Aili”. These used to be dirt cheap (few EUR a piece) but prices seem to have risen nowadays. 6 and 4-cell versions are available. These boxes do have USB outputs which can work for charging your phone, but they are usually only 2 amps and are inefficient due to those cheap boxes relying on linear instead of switch-mode DC-DC step-down converters for their 5V USB outputs. Unlike your run-of-the-mill power bank, those boxes are optimized for higher voltage applications, not gadget charging.

6-cell version can output voltages up to 20V (5V, 9V, 12V, 15V, 19V and 20V) at 3A, while 4-cell box does up to 15V at 1.5A (lower voltages at up to 2A). One downside of the 6-cell version is that it requires at least a 15V power supply to charge cells with it’s built-in charger. 4-cell unit uses micro USB instead.

Those “Aili” boxes use standard barrel jacks for higher voltage outputs, with male-male power cables included with the box.

Nowadays, with the arrival of USB-C, there are DIY power bank boxes available on AliExpress which do support USB-C PD. Unfortunately, most of these boxes seem to top-out at 22.5W (even ones with 16 or 24 cells), my guess is because the great majority of them use a all-parallel configuration instead of series pairs (like the “Aili” boxes). Also, they rarely have anything besides 5V output.

I did find one vendor which sells custom-designed powerbank boxes with USB-C PD 60W or even 100W output capability. Interestingly, they do come in clear acrylic cases and can even be bought partially assembled as kits. They aren’t cheap but I shall order one anyway to try out as they seem to be well built.

4. There’s more…

Although they uncommon, factory-made powerbanks based on 18650 cells do exist. I just found that out after opening my beefy old 65W 20800 mAh USB-C powerbank (which had it’s magic smoke escape while charging) to salvage it’s lithium cells. Instead of the usual stack of Li-Po cells, I found a pack of 8x 2600 mAh 18650 cells in a 4×2 series pairs configuration. Interestingly, the battery pack has it’s own separate PCB, similar to those found in laptop batteries. It’s output is directly connected to the main power-bank PCB. Even though the main PCB was dead, the pack itself was still good, reading 15.6V.

Since 18650 Li-Ion cells have higher cycle life than Li-Po, power banks based on 18650s should last longer. Their major downside is their bigger size due to them using cylindrical cells. My guess is that’s why they are uncommon nowadays.

Cylindrical lithium cells (18650 and 21700) are also common in power tool batteries and some household electronics, like portable vacuum cleaners.

That will be all. My congratulations if you made this far 🙂

Comments are welcome. I’m not really much of an expert when it comes to lithium batteries. Do correct me if I made any mistakes in this post. And excuse me for my language imperfections.

New main PC

I’ve decided to build myself a new PC for Christmas, to replace my aging i7 2600k.
lso got a new 4K monitor along with it.
CPU: i7-9700k (cooled by Corsair H100i Pro)
RAM: 32 GB DDR4 3000 (4x 8 GB Corsair Vengeance LPX)
MB: Gigabyte Z390 Aorus Pro
GPU: GeForce 2080 Ti (Palit 2080 Ti GamingPro, TU102-300A chip)

Samsung Evo 960 500 GB NVME SSD (from my old build)
Crucial MX500 1 TB SATA SSD
OCZ Vertex 3 120 GB SATA SSD (old beast, MLC based)
2x 2TB HDDs (Samsung HD204UI and Seagate ST2000DL003) in RAID 0

Case: Corsair 460X
PSU: Corsair TX850 V2 (old beast, but still going strong)
Monitor: LG 27UK600 4K @ 60 Hz
OS: Windows 10 Pro / Ubuntu 18.04 dual-boot

I plan to do some new Android x86 builds with this rig in near future. And of course, some 4K gaming.

— overclocking —

Tried doing some overclocking on the CPU and GPU, and I can already say that I likely did not win the highest prize in the silicon lottery. The 2080 Ti can handle +160 Core and +500 memory just fine but going beyond +160 core results in random GPU lockups (the more you push, the more unstable it gets) even though the temperature is way below 80 C. This is strange for what is supposed to be a higher-binned version of the Turing chip. The card is supposedly based on a reference schematic but with non-reference components. This suggests any BIOS from a reference card should work. And reference BIOSes do work (at least, they do not brick the card), but none I have tried so far are stable, even BIOS from OC version of the same Palit card.

As for the i7, I can’t find how to properly OC it. For my old 2600k, simply finding the right vCore voltage was enough, but squeezing out more power out of these modern chips requires much more research than just finding the right vCore. I did get 5 GHz to work, but with some random crashes every now and then. Right now, I’ve decided to call it quits and left the CPU at stock settings (I did leave the 95 W TDP limit disabled though).

Zebra server maintenance

Zebra server ( offline for maintenance.
Sorry for incovenience.
Will update this post when maintenance is complete.

UPDATE 9.00 PM EET: Server back online.

