Just a quick teardown this month! This is an industrial RS-232/RS-485 to Ethernet serial converter.Not much to say about the outside of the unit, there’s the DB-9 connector for the 232 interface, and Phoenix connector blocks for the 422/485 interface. The main power input, and the Ethernet jack are on the other side.
PCB
Under the hood, there’s a pretty densely populated board. The brains of the operation is a IP210T Serial to Ethernet SoC with A/D Converter. This is an 8051 based core, wuth 10/100 MAC. No flash memory here either, only 64KB of OTP EPROM. On the left there’s a few bus transceivers to interface the serial ports, along with some glue logic. At the top we have the Ethernet magnetics, configuration EEPROM for the SoC & a trio of indicator LEDs.
Power supplies are dealt with via an LM2576-3.3 DC-DC buck converter, providing the main 3.3v rail for the logic.
Being in technology for a long time, I have seen my fair share of disk failures. However I have never seen a single instance where SMART has issued a sufficient warning to backup any data on a failing disk. The following is an example of this in action.
Toshiba MQ01ABD050
Here is a 2.5″ Toshiba MQ01ABD050 500GB disk drive. This unit was made in 2014, but has a very low hour count of ~8 months, with only ~5 months of the heads being loaded onto the platters, since it has been used to store offline files. This disk was working perfectly the last time it was plugged in a few weeks ago, but today within seconds of starting to transfer data, it began slowing down, then stopped entirely. A quick look at the SMART stats showed over 4000 reallocated sectors, so a full scan was initiated.
SMART Test Failure
After the couple of hours an extended test takes, the firmware managed to find a total of 16,376 bad sectors, of which 10K+ were still pending reallocation. Just after the test finished, the disk began making the usual clicking sound of the head actuator losing lock on the servo tracks. Yet SMART was still insisting that the disk was OK! In total about 3 hours between first power up & the disk failing entirely. This is possibly the most sudden failure of a disk I’ve seen so far, but SMART didn’t even twig from the huge number of sector reallocations that something was amiss. I don’t believe the platters are at fault here, it’s most likely to be either a head fault or preamp failure, as I don’t think platters can catastrophically fail this quickly. I expected SMART to at least flag that the drive was in a bad state once it’s self-test completed, but nope.
Internals
After pulling the lid on this disk, to see if there’s any evidence of a head crashing into a platter, there’s nothing – at least on a macroscopic scale, the single platter is pristine. I’ve seen disks crash to the point where the coating has been scrubbed from the platters so thoroughly that they’ve been returned to the glass discs they started off as, with the enclosure packed full of fine black powder that used to be data layer, but there’s no indication of mechanical failure here. Electronic failure is looking very likely.
Clearly, relying on SMART to alert when a disk is about to take a dive is an unwise idea, replacing drives after a set period is much better insurance if they are used for critical applications. Of course, current backups is always a good idea, no matter the age of drive.
I was recently given a pretty nice LED backlit 1080p LG monitor, with the instruction that it wouldn’t power on correctly. The monitor would power on as far as the standby light, but when fully powered on, would flash the backlight momentarily then shut down. A power supply issue was immediately suspected.
LCD Logic Board
I popped the covers off the monitor itself first, thinking that it was an electrolytic gone bad in the backlight DC-DC converter. Not to mention the fact that cracking into a wall-wart type of PSU is only occasionally possible without the use of anger & large hammers. (Cracking the glue with the handle of a screwdriver doesn’t work so well when the factory went a bit nuts with the glue/ultrasonic welder). As can be seen in the photo, there’s not much inside these monitors, the logic is a single-chip solution, the rest of the PCB is dedicated to supplying the power rails for the various circuits. On the left is the power input & the DC-DC converter for the backlight, along with the DC-DC converter supplying the logic circuits. None of the capacitors here are damaged, everything looks good.
I then measured the output of the PSU, which under no load was the correct 19v DC. However applying any load caused the output voltage to drop like a proverbial brick. Applying a full load of 1.3A saw the output voltage drop so severely that the PSU tripped on it’s UVLO.
200mA Load
At 200mA of load the factory PSU is already dropping to 18v, with a 5.3kHz switching frequency appearing.
