Z-Car

2011 MacBook Pro GPU Failure – A software fix to disable GPU

Last year I repurposed a 2011 Macbook Pro 15″ as my home media server.  This laptop had been my main machine for a couple years until I upgraded in 2015.  Early in its life, I had used gfxCardStatus to disable the discrete AMD graphics card.  I mainly did this because I did not need the performance, and it definitely affected battery life negatively.  Because of this, I never was aware of the issue that thousands of other MacBook Pro owners experienced, a failing GPU causes the machine to either not work at all, have odd display effects, or reboot when video modes are switched.

About a year after using this machine as my main media server, it started to randomly reboot.  I could not find anything that was causing it, it would just be running fine, and then reboot.  I did notice that if I started up the machine, but did not login to a user account, it would stay running for quite awhile.  After some online research, I soon found out about all the issues that have plagued this machine.  The AMD GPU seemed to be the most likely culprit.  After finally having the machine stay running long enough for me to reinstall gfxCardStatus, I determined that I could immediately crash the system just by switching graphics modes.  Success, I was finally able to confirm that the GPU was failing.

Because I do not have any application that requires the GPU, I realized if I could somehow disable it, I could be back in business.  After extensive searching, I found lots of partial solutions, many required booting with Linux, putting the logic board in an oven, or trying to cut power traces on the motherboard.  After lots of reading, I finally was able to come up with a solution that worked, one that did not require opening up the laptop, or installing Linux.

My machine is a basic system running High Sierra, version 10.13.  I have confirmed that this works, although I did not try with previous versions.  If you have a highly modified system with lots of custom kexts, it may not work.   This modification will force the laptop to not boot into discrete graphics (dGPU) but directly into integrated graphics (iGPU).  While you will now be able to use your system you will lose the ability to use an external display.  Thunderbolt data and video connections should continue to work as normal.   It also assumes that all kexts are still in their default location /System/Library/Extensions, all AMD-kexts remain except one which is required to be moved.

Let’s get started!

Power on your laptop while holding <Cmd>+<r>+<s>, this will get you into Recovery/Single-User mode.  If your machine will not boot up into this mode, you can try putting it into a freezer for 10-15 min beforehand.  If you can keep the machine cool, it should let you boot to a command prompt.

The first step is to disable SIP.  This is done by entering : csrutil disable 

This is a critical step, as the following commands will not run unless you disable the default SIP protection.  You can leave this off permanently, or re-enable after you complete the whole process.  At this point, reboot the laptop by entering : reboot

This time hold down <Cmd>+<s> to boot into single-user mode.  We will then issue commands to disable the AMD GPU on boot by writing specific values into the NVRAM.  

Enter : nvram fa4ce28d-b62f-4c99-9cc3-6815686e30f9:gpu-power-prefs=%01%00%00%00

Enter : nvram boot-args=”-v”

This will turn on verbose mode when booting up.

One again : reboot

Hold down  <Cmd>+<s>  on boot

Next we will want to move one AMD kext so that it is not loaded on initial boot.  We will just move it, because after the machine boots up and you login, we will want to reload it.  This will keep the GPU disabled, but also will remove power from it so that it keeps your system cooler.

Type the following :

mount root partition writeable
/sbin/mount -uw / 
mkdir -p /System/Library/Extensions-bkup 
mv /System/Library/Extensions/AMDRadeonX3000.kext /System/Library/Extensions-bkup/ 
touch /System/Library/Extensions/ 
mkdir -p /Library/LoginHook
nano /Library/LoginHook/LoadAMD.sh

In nano, add the following text and hit control-X to save

#!/bin/bash
kextload /System/Library/Extensions-off/AMDRadeonX3000.kext
exit 0

You should have a saved file called LoadAMD.sh at this point.  Now type : 

chmod a+x /Library/LoginHook/LoadAMD.sh
defaults write com.apple.loginwindow LoginHook /Library/LoginHook/LoadAMD.sh 
reboot

This time, let the machine boot up normally

Reboot normally and your machine should work normally, however you will have an accelerated iGPU display.  This process will most likely need to be repeated when you do any system upgrade.  The NVRAM setting should stay, however you most likely will need to move the AMDRadeonX3000.kext file again.  Just make sure that if a new version is used, you save each.  

Hopefully this will allow your machine is provide several more years of service.  Leave me a message if you have any questions, and/or you will successful.


