2018-02-17

Repairing an HP Pavillion DV6 Motherboard

Here's my procedure on how to replace the logic board of an HP Pavillion DV6.

My model is a DV6-3122US, and many DV6s of the 3000 series are similar.

These machines often fail to start due to a motherboard failure.  With a motherboard failure, upon pressing power the fan will first spin and the power light comes on.  The capslock key will flash white once every 4 seconds, and the f12 key will stay a solid orange, and the screen displays black only.

Although the caps lock "single blink" indicator at boot implies a CPU failure, in my experience it is not due to the CPU itself but the supporting components on the motherboard.  The only solid solution is to repair or replace the motherboard.  Replacement boards are readily available.  I bought one and replaced it myself

Disassembly Procedure

NOTE: The screws are different sizes, and its important to reinstall them correctly.  I color-coded the different screws in the photos below and refer to them in the text.



  • Unplug laptop
  • Remove battery
  • Remove bottom access plate panel
    • Loosen the four captive screws (magenta)
    • Pry up the access panel
  • Remove screws around perimeter (8).
    • Note that the long screws (red) are in the corners by the display hinge.
    • The other six screws (orange) are of medium length.
  • Remove the three screws in the battery compartment
    • Two short screws (yellow)
    • One very short screw (green).

  • Remove 5 short screws (red) in the access panel compartment.
  • Remove the CD Drive
    • Remove the very short screw that retains the CD drive (orange) 
    • Remove CD drive by sliding it out
  • Remove WiFi card:
    • Remove two short screws holding in WiFi card (yellow)
    • Remove two antenna connectors
    • Withdraw the WiFi card
  • Unlatch all electrical connectors under access panel
    • Hard drive SATA cable: pull up on connector
    • trackpad: flip up connector and slide out cable
    • CD SATA cable: pull up on connector
  • Remove Keyboard:
    • Flip over and lift display to vertical position
    • Partially release keyboard from upper case, pulling from the top.
    • Flip up and detach the keyboard cable
    • Fully remove keyboard
  • Detach all connectors under keyboard
  • Remove top case
  • Remove logic board:
    • Unplug all electrical connectors under access panel
    • Verify that all connectors have been removed from motherboard
    • Withdraw motherboard
  • Remove CPU:
    • Unplug fan connector
    • Loosen three captive screws which attach heat sink to motherboard
    • Remove heatsink with fan
    • Turn screw latch holding CPU in socket with a flat head screwdriver
    • Remove CPU

Reassembly:

  • Install CPU:
    • Insert CPU into socket
    • Turn socket latch to lock CPU into socket
    • Clean mating surfaces of CPU and heatsink
    • Re-apply heat sink compound
    • Re-attach heat sink to motherboard via three chrome screws
    • Plug in fan connector
  • Reverse above disassembly instructions

2018-01-31

Nest Smart Thermostat Stupidity

Smart Thermostats are stupid.  $250 for what amounts to a $30 thermostat with $10 of extra smarts and a $180 display is simply insane.  Then you add the installation costs and security risks and the risk that it will become useless within 15 years and it becomes clear that Smart Thermostats are a very very stupid investment.

I have new approach.  I call it the Better Smart thermostat.  It costs the same as today's inexpensive "dumb" Programmable thermostats, but has 100% of the capabilities of the Nest.

Take today's $30 thermostat and keep it as a regular, simply-programmable thermostat.  It has a temperature sensor, a display, and some relays for turning the systems on and off.  Then add BLE (Bluetooth Low Energy) to give it the ability to get hints from an external device.

That's it.  No fancy display.  No special wiring.  No 802.11n.  It uses BLE, so it can use regular AA batteries.

But with BLE on-board, some significant opportunities emerge.  Now the thermostat settings can be easily modified from an app on a iPhone or iPad.  Away from your house?  Enable Away mode.  Coming home?  Enable Home mode.  Super-cold weather?  Fire up the heat earlier.  Daylight Saving changes?  Fix the time of the clock.  Temperatures approaching freezing?  Trigger an alarm.  Record temperature history.  Key track of "system on" energy use.  Program setback schedules from a computer.

Need 8 for your electric heat radiators?  Great, you can afford 8.  Unlike the Nest and their insanely designed counterparts.

And if BLE becomes obsolete, or if you simply don't care about smartness, you still have a 100% good and secure thermostat. 

2018-01-26

Apple-Supplied MacBook Battery Weight Matters

How much should a MacBook battery weigh?  Great question!  I buy a lot of aftermarket batteries for MacBooks, and judging by weight, it is clear that 3rd party batteries are lighter than the originals.

That means that the aftermarket batteries simply cannot provide as much power.

Analysis:

There are three parts to a battery:
  • The housing
  • The management electronics
  • The lithium cells
So let's think of everything that makes up a battery except the lithium cells: It seems like a good bet that a genuine Apple battery's housing and electronics has about the same weight as an aftermarket battery.  For argument's sake, let's say that a battery unit weights 100 grams PLUS the weight of the cells.

That implies that a lighter battery has smaller (or fewer) cells!

For example, I have a genuine MacBook battery that weights 364 grams.  My aftermarket battery weighs 270 grams.  Assuming that 100 grams is for non-cell componentry, that means the genuine battery has 264 grams of cells versus 170 grams of cells for the aftermarket battery.

Doing the math, that means that the genuine battery has 55% more battery than the aftermarket battery.  Although the batteries are rated the same, it is virtually impossible that they deliver the same power.