500mA Load
At higher load the frequency increases to 11.5kHz & the output voltage has dropped to 11.86v!
750mA Load
750mA was as high as I could make the supply go without it tripping itself out – the UVLO circuit trips at 9v. 12.6kHz is now riding on the severely low DC at this point.
PSU Ratings
The power supply is supposed to be rated at 1.3A at 19v, however with this fault it’s getting nowhere near that. The LG brand is on this PSU but it’s contracted out to Shenzen Honor Electric Co. Ltd.
Output Electrolytic
Here’s the problem with this PSU. The output electrolytic has ballooned. I don’t have an ESR tester, but this cap has gone way past it’s sell-by date. It’s position right next to the heatsink with the output rectifier diodes has probably cooked it. The PSU isn’t that badly built for a Chinese one – there’s plenty of creepage distance on the PCB & even a couple of isolation slots.
Magnetic tape is the medium of choice for my offline backups & archives, as it’s got an amazing level of durability when in storage. (LTO Has a 30 year archival rating).
For the smaller stuff, like backing up the web server this very site runs on, another format seemed to suit better. Above is a HP DDS4 tape drive, which will store up to 40GB on a cassette compressed.
I picked this format since I already had some tapes, so it made sense.
Data Plate
Here’s the info for those who want to know. It’s an older generation drive, mainly since the current generation of tape backup drives are hideously expensive, while the older ones are cheap & plentiful. Unfortunately the older generation of drives are all parallel SCSI, which can be a expensive & awkward to set up. Luckily I already have other parallel SCSI devices, so the support infrastructure for this drive was already in place.
Option Switches
On the bottom of the drive is a bank of DIP switches, according to the manual these are for setting the drive for various flavours of UNIX operating systems. However it doesn’t go into what they actually change.
Controller PCB
The bottom of the drive has the control PCB. The large IC on the left is the SCSI interface, I’ve seen this exact same chip on other SCSI tape drives. Centre is a SoC, like so many of these, not much information available.
Drive Frame
Removing the board doesn’t reveal much else, just the bottom of the frame with the tape spool motors on the right, capstan motor bottom centre. The bottom of the head drum motor is just peeping through the plastic top centre.
Head Drum
Here’s the head drum itself. These drives use a helical-scan flying head system, like old VHS tape decks. The top of the capstan motor is on the bottom right.
Cleaning Brush
Hidden just under the tape transport frame is the head cleaning brush. I’m not sure exactly what this is made of, but it seems to be plastic.
Loading Motor
A single small DC motor with a worm drive handles all tape loading tasks. The PCB to the bottom left of the motor holds several break-beam sensors that tell the drive what position the transport is in.
Tape Transport Mech
Here’s the overall tape transport. The PCB on top of the head drum is a novel idea: it’s sole purpose in life is to act as a substrate for solder blobs, used for balancing. As this drum spins at 11,400RPM when a DDS4 tape is in the drive, any slight imbalance would cause destructive vibration.
Tape Transport
Here’s the drive active & writing a tape. (A daily backup of this web server actually). The green head cleaning brush can be better seen here. The drive constantly reads back what it writes to the tape, and if it detects an error, applies this brush momentarily to the drum to clean any shed oxide off the heads. The tape itself is threaded over all the guides, around the drum, then through the capstan & pinch roller.
Here’s another retired piece of tech that we used to route media from the NAS to the main TV. It was retired since it’s inability to support XBMC/Kodi & having some crashing issues.
Main PCB
After attacking the case with the screwdriver (Torx in this case), the main board comes out. The CPU in this looks *very* familiar, being a PoP device. There are unpopulated places for an ethernet interface & USB port here.
Flash & CPU
After a little digging is turns out the CPU in this device is a BCM2835, with 256MB of RAM stacked on top. It’s a Raspberry Pi! Even the unpopulated part for Ethernet is the same SMSC LAN9512!
There’s 32MB of Flash for the software below the CPU.
On the far right of the board is a Broadcom BCM59002IML Mobile Power Management IC.
WiFi Chipset
On the bottom of the PCB is the WiFi chipset, a Broadcom BCM4336, this most likely communicates with the CPU via SDIO. There’s also a section below for a Bluetooth chipset.