How to add DRL and LED to your Miata NA.

girl fixing a miata

As I have been daily driving my 1994 Miata NA for the last year or so, I have been more cognisant of trying to make the little Miata more visible. We also have a lot of divided highways out this way that require headlights to be on, and the police enforce it. I hate raising the barn doors, and if I just turn on my parking lights, they don’t really do much, and I always forget that I left them on.

So, I decided to get a couple of smoked replacement lights ($50 on Amazon for a pair), and modify them. I opened up the unused half of the light and used a LED for the parking and turn signal, and used the main bay with a H11 LED.  If you follow along, I will show you what you need to do to make this work.  In addition, you can easily wire in a relay to make your parking lights come on whenever the car is running.

First get some of these nice smoked turn signal assemblies.

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Then buy a set of 3157 parking and turn signal bulbs, I like these, and get this pigtail harness.  I also used H11 LED bulbs as the main DRL, I got these, and also the pigtails.  What we are going to do is open up the normally closed section on the parking light assembly.  I used a soldering iron to melt it out.   Once you get a good fit, a glob of silicone sealant will hold them in place and seal the opening from moisture.

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You will now need to wire the lights up.  This will vary by pigtail, lights, and assembly, but in general you will want to wire red to red and black to black.  The blue for the turn signal light will connect with the turn signal light coming from your original parking light wiring.  This is all pretty simple, leave a message if you have any issues.

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As you can see, it worked out pretty well. I wired in a relay that turns them on whenever the the car is in Run, instant DRL. I also wired the side markers to flash with the turn signals.

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How to Repair a Lotus Switch Pack – Or, why don’t my Elise’s parking lights work?

LotusGirl

Odds are you are either reading this page because your Lotus parking lights suddenly stopped working and you don’t know why, or you already know you need to replace or repair you Lotus Switch Pack.  That is great, because either way I will help you solve your problem.

I normally do not drive the Lotus that often in the Winter, and sometimes it can sit for a month or so with no venture outside.  This Winter was no different, and in addition, I had to get it moving at the beginning of March because I needed to get it emission tested.  That all went great, however when driving home I went to turn on the parking lights because it was misting slightly.  Imagine my surprise when the parking lights refused to turn on.  However, everything else worked, headlights, flashers, hazards, etc.  After looking at the schematics, it looked like Fuse F6 could be the issue.  I checked it, but it was fine.

Ok, this was not going to be a simple fix.  Maybe the switch was bad?  Remove the panel on the left that holds the switches, two screws on bottom, swap headlight switch connector and parking light connector.  As expected, parking light switch would turn on the headlights, so the problem was not the switch.   This panel is displayed below, the two green connector at bottom left are the ones you want to swap.

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After some more reading, and reviewing the Elise electrical schematic, it became pretty obvious the issue was the infamous Lotus Switch Pack pictured below!

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So, where is this Lotus Switch Pack located?  It is mounted on the steering column behind the instrument cluster.  Some online guides will tell you need to remove the full dash to get to it, however that is not true.  You can get to this by removing the cluster cover, unbolting the instrument cluster, and moving it out of the way.  Here is how you do it.

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First, remove (4 or 6 screws depending on if car was built on a Monday or Wednesday) the bottom cover around steering wheel.  One or two screws on each side, and two screws on the bottom.  Remove the top and bottom cover.  Then, you need to remove the instrument cluster housing.  This part sucks.  Remove two screws on each side.  The back of the cluster is just velcroed in place, yep 50K car uses velcro…  That part is easy, just lift up slightly.  The next is hard.  You need to pull the whole cluster back straight to release clips holding it on.  This requires pulling hard, if it does not come out, pull harder.  Take your time, and try not to crack anything.

It should look like the below when all is removed.

IMG_1725

I did not get a picture of the unit installed, but imagine in the picture below it is connected to those two connectors, and is mounted vertically with a screw on each side.  That part is easy, remove two screws, release the connectors.  There is a tab in center of connector you need to hold down while pulling carefully on connector.  Wiggle as needed.

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Success, you now have the Lotus Switch Pack module in your hands.  At this point, you have two choices, you can either simply buy a replacement, or you can attempt a repair.  If you decide to buy a replacement, you will need to search for the proper unit.  My 2005 Lotus was part number C117M0008f.  This has actually been superseded by two newer model numbers, D117M0008f was used in some later models, and E117M0008f appears to be the current replacement model.  I was able to find new versions online for between $160-$250.

