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Sony PS3 APS-231 Power Supply Voltage Mod

PSU Ratings
PSU Ratings
PSU Ratings

I was recently given a Sony PS3 with a dead disc drive, and since I’m not a console gamer I figured I’d see if there were any handy parts inside. Turns out these units contain a rather nice SMPS, the Sony APS-231 with a high power 12v rail, rated at 23.5A. A bit of searching around discovered a thread on the BadCaps Forums about voltage modding these supplies for a 13.8v output, suitable for my Ham radio gear.
These supplies are controlled by a Sony CXA8038A, for which there is very little information. Active PFC is included, along with synchronous rectification which increases the efficiency of the supply, and in turn, reduces the waste heat output from the rectifiers.

Regulation Section
Regulation Section

Like many of the SMPS units I’ve seen, the output voltage is controlled by referencing it to an adjustable shunt reference, and adjusting the set point of this reference will in turn adjust the output voltage of the supply, this is done in circuit by a single resistor.

Here’s the regulator section of the PSU, with the resistors labelled. The one we’re after changing is the 800Ω one between pins 2 & 3 of the TS2431 shunt reference. It’s a very small 0402 size resistor, located right next to the filter electrolytic for the 5v standby supply circuit. A fine tip on the soldering iron is required to get this resistor removed.

Attachment Points
Attachment Points

Once this resistor is removed from the circuit, a 1KΩ 18-turn potentiometer is fitted in it’s place, from the Anode (Pin 3) to the Ref. (Pin 2) pins of the TS2431 shunt reference. I initally set the potentiometer to be the same 800Ω as the factory set resistor, to make sure the supply would start up at a sensible voltage before I did the adjustment.

Potentiometer
Potentiometer

The pot is secured to the top of the standby supply transformer with a drop of CA glue to stop everything moving around. The supply can now be adjusted to a higher setpoint voltage – 13.8v is about the maxumum, as the OVP cuts the supply out at between 13.9v-14v.

Modded Voltage
Modded Voltage

After doing some testing at roughly 50% of the supply’s rated load, everything seems to be stable, and nothing is heating up more than I’d expect.

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AIX Gigabit Ethernet To USB Bridge

USB To Ethernet
USB To Ethernet

Here’s a chap eBay USB-To-Ethernet dongle I obtained for use with the Raspberry Pi Zero. This one is getting torn down permanently, as it’s rather unreliable. It seems to like having random fits where it’ll not enumerate on the USB bus. The silicon in the ICs will eventually make it here once I manage to get a new microscope 😉

Main Chipset
Main Chipset

This is quite a heavily packed PCB, with the main Asix AX88178 on the left. This IC contains all of the logic for implementing the Ethernet link over USB, except the PHY. It’s clock crystal is in the top left corner.

Reverse Side
Reverse Side

Not much on the reverse side, there’s a 3.3v linear regulator at top left, the SOIC is an Atmel AT93C66A 4KB EEPROM for configuration data.

Vitesse PHY
Vitesse PHY

The final IC in the chain is the Vitesse VSC8211 Gigabit PHY, with it’s clock crystal below. This interfaces the Ethernet MAC in the Asix IC to the magjack on the right.

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eSynic 2-Way HDMI Signal Splitter

HDMI Splitter
HDMI Splitter

Time for another random teardown, a signal splitter for HDMI. These units are available very cheap these days on eBay. This one splits the incoming signal into two to drive more than one display from the same signal source.

Main PCB
Main PCB

The stamped alloy casing comes apart easily with the removal of a few screws. The PCB inside is rather densely packed with components.

Chipset
Chipset

The main IC on the incoming signal is a Silicon Image Sil9187B HDMI Port Processor, with a single input & 4 outputs. In this case the chip is used as a repeater to amplify the incoming signal. the signal path then gets fed into a Pericom PI3HDMI412 HDMI Demux, which then splits the signal into two for the output ports.

Microcontroller
Microcontroller

The main pair of ICs processing the video signals are controlled over I²C, with this STM32 microcontroller. The 4 pads to the lower left are for the STLink programmer. The main 3.3v power rail is provided by the LM1117 linear regulator on the right.