Here’s a quick look at one of the now surplus cards from my old networking system, a MiniPCI Wireless interface card.
Card Overview
This is an older generation card, one of the first with Wireless N support on 2.4GHz.
PCI Chipset
Network PHY & firmware EEPROM. Power supply stuff is over to the left.
RF Transceiver
Inside the shield is the RF Transceiver IC & it’s associated RF power amplifier ICs for each antenna. These power amplifiers are LX5511 types from Microsemi, with a maximum power output of +26dBm.
The multimode dimming/flashing modes on Chinese torches have irritated me for a while. If I buy a torch, it’s to illuminate something I’m doing, not to test if people around me have photosensitive epilepsy.
Looking at the PCB in the LED module of the torch, a couple of components are evident:
LED Driver PCB
There’s not much to this driver, it’s simply resistive for LED protection (the 4 resistors in a row at the bottom of the board).
The components at the top are the multimode circuitry. The SOT-23 IC on the left is a CX2809 LED Driver, with several modes. The SOT-23 on the right is a MOSFET, for switching the actual LED itself. I couldn’t find a datasheet for the IC itself, but I did find a schematic that seems to match up with what’s on the board.
Schematic
Here’s that schematic, the only thing that needs to be done to convert the torch to single mode ON/OFF at full brightness, is to bridge out that FET.
Components Desoldered
To help save the extra few mA the IC & associated circuitry will draw from the battery, I have removed all of the components involved in the multimode control. This leaves just the current limiting resistors for the LED itself.
Jumper Link
The final part above, is to install a small link across the Drain & Source pads of the FET. Now the switch controls the LED directly with no silly electronics in between. A proper torch at last.
Since I have a fair few 750GB disks sat doing nothing, I figured I’d get some USB3 caddies for them. Back when USB -> IDE caddies appeared, they were hideously expensive. Not so much these days!
USB HDD
For £6 on eBay, you get a basic plastic box with the required bridge circuitry.
USB – SATA Bridge
Here’s the PCB – a very basic affair, with only 2 ICs. The large QFN IC on the left is the USB-SATA bridge. It’s a JMicron JMS567. Unfortunately JMicron are rather secretive about their bridge chips & I can’t find much information about it, nor a datasheet.
PCB Reverse
Here’s the other side of the bridge PCB – not much on here, the activity indicator LED is a bit of a bodge job, but it’s functional. The IC on the right is a Pm25LD512 512Kbit SPI EEPROM. This is used to store things like the USB device & vendor IDs, device name, type, etc. Here’s what dmesg spits out when the disk is connected on my standard Linux system:
[snippet id=”1769″]
Here’s some speed benchmarks:
USB2 Benchmark
First attached to a USB2 port, above
USB3 Benchmark
And finally attached to a USB3 port, above
Tests were done with a 320GB 5400RPM Samsung HM321HI drive, direct into the root hub, for the shortest possible signal length.
I have recently begun to create an archive of all my personal data, and since LTO2 tape drives offer significant capacity (200GB/400GB) per tape, longevity is very high (up to 30 years in archive), & relatively low cost, this is the technology I’ve chosen to use for my long term archiving needs.
Unfortunately, this drive was DOA, due to being dropped in shipping. This drop broke the SCSI LVD connector on the back of the unit, & bent the frame, as can be seen below.
Broken SCSI
As this drive is unusable, it made for a good teardown candidate.
Cover Removed
Here the top cover of the drive has been removed, showing the top of the main logic PCB. The large silver IC in the top corner is the main CPU for the drive. It’s a custom part, but it does have an ARM core.
The two Hitachi ICs are the R/W head interface chipset, while the smaller LSI IC is the SCSI controller.
The tape transport & loading mech can be seen in the lower half of the picture.
Main Logic
Close up of the main logic.
Tape Spool
Here the main logic PCB has been removed, showing the tape take up spool. The data cartridges have only one spool to make the size smaller. When the tape is loaded, the drive grabs onto the leader pin at the end of the tape & feeds it onto this spool.
The head assembly is just above the spool.