However what if I told you that you could repair the unit for free? Worst case, for less than $25.  So, how do you do this?  Read on.

Inside the Lotus Switch Pack are two little relays, and one of them is preventing your parking lights from working.  The other relay is installed for the factory fog lights, which in many cases will not be installed on your Lotus.  You will know because you will have a fog light switch below the headlight switch.  If you don’t have fog lights, you can simply swap relays and solve your parking light issue.

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If you remove the switch pack module cover, you will see the guts of the unit.  On the top are relays, which are soldered below.  If you look carefully below (taken after removing the fog light relay), you will see five empty holes.  These are the five connections that you need to desolder.

IMG_1731

The picture below shows the relays.  The one in the center is the fog light relay, the parking light relay is directly below.  You will need a desoldering vacuum pump and/or desoldering wick.  Carefully remove ALL the solder from the relays and gently rock them loose.  There is some sticky substance that causes the relays to adhere to the board, be careful as it is easy to damage the relay when removing.  In fact, my guess is there is a 50/50 chance that it WILL be damaged, so be prepared to have to replace the relay.  If you email me or leave a comment with your contact info, I can provide replacements that WILL work with your unit for $25.  If you purchase on your own, be careful of your source, as it appears there are a lot of used units on eBay that will not work.

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How do you know if your relay is good or bad?  If you measure the coil with your ohmmeter, it should have a value between 120-140 ohms.  The proper pins to  test are the outer pins of the three in a row.  In picture below, it would be the pins that go into the three holes in the center.  Here you can see that I have removed the fog light relay, and replaced the parking light relay with a new unit.

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Connect the unit back up, and if you press the button, you should hear the relay click, and you now have parking lights!

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Put everything back together in the reverse order, and have a cold one.  Think about the $750 you saved by not going to the dealer, and leave a comment with your success story.  If you have any questions on the process, connect me and I will see what I can do to help you out.  Good Luck!

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Moen shower faucet provides no cold water, only hot

hot-girl-cold-broken-shower

A common issue with older Moen shower faucets is only cold, or only hot water coming out of the faucet or shower head.  This often happens with showers that are not used very often, or where the water supply is particularly hard or has high levels of contaminants.  If you search the web for help, the most often suggest is to replace the main cartridge (part number Moen 1225 or 1200).  However, this is most likely not the source of the issue.

If you remove the shower faucet knob, and remove the cover behind it, you should see something like the image below.  This is a Moentrol 3570 valve, there are other similar model numbers.

moenvalve

Within the valve is what is called a balancing spool.  This balancing spool valve contains a piston which moves back and forth maintaining a given temperature even if the pressure on the cold side is reduced, for example someone flushes a toilet when the shower is in use.  It prevents a sudden blast of hot water which can lead to burns.  When you suddenly experience only the cold or hot water flowing regardless of where you set the flow handle, this valve is almost always the culprit.

The piston which is inside the balancing spool will get stuck in one position or the other.  When this happens, it essentially shuts off flow to either the hot or cold side.  Poor water quality and age will eventually cause the piston to get stuck in its bore.   The balancing spool (part number Moen 1423) can be seen clearly in the photo below.

moentrol valve

The first step in repairing the balancing spool valve is to remove it.  You will need to use a VERY large screw driver to unscrew the valve (number 2 above).  Make sure you shut off your water first!  You can also use a straight-edge piece of metal clamped in vice grips if you do not have a large enough screw driver.  Spray the outside of the screw with Liquid Wrench or other penetrating oil in advance of your attempt, it can be difficult to loosen.  If you are lucky, the valve will come out with the screw.  But, most likely the top of the spool will separate, like in the photo below.

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If this happens, you will need to retrieve the stuck piece.  The way that I accomplished this was to soak it in Liquid Wrench for an hour before my attempt.  I inserted a screw driver down into the piston and tried to lever it out, tapping with a hammer at the same time.  I then bent a piece of metal rod into a hook shape and fished it inside and caught it against one of the holes in the body of the spool.  Using a pair of vice grips I pulled until it came loose.  This may take some work, so be patient.

Once removed you have two options, replace with a new one, which is not cheap, retail price is between $55-95.00.  Or, you can usually successfully clean the spool.  To do this, remove the round piece of metal at the back of the valve (seen above).  Just slip a small screw driver into the gap and twist it out.  Then tap the piston out of the bore.  I used a socket to support the back of the spool, and used a hammer and screw driver to tap it out.

