TideLog Archive for March, 2017

Today was another tinker day for me, and this time another YouView box from Humax. The T2100 replaced the ageing T1000 which was beset with issues, notably power supply issues with bad capacitors, as well as HDMI handshake problems, and just general reliability and use issues, such as recording failures (attributed to PSU issues, capacitors in the HDD 12v feed rail going dry or high ESR), freezing, and refusal to power on.

Most of the problems were down to the built in PSU which was fully onboard. The latest boxes, the T2100, T2110 and the newer 4K T4000 boxes are much smaller, and now use an external PSU brick, as well as smaller 2.5″ SATA HDD from a laptop, allowing Humax to shrink it massively. I have actually repaired a few in the past, mainly HDD failures due to 24/7 use and the Bathtub curve of HDD reliability being so unpredictable, but it’s the first time on TideLog for me to show you the wonderful neat innards, and much improved electronic design!

The only thing that’s needed is a Philips screwdriver. 4 screws on the bottom (self tappers into plastic, eurgh!) one of them under a warranty sticker (those things are just BEGGING to be peeled off!), remove the machine screw above the SCART socket, and off pops the cover!

I love the inside of these, I just love a neat circuit board, they’re a beautiful work of art in their own right. So, bottom left, the hard drive, which is a standard 2.5″ 500GB AV grade HDD, mine has a Western Digital AV-25 WD50000LUCT, which are designed for CCTV and PVR use, so are fine for 24/7 use. 4 screws underneath it hold it into place, the motherboard has to come out to remove it as it is actually screwed into the mainboard, not the chassis. One nice thing is that Humax have used rubber bumpers with the screws to shield it from knocks (not dropping it down stairs, as some of my repaired ones have been!) and also so that the screws are not in direct contact with the PCB.

To the bottom left of the HDD sits one of the box’s two USB ports, with the other being on the rear under the Ethernet port. To the right of the hard drive is what I assume to be the 12v regulator choke for the HDD, digitally controlled. To the right of that are the 4x1GB Samsung RAM chips, making a total of 4GB, which gives the box its stability power during marathon record 2-programmes-watch-another stints, to save it constantly caching everything to the HDD when rewinding, pausing or fast forwarding live TV, which, when recording two programmes and watching one would cause buffer issues, recordings would be glitched and the HDD under massive load.

Above the RAM is the CPU (possibly an ARM 2 or 4 core, I’ve never looked under the heatsink in one), under the big finned heatsink, which unlike the T1000, does not have a noisy fan cooling it down, it is fully passive, where the heat from it rises naturally out the top vents on the top cover. To the right of the RAM is the digitally controlled, beautifully intricate (shucks, I’m a true nerd!) 3 phase power regulation system. This splits up and regulates the 12v from the external brick, into all the voltages required by the components, and the CPU, which requires an ultra stable, clean and spike free supply. The HDD 12v regulator is fed from this system too.

The Broadcom Ethernet & dual-tuner control chips are to the top of these. This area also contains the white harness connector for the top cover switch block wiring which you can just see in the top of the image above. The switch block in the top cover is nothing special, just a PCB with switches soldered on 😉

There are still a few of the dodgy SamYoung (which brand does that sound like?) Chinese electrolytic capacitors in these units as there were with the old T1000 series. Luckily in the new T21xx series there are only 3 (the T1000 had 10), the rest are solid state, the ones in my unit are fine but we’ll have to see how long it is before they get binned for Japanese RubyCon YXF ones! There are two in the voltage regulation section, and one in the top left of the box below the DC IN switch/plug socket block that will likely be the first electrical repair I do 🙂

There’s not much info on the chips in these, I couldn’t make out the model numbers and a schematic is not in the wild. A future update to this article will be a teardown of the external brick, me using my magnifier (when I find it) to identify the chips and CPU, and exactly where that HDD regulator goes, if it is even for the HDD…

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