Bottom Plate Removed
Bottom of the drive with the cover plate removed. Here the spindle drive motors are visible, both brushless 3-Phase units. Both of these motors are driven by a single controller IC on the other side of the lower logic PCB.
Head Drive Motor
The head is moved up & down the face of the tape by this stepper motor for coarse control, while fine control is provided by a voice coil assembly buried inside the head mount.
Tape Head Assembly
The face of the tape R/W head. This unit contains 2 sets of 8 heads, one of which writes to the tape, the other then reads the written data back right after to verify integrity.
Cartridge Load Motor
The tape cartridge loading motor. I originally thought that this was a standard brushed motor, but it has a ribbon cable emerging, this must be some sort of brushless arrangement.
A replacement drive is on the way, I shall be documenting some more of my archiving efforts & system setup once that unit arrives.
There have been quite a few updates to the hosting solution for this site, which is hosted locally in my house, from the above setup, in a small comms rack, to a new 22U half rack, with some hardware upgrades to come.
Core Switch Disconnected
Core switch here has been removed, with the rest of the core network equipment. The site was kept online by a direct connection into the gateway to the intertubes.
Switching Gear Installed
New 22U rack, with the core switch, FC switch & management & monitoring server installed.
Router Going In
As I had no rack rails to start with, the servers were placed on the top of the rack to start off, here is the Dell PowerEdge 860 pfSense core router installed, with the initial switch wiring to get the internal core network back online. This machine load balances two connections for an aggregated bandwidth of 140MB/s downstream & 15MB/s upstream.
The tower server behind is the NAS unit that runs the backups of the main & auxiliary webservers.
Almost Done
Still with no rack kits, all the servers are placed on top of the rack, before final installation. This allows running of the network before the rest of the equipment was installed.
The main server & aux server are HP ProLiant DL380 G3 servers, with redundant network connections.
Still to arrive are the final rack kits for the servers & a set of HP BL20p Blade servers, which will be running the sites in the future.
Here is a SCSI U320 Ultrastar drive with a slight issue: the magnetic coating has been scrubbed off the substrate. I’ve never seen this happen to any other drive before.
The inside of the drive is coated with the resulting dust created from this rather epic failure mode.
This will be the record of building a new Media PC, above you can see the finished system.
It’s Mini-ITX based, with on-board HDMI output, specifically to run XBMC via Fedora for media purposes.
CiC MTX001B Mini-ITX Case
This is the case that is being used, around the size of a Shuttle PC. It has a single 3.5″ & 5 1/4″ bay, for a HDD & ODD, front panel USB, Firewire & Audio.
Intel BLKDH57JG Mini-ITX Motherboard
Motherboard to fit the case. Supports Intel Core i5 series CPUs, with up to 8GB of DDR3 RAM.
Other features are on-board full surround audio, HDMI, eSATA, & a single 16x PCIe slot.
Corsair 4GB DDR3 DIMMs
Matching memory for the motherboard, a pair of 4GB DDR3 units.
Akasa K25 Low Profile CPU Cooler
Having never been impressed by bundled coolers with CPUs, here is an aftermarket low-profile unit, with solid copper core for enhanced cooling. This cooler is specially designed for Mini-ITX uses.
Intel Core i5 650 Dual Core 3.2GHz CPU
The brains of the operation, Core i5 650 CPU, should handle HD video well.
Above is the image projected from the Pi, on the default login screen. Distance from the projector is approx 10 feet.
Projector
State of the art projector mount, fashioned from several cable ties. HDMI cable is plugged into the right hand side of the projector.
Unfortunately the projector cannot handle audio on the HDMI connector, the 3.5mm headphone jack on the projector is for splitting audio out of the iDevice connection only, and does not make the HDMI audio stream available.
Pi
The Raspberry Pi, hosting a USB keyboard, & USB powered speakers. Running the standard Debian release, on a 16GB card, with omxplayer installed for media functions.
Here is a 2Gbit Fibre Channel transceiver from Cisco Systems in SFP module format.
Shield Removed
Here the shield has been removed from the bottom of the module (it just clips off). The bottom of the PCB can be seen, with the copper interface on the left & the rubber boots over the photodiode & 850 nm laser on the right.
PCB Bottom
Here the PCB has been completely removed from the frame, the fibre ends slide into the rubber tubes on the right.