Next, you want to use fine sandpaper to clean off the piston journals, and the inside of the bore of the valve.  Get aggressive, you want the bore and journals to be polished clean.  Work the piston back and forth in the bore until there is absolutely no sticking or binding.  Then apply plumbers grease and reassemble.  Turn the water back on and test the faucet, you should now have hot and cold water, and just saved yourself a couple hundred dollar repair bill.


Whirlpool Duet Dryer GEW9250PW1 will not turn on, no lights displayed on control panel.

cute girl doing laundry

I have a Whirlpool Duet GEW9250PW1 that recently began to act up.  The symptoms were multiple, however the basic problem is that after running for a short period of time, the dryer would turn off and the control panel was no longer working.  It was not possible to turn it on.  This would happen randomly, although steadily got worse.  If I unplugged the dryer and tried again the next day, it would magically return to normal and work for some period of time before the problem returned.

Other internet stories have reported related symptoms, such as flickering or dim LED’s, various switches not working, only some cycles operational, etc.  All of these problems can usually be traced back to a flaky control panel (user interface).

This dryer is very similar to other Whirlpool models, such as the GEW 9200L and other Kenmore and Bosch models like the HE3.  They all share many common parts.  The following repair will often work on these models as well.

After a quick look around several of the appliance repair sites, the common suggestion is to replace part number AP3775548 (8546219) which is the control board.   This board controls all of the dryers operations, and the electronic control panel (also known as the touch pad user interface) plugs into it.  In general, if the dryer works, but the user interface responds only intermittently, then this control board is almost never the problem.  The core issue is the control panel, part number AP3775978 (8558753, 8530590, 8530589, 3980189, W10838692, 3979789, 1060819, AH973834, EA973834, PS973834)

duet_control_board

Further research shows that the control panel has two common issues, the first is that the small micro-switches get small amounts of corrosion within them and only operate sporadically if at all.  The second issue is caused by the large number of LED’s that are used on the user interface.  These LED’s are not only used to provide feedback on what selections were made, they are also cleverly used to help multiplex the required signals back to the control board.  These LED’s are very susceptible to having poor soldered connections on the back of the control panel circuit board.

duet_control_board2

So, how to fix it?  It is actually fairly easy.  Refer to the Repair Manual for more detail on removing parts.

  1. Remove the top cover of the dryer (three screws in back)
  2. Remove the control panel.
  3. Separate the electronic control from the control panel via various clips
  4. Remove the plastic switches from the front of the panel.
  5. Clean switches and both circuit boards with CRC electronic cleaner (or similar)
  6. Carefully resolder EVERY LED connection on the back of the board (pictured above).  I also resoldered some of the switch contacts that looked suspect.
  7. Reassemble dryer.

If successful, you will now have a dryer that turns on when the On button is pressed!

 

 


Whirlpool Duet Washer GHW9400pw4 F06 error code

washer broken girl

My Whirlpool Duet Washer recently started acting up on me.  The washer would start a cycle, however during the cycle, the washer would stop, emit several loud repeated beeps and display F06 on the control panel.  Often, I could unplug the washer, wait an hour or so, and then after restarting the cycle, it would run to completion.  I began to notice that this only would happen during the summer when the temperature in the house was higher than normal.  In addition, it would happen more often when I had a very large load of laundry.

I begin to research what the issue could be.  First I downloaded the Repair Manual and ran the diagnostics.  These always completed successfully.  I than read reports that the MCU (Motor Control Board) can cause this issue.  It would seem that the unit overheats, or has poor solder joints that open when hot.  To test that theory, I removed the lower kick panel and placed a fan in front of the MCU.  I was able to run the washer for several months this way, it turned out to be a good short-term solution, and confirmed that the MCU was the culprit.

Eventually, this trick was no longer successful, and the dreaded F06 error returned.  I was able to buy a replacement MCU, part number W10756692 (also 461970300683) which is used in many Whirlpool Duet Washer models such as the GHW9100lw1 and other Kenmore and Bosch washers.  The retail price is usually around $250 new, but I found a used MCU on Ebay for $50.

whirlpool duet MCU W10756692

Replacement is simple, remove the lower kick panel.  Detach the MCU after unplugging the five electrical connectors, and reassemble with the new MCU.  Always remember to unplug the washer before attempting this repair!

With a new MCU, you should find that your Whirlpool Duet once again works like new.