New server online

I’ve recently upgraded my home connection to Gigabit fiber (1000 mbps down /500 mbps up) and, since I now have 500 mbps of upload bandwidth, I’ve set up a new server.

Since this server has faster upstream connection that that of Raspis, I’ll probably move some of my stuff from Raspis to this new server in near future.

Server specs for those interested:
CPU: Intel G4600
NIC: 3x Realtek Gigabit NICs (separate NICs for Router, Internet and IPTV)
Storage: 6 HDDs, approx 3.33 TB of storage.

EDIT: Speedtest (that’s with IPTV and some other stuff running).

Again, I forgot to make a new year post… Dammit.

Let’s start with some good news first. I bought myself a Raspberry Pi 3  for Christmas.

Bought it without a case, because I wanted to buy a Kodi edition FLIRC case for it.

Now, the fun part. There are 2 suppliers of this case: The Pi Hut in the UK and FLIRC (the manufacturer) in the US.

I’m in the EU. Guess which supplier I’ve ordered from ? No, you guessed it wrong. I had to order it FROM THE USA, because the Pi Hut, despite all my attempts to convince them, refused to ship the case to my country, telling me some bull**it about too many lost parcels. Yeah, right… I’ve ordered from the UK dozens of times and had only one or two lost orders. If the US supplier CAN ship to the EU why can’t they ?

I had to wait 3 weeks for the case to arrive from the US (instead of just a week, had I ordered the case from the UK supplier). Had to run my Pi barebones during that time.

That was the good news.


The bad news is that the primary server is down again. But this time it seems it’s the server’s ISP (yes, an entire ISP) went offline, because their homepage and corporate page are both down too, not even DNS works. WTF ?

Will update on this.
EDIT: it seems everything is back online now. Downtime lasted about an hour.

February update

Another long story. Again, to avoid mixing up things, it consists of two parts.

  • Part one: A really cooked laptop

My cousin gave me his dead laptop to see if I can resurrect it. The system is an old but still decent Toshiba Tecra S-11 equipped with a dual core i7-640M, 8GB of RAM, Nvidia Quadro NVS 2100M video card and a 15.6 widescreen display with 1600 x 900 resolution. There was no hard drive or DVD.

The system was totally dead, not even a single LED worked. I suspected a bad mainboard. I’ve tried searching eBay and other places for a replacement board but found nothing. So I’ve decided to bring the laptop to a local computer shop (they have a service center as well) to see if they could do anything. The shop confirmed my suspicions: the system’s power IC was totally fried.

They did manage get a new (well, refurbished) board from a local Toshiba service center. I paid 100 € for a new board and re-assembly.

Since the system had no hard disk or DVD drive, I’ve also bought an 120GB SSD and a DVD burner for about 72 €.

Before installing the SSD and the DVD burner, I wanted to do some basic tests to see if the system works. So I’ve plugged in my boot flash drive and tried to boot my custom Windows PE recovery environment. It failed to boot with a BSOD. Then I’ve tried a Linux Live DVD. It also failed to boot with a kernel panic caused by a MCE (machine check exception).

I could only get anything to boot by disabling the second CPU core or limiting the OS CPU count to 3. That really smelled like a CPU problem to me…

I know my cousin did some heavy compiling on that system and it was overheating badly (the cooling system is very poor) but to damage a CPU ? How hard do you have to torture a system to not only fry the mainboard but to damage a CPU as well ?

Indeed my suspicions were confirmed. After I’ve replaced the original i7 with a slightly weaker i5-560M (which I got for 35 €), all MCE errors disappeared.

So, after paying 207 € and spending a few hours on dis-assembly and re-assembly, I had a fully functional system. Yeah, I know I paid too much, but whatever…

The complete specs:

Model: Toshiba Tecra S11-14P

CPU: Core i5-560M (Dual core with HT)

RAM: 8GB DDR 1066 (2x 4GB)

GPU: Nvidia Quadro NVS 2100M

Storage: 120 GB SanDisk Ultra 2 SSD


Wifi: Intel AGN 6200

Display: 15.6″ 1600 x 900


  • Part Two: bad luck with T100TA

I’ve smashed my T100TA AGAIN. The damn thing fell down while it was in the bag. The glass was totally smashed and unusable, way worse than my first time.

The screen on that tablet is extremely fragile. I’ve dropped my old TF300T countless times without any damage and only managed to crack the screen by accidentally pushing it against the phone charger while the tablet was in the bag.

But the glass on T100TA’s screen is nothing like that of TF300T: it’s thin. Really thin. Seems like you could crack it by just pushing your finger harder against the screen.

I haven’t yet decided whether I will replace the screen. I can get an used T100TA for about the same price as a new screen. But then again, I’m not sure I even want another T100TA.

I will try bringing the tablet to a local computer shop to see if they can repair the screen for less that what Asus service charges. If they can’t, I will probably just get a new tablet.

Will update.



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