2019-09-28

Dell E6440

Keyboard: from my perspective worse than in T500. Finding F5 of F9 without looking would not be easy. No separated Del/Home/End/PageUp/Down block. Similar, yet somehow less intuitive cursor block indentation. The problem is no one if making "proper" keyboards since T420/T520. On a plus side: separated volume up/down buttons - something that is missing in T440/T550 (equivalent generation from Lenovo).
One pretty annoying thing is squeaky sound from right Shift button - I'm guessing this button might be slightly too wide for used mechanism.
Bottom cover is made from metal, but when detached it is rather thin and flimsy - this is not like T500 back cover that could basically be skeleton. It is held by 4 screws (3 on the HDD/left side and in the center) and - at least on my unit - it does not fit perfectly on right side. I wouldn't mind few extra screws.



Rather weird looking speakers, with two membranes each. Magnets are quite strong and they are catching metal dust.
The good: battery life at low backlight level seems excellent - for my 48Wh (effectively) battery work time is estimated as 9 hours.
It is very easy to recover Windows - Dell supplies tool that creates bootable USB.
Buttons for trackpoint are disappointing (buttons below trackpad are OK) - they need to be pushed all the way down but they are flat and have no tactile feedback.
My previous laptops were Thinkpad R500 and T500 and comparing to them E6440 seems little loud and hot - fan is spinning in situations when it was idle on thinkpads. Currently I'm using ThrottleStop I'm experimenting with undervolting using ThrottleStop with voltage offset -100mV for CPU Core, Intel GPU and also for CPU Cache. This might be helping a little, but R500/T500 still were better.
Display viewing angles are poor, but on the plus side there is no visible flickering starting from third (out of 16) level of brightness. Brightness is also noticeably higher than on '500 series thinkpads.

Note: to get service number run wmic bios get serialnumber

AN8008 multimeter

 Differences from AN8009:
  • no NCV (Non-Contact Voltage detection)
  • no temperature measurement
  • square wave generator output (not present in AN8009)


Bottom part looks like rubber holster, but it is actually single piece of plastic.


ICL8069 as reference voltage source.

24C02 - most likely for calibration storage.
PCB markings: ZT109 V0.4 170213 => http://zotektools.com/products-2/zt109/
Range switch is not the best I've seen.
Buzzer is latching and reasonably quick, but personally I would prefer "analog" one.
My other complaint would be rather poor display visibility when looking from angles above it (from below it is fine).
Note: auto power off can be disabled by holding SEL/HOLD button while powering on. Multimeter would still beep after each 15 minutes or so as when auto power off normally would be about to trigger.

2019-09-18

Disabling HDD APM

APM (Advanced Power Management) feature is quite problematic for my 2.5" laptop disk - 500GB HGST HTS545050A7E680. Depending on disk activity it might unload heads way too often - every minute or so. This is annoying (clicking noise), increases mechanism wear and probably even increases power usage when it semi-randomly parks head just to activate again few seconds later. I have no idea why so short idle time was selected as default in firmware - just an error plus lack of testing or planned obsolescence.
CrystalDiskInfo can be used to disable APM, but it gets little tedious as this has to be repeated each time disk is powered on and requires few clicks each time.
Here is another tool - APMdisable.exe from https://www.codeproject.com/Tips/808412/Disable-APM-for-Hard-Drive-in-Windows. Changing disk parameters require administrator rights - set this in file properties.
To run APMdisable.exe each time disk is powered on I've used Task Scheduler, creating new task triggered by "On workstation unlock of any user" event - as described on https://superuser.com/questions/15596/automatically-run-a-script-when-i-log-on-to-windows:
 Important: "Run with highest privileges" - set this also in APMdisable.exe properties.
Add also second trigger: "At log on"/"At log on of any user" - apparently logging first time after restart does not count as "On workstation unlock".
 Command line arguments: "-dis"
Starting both when using battery and AC power.

Also: set "Require a password on wakeup" in Control panel -> "Power Options".

2019-09-14

Halogen oven

Cheap (~$27) halogen oven. 220-240V, 1200-1400W, single circle-shaped heating element.
Nominal capacity 12l, with extender ring - 17l.













Bottom of the bowl diameter: ~28cm.


 It seems like it also suitable for baking (about 45 minutes for plum cake, using higher grate, 170C, lowered to 150C after about an hour).


2019-08-17

Electric kettle repair

Cheap electric "cordless" kettle with round base, sold probably under hundreds of brands.
Advertised and looking like made from brushed steel, although weirdly this is non-magnetic metal.
Symtoms: randomly not working at all (no neon light near the switch, no heating). Mischievously working once or twice after disassembling and reassembling.

 Faulty element: electric switch with integrated thermal switch (aka thermostat switch) - original marking DY-03G T125.
 It might be not worth the effort, but replacement switch is easily available on ebay (TM-XD-3 T125 and various other names), costing $0.99 with free shipping. Disassembling, replacing switch and reassembling kettle is pretty straightforward.
This metal plate at the bottom of the switch is actual element responsible for switching off when boiling starts - it pushes plastic rod inside when temperature arises.