Dell PR03X docking station

Dell PR03X docking station - with USB 2.0. Works with laptops based on Arrandale/Clarksfield (i5 540M etc.):
  • Latitude E4200
  • Latitude E4300
  • Latitude E4310
  • Latitude E5400
  • Latitude E5410
  • Latitude E5500
  • Latitude E5510
  • Latitude E6400
  • Latitude E6400 ATG
  • Latitude E6400 XFR
  • Latitude E6410
  • Latitude E6410 ATG
  • Latitude E6500
  • Latitude E6510
  • Precision M2400
  • Precision M4400
  • Precision M4500
  • and more?

 Reason of death: bent pins on main connector and (probably) obsolescence.

 TPS2066A - two channel current-limited power distribution switches.
AO4423 30V P-Channel MOSFET, Rdson = 6...7 mOhm

 8 layer PCB.

Si4634 MOSFET?
 ECE1099 - GPIO expansion
4800B - Si4800BDY N-Channel Reduced Q , Fast Switching MOSFET
USB2513 (2 pieces) - 3 port hub controller


 SSM2603 - low poer audio codec from Analog Devices with headphone amplifier, stereo line input, mono microphone input; I2S


Toshiba Canvio Basics external HDD

Cheap external USB 3.0 HDD - 2.5", 1GB.

 MQ01ABD100 HDD.
VIA Labs VL711S USB to SATA bridge.


  • cheap (~$50 in 2015 or so) 
  • still works (albeit lightly used)



IIYAMA E2274HDS (PLE2274HDS-B2) monitor

I've got this monitor for free as previous owner gave up on fixing it.
Symptoms: monitor works fine at first look, but after hour or so it may randomly turn off or start showing image with weird colors (e.g. missing one color entirely). OSD menu has often random minor artifacts. It cannot be turned on again using ON/OFF button but with powered off entirely (detaching power cable) for few minutes it starts working correctly again for a random time. Sometimes image might get really weird:

 From the posts on few forums this is common issue with this model and also with larger XB2374HDS and E2475HDS / B2475HDS. Two possible problems are listed: failure of NOVATEK NT68677UMFG chip (scaler) and failure of serial EEPROM (A25L02). Some suggested that main chips are just faulty and need replacement, but my plan for now is just trying to lower it temperature using radiator from old Pentium 4 motherboard north bridge. After testing for a few days this radiator seems to be helping, not fixing all problems (like not powering on after signal going down and then up) but reducing them significantly (hours of work but still need to cut down the power once or twice per day).
 PAM8007 - class D power amplifier, 2 x 1.5W @ 4Ohm, 10% THD, 5V supply.

 Audio quality is very poor as nothig separates the front and the back of the speaker. Perhaps some piece of plastic is missing from this unit? Otherwise this would be just poor design - sacrificing audio quality for like a dollar.

Monitor is using PWM for brightness control - it is working with 240Hz frequency right after brightness is reduced below 100Hz.


Grundig Music 51 radio

Small portable FM PLL radio with clock and alarm - RP 5201 PLL. Retail price: ~$25-$30.

 2 R6 cells for clock / station memory backup (optional), 4 R14 cells or 230V AC for full operation.

 Decent speaker.
 Two keyboard boards connected with single wire pair each - reading keys by measuring resistance.
 This one is incomplete - transformer is missing, otherwise it works fine. Mains socket is couples with mechanical switch disabling internal battery.

Power supply filtering is very impressive for this class of products - there are 3 coils, 2200uF + 1000uF + 2 x 470uF + 6x 220uF + 100uF (one of these might be DC decoupling for speaker actually).
Audio amplifier: "CHMC S75"/"D820"
Microcontroller: TMP86FM29LUG. Toshiba, 8-bit TLCS-870/C series, 32kB FLASH, 1.5kB RAM, 10bit x 8ch ADC, built-in LCD driver, dual clock. Supply current 4.5mA typ, 8-20uA in SLOW/SLEEP modes. UART bootloader.
 Coils on small board resembling hybrid circuit.
 Radio chip.

Both reception and audio quality is pretty decent.
It's worth noting that apart from 2xAA clock/station backup it seems to retain memory with energy from capacitors for a minute or so.