PCB Top
Top of the PCB, showing the chipset. There are a pair of adjustment pots under some glue, next to the chipset, presumably for adjusting laser power & receive sensitivity. The laser diode & photodiode are inside the soldered cans on the right hand side of the board, with the optics required to couple the 850nm near-IR light into the fibre.
Here is a Inductive charger designed for the Nintendo DSi. Cheap Chinese build, but it does work!
Overview
Top has been removed from the unit here. Most prominent in the centre is a solid steel bar, simply there to give the device some weight.
Pair of Tri-colour LEDs at the front indicates charging status.
Induction coil is on the left, with the controller & oscillator PCB at the top.
PCB Closeup
Closeup of the PCB, ICs have had their markings ground off.
Coil
Induction coil. This couples power into a coil built into a special battery, supplied with the base, to charge it when the DSi is placed on the dock.
Label
Information Label on the base.
Power Input
Standard DSi charger port, connects to the charger you get with the DSi. Power switch is on the right.
Here is an old type KVM switch, PS/2 & VGA interface.
Label
Details Label
Top Removed
Top removed from the main body, the cables coming in from the bottom connect to the VGA, keyboard & mouse ports on the slave computers, the connectors at the top connect to the single monitor, keyboard & mouse.
PCB
PCB removed from the body. This is driven by a PIC16C57C-04 microcontroller.
The pair of LEDs indicate which computer is using the peripherals at any one time.
Here is a cheap USB 8-in-1 card reader. Power & Access LEDs are on top left.
PCB Top
Top of the PCB. The OTi IC is the interface IC to the USB port, part number is OTI002126. Card sockets on the top here are CF/Microdrive & Memory Stick.
Top removed from the mouse, the ball fits in the gap in the centre. The slotted discs are visible which contact the ball & move relative to the surface the mouse is on.
PCB
PCB removed from the shell. Pairs of IR LEDs & Phototransistors make rotary encoders with the slotted discs. The microswitches read the mouse buttons & wheel.
IC in the centre interfaces with the PC over a PS/2 connection.
This is a device to use an IDE or SATA interface drive via a USB connection. Here is the front of the device, IDE interface at the bottom, 2.5″ form factor.
PCB Top
PCB removed from the casing. USB cable exits the top, 12v DC power jack to the left.
SATA interface below the DC Jack.
Molex connector below SATA is the power output for the drive in use. This unit has a built in 5v regulator.
PCB Bottom
Bottom of the PCB showing the interface IC.
Drive Adaptor
Adaptor to plug into the 44-pin 2.5″ form factor IDE interface on the adaptor, converts to standard 40-pin 3.5″ IDE.
Power Cable
Power pigtail with standard Molex & SATA power plugs.
An old IDE interface Zip drive. This fits in a standard 3.5″ bay.
Cover Removed
Top cover removed from the drive, IDE & power interfaces at the top, in centre is the eject solenoid assembly & the head assembly. Bottom is the spindle drive motor.
Head Assembly
Head assembly with the top magnet removed. Voice coil is on the left, with the head preamp IC next to it. Head chips are on the end of the arm inside the parking sleeve on the right. Blue lever is the head lock.
Controller
Controller PCB removed from the casing.
Spindle Motor
Spindle motor. This is a 3-phase DC brushless type motor. Magnetic ring on the top engages with the hub of the Zip disk when insterted into the drive.
Magnets
Magnets that interact with the voice coil on the head assembly.
Head Armature
Head armature assembly removed from the drive. The arm is supported by a pair of linear bearings & a stainless steel rod.
Old iPod with damaged screen. Here is the front with the Click Wheel.
Cover Removed
Cover removed from the back, here the HDD is the biggest visible part.
Mainboard
Back cover removed from the unit, here is the back of the screen & the main PCB.
Back Cover
Back cover with the battery & headphone jack PCB.
Battery
Closeup of the Li-Ion battery.
Front Removed
Front removed from the unit, the touch sensitive Click Wheel PCB is folded away from the mainboard here.
Buttons
Tactile switches underneath the Click Wheel.
HDD
1.8″ hard drive. Toshiba MK3008GAL.
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