What about my battery?

Well, each Apple battery model has a weight.  Below is a list of original MacBook batteries that I've measured.  Check to see how your MacBook battery measures up!

MacBook Air, 13 inch 

Apple Battery Model Number: A1405
Power Label: 7.3VDC, 50Wh, 6700mAh
Weight: 296 grams (Source: MacBook Air 13-inch (mid-2012) 020-7379-A)

All of these MacBook Air models use the A1405 form factor:
  • Apple MacBook Air 13 inch, Late 2010
  • Apple MacBook Air 13 inch, Mid 2011
  • Apple MacBook Air 13 inch, Mid 2012
  • Apple MacBook Air 13 inch, Mid 2013
  • Apple MacBook Air 13 inch, Early 2014
  • Apple MacBook Air 13 inch, Early 2015

MacBook Pro, 15 inch Unibody

Apple Battery Model Number:  A1321
Power Label: 10.95 VDC, 73 Wh
Weight: 450 grams (Source: MacBook Pro 15-inch (mid-2009) 020-6380-A)

The following MacBook Pro models use the A1321 form factor:
  • MacBook Pro 15.4 inch, Mid 2009
  • MacBook Pro 15.4 inch, Mid 2010

MacBook, 13 inch Unibody (white)

Apple Battery Model Number:  A1331
Power Label:10.95 VDC, 63.5 Wh
Weight: 364 grams (Source: Two MacBook 13-inch (mid-2010) 020-6809-A batteries)

The following MacBook Pro models use the A1331 form factor:
  • MacBook 13 inch, Late 2009
  • MacBook 13 inch, Mid 2010
My aftermarket A1331 compatible battery:
Rating Label Claim: 10.95V, 5800mAh/63.5Wh
Weight is 270 grams.

MacBook, 13 inch (white polycarbonate non-Unibody)

I haven't measured a geniue Apple battery for these models, but I do have details for my aftermarket battery.  If you have a genuine Apple battery, please let me know the details!

Apple Battery Model Number: A1185
Power Label:
Weight: ??? grams (Source: Maybe you?  Let me know!)

The following MacBook models use the A1185 form factor:
  • MacBook 13 inch, 2006 through mid-2009
My aftermarket A1185 compatible battery:
Rating Label Claim: 10.8V, 5600mAh/60Wh
Weight is 280 grams.
Note: the aftermarket battery has a housing that is all plastic, instead of partially aluminum

2018-01-22

Repairing a MagSafe Charger's Cord

Apple MacSafe power adapters can get a lot of use, and their cords are quite robust.  But they do fail, leading to no function or poor reliability.

Cats chew on them.  They get wound tightly very often.  They get yanked and tripped over.  And they get pinched by doors and furniture.

All this abuse can ruin the MagSafe cable.  The power brick itself is usually fine, but the cord needs repairing.

In this article, I show how to repair a MagSafe cord.

Here, we see a Magsafe cord with damage.  We're going to make it right again for just a little amount of effort.

Required:
  1. A Soldering Iron kit, like this one, including a low-wattage soldering iron, rosin-core Solder, and wire strippers
  2. Heat shrink tubing
  3. One Soldering Sleeve, appropriate for 22 or 24 AWG wire
  4. Heat gun (optional)
Process:

1. Using wire cutters, cut the cable, removing the flawed section.  The flawed area might be obvious due to a tear or a bite mark.
Cut out bad section of the cord

2. Slide a roughly 2 inch piece of heat shrink tubing over one of the wires.  It should be pushed down far away from the end of the cable that is being worked on in order to prevent it from shrinking too early.


Slide on heat shrink tube

3. On each end, strip about 1 inch off of the outer plastic coating of the outer wire
4. Twist the metal wires together, revealing the internal wire.


The outer sheathing is twisted on both ends

5. Strip about a quarter inch of the insulation off of the inner wire.
6. Twist together the external wires.

The external sheathing is rejoined by twisting. The inner wires are striped
7. Solder the external sheathing together.
8. Allow work to cool (about 5 minutes) 
External sheathing is soldered together

9. Stick solder sleeve into place in order to join inner wire.  Trim solder sleeve as necessary.
Solder Sleeve
Solder Sleeve, trimmed and placed over joint

9. Heat solder sleeve until its internal solder melts and the sleeve shrinks tight.
10. Allow for work to cool (about 5 minutes)

Activated Solder Sleeve


11. Slide heat shrink tube over exposed "wound"
Heat shrink tube over wound

12. Shink tubing with heat source.

13. Test.  Success!











2018-01-21

The $18000 cup of coffee

$1 a day is a lot of money.
  • It's $365 a year.
  • Estimating that you pay an average of 15% interest on your credit card, you'll pay $420 a year for that $365 dollar a year cost.
  • Do you pay wage taxes?  Assuming 30% taxes, that means you need to earn $600 in your paycheck to cover that $420 a year financial expense.
  • Adding it all up over ten years, you need $6000 to pay for $1 per day
So remember:
  • the $8 dollar sandwich instead of the $7 sandwich costs you $6000.
  • the $3 coffee instead of the free cup of water costs you $18000.
Next Steps

The next step is to start getting cheap.  Stop buying ANY stuff that isn't needed, and skip extra expenses.  Take any savings and pay off  debts.  Once debts are gone, there is a lot more money to spend.



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