Saturday, October 31, 2015

Signs And Causes Of An Overheating Computer Or Other Electronic Device

An overheating computer is probably the most common computer problem I have encountered, in several decades of building and repairing them.

Below you can see the new case fan that I installed to replace the one that prompted this article. The old fan had failed and wasn't spinning, and the computer was randomly powering off.



Signs Of Overheating


There are other signs of overheating for electronic devices, but these are the most common in my experience.

1. Your computer or device randomly powers off or reboots. This effect is worse on a warmer day.

2. Your computer or device is unstable with the applications you normally run.

3. You hear more noise than usual from the device's fans.

4. You feel more airflow from your device and/or the airflow is warmer than usual.

Causes Of Overheating


The most common causes I have seen for overheating computers (and electronic devices in general) are:

1. Failed Fan: It could be caked with dust, or the bearings could be worn out, or who knows. If it's not spinning, it's not moving air, and whatever part of your computer it's attached to isn't being cooled properly.

2. Dust in Heatsink: The fan has to be blowing air over the heatsink to be cooling whatever its attached to. Anything that does its cooling with a fan will eventually be caked in dust, and need to be blown out with a can of air. 

3. Improper Air Flow: If the computer or device is sitting in a corner where its fans can't move much air, it's the same effect as the above two problems. Ideally you want your computer in as wide open of a space as you can get it. And if it must be in a confined space, move it back from the wall.

4. Ambient Conditions: Fans and heatsinks use something called "physics" to cool your device's silicon. If their is too much moisture in the air and/or it's too hot, your device can still overheat, even when it is properly functioning. Not much you can do about that except keep indoors with your AC on ... or move.


Saturday, October 24, 2015

How To Fix Magic Chef RV Stove Not Lighting All The Way

This Magic Chef stove in the RV I just got was beyond disgusting. I may have to pull the whole unit just to clean it all the way, but for now I'll settle for the burners lighting properly. The oven won't light correctly, even after a new safety valve, but that's a different project.

The problem was that the individual burners were not lighting all the way around. Half the burner would light, dumping LP gas into the trailer and creating a dangerous and bad smelling situation. I could take a lighter and manually light the part of the burner that wan't lighting, but that's obviously not how the unit was meant to work.

And this is after I thoroughly cleaned it! Notice how grungy the back burners are--they weren't lighting correctly


The solution was to get a wire wheel set for my drill. Putting the wire wheel on all the burners served to unclog the little holes where the gas comes out. I'm no gas stove genius, but it was pretty clear that the smaller holes function to light the larger ones, making the flame work its way around the burner when just part of it is lit. The wire wheel cleaned out the gas holes and also made it look shiny and not disgusting.

Also, there are little holes in each burner that feed gas to the ignition manifold where you can turn the knob and light any one of the burners. I had to damage one of the metal tubes that connects to the burner. So, using the wire wheel to clean the ignition holes also made each burner light more easily.

They look shiny and light properly now

Only 4 hours of scrubbing the stove top and an hour with the wire wheel

These gas feeder tubes for the ignition are telescoping, meaning one smaller tube inside a larger one so it's easy to extend the tube into the burner or pull it out of the way when you're working on the burner. It's a decent design, except the tube to the front burner is seized, making it too short, so it falls off randomly. So, I also sprayed some penetrating catalyst, and I'll come back in a week or so and see if I can extend the front tube. It's funny that it rusted set to its shortest setting, meaning that this oven hasn't worked right in a long time!


Sunday, October 18, 2015

Mark's Troubleshooting Tips: Don't Be A Parts Changer

Mechanic's school was a long time ago for me. I didn't do it for a living for very long, but I still do all my own work for everything: house, car, appliances, etc.

A few things my instructor told me still echo in my brain. He used to say "most mechanics are just parts changers." To reliably fix things, you have to intimately understand how they work. This is easier said than done when you fix a wide variety of things like I do. 20 years ago, if you didn't have the manual or the personal expertise, you had to find someone who did, or guess. Now, through the wonderment of the google-machine, most of the time whatever you want to know is a simple search away.

Obviously there's more guesswork in figuring out something new, like a gas RV oven recently for me. But taking the time to understand how what you are working on works, almost always pays off. Reading the manual, finding out what other people are saying, watching videos, etc., gives you an advantage before you take something apart, or replace a part you didn't need to replace.



Sometimes the time it would take to troubleshoot a part is proportional to the cost of the part. For those times, I have the attitude that if I have to take the part out to check it, I might as well just replace it. But when the parts are expensive and the labor is cheap, you really want to understand intimately why what your trying to fix isn't working.

Sometimes being able to troubleshoot and understand a problem isn't completely possible because you lack some tool or technology to diagnose the problem. Understanding how it works is still helpful, and will let you make a more educated guess.

This is why I am almost always willing to buy whatever specialized tools I need, within reason. For example, the $35 engine code reader has taken the mystery out of dozens of "check engine light" events for myself, friends and family.

Sometimes you want to know for 100% fact that something is perfect. You want to change the parts because you want all the best parts. This is about the only time it's beneficial being a parts changer. No need to check it or troubleshooting something you already intend to replace!

Tuesday, October 13, 2015

How To Replace An RV LP Gas Regulator

In a previous post, I replaced one of the gas lines that was leaking. The other one worked, but it looked dicey. The LP gas regulator also looked dicey. It seemed to work, though it was showing red with both tanks connected instead of showing green like it should've been. So, I decided to replace the regulator just to be on the safe side. To me, "looks shady" and "propane" don't mix.

I got the other "pigtail" gas hose and the regulator on Amazon, but it took a couple extra days for Prime processing (whatever that means) so it came three days behind the pigtail hose, and I waited to have everything at once. I still had my yellow teflon tape from the last job. This tape is beautiful to work with. For the regulator, my Fleetwood Prowler came with the Marshall regulator as OEM equipment, and from reading reviews on the other brands, I came to the conclusion that it was worth paying 51 bucks to have one that wasn't going to fail for a long time.

Above, the old regulator with the one new pigtail hose I had replaced last time

Tools


I used the same two adjustable wrenches from my last post, for all the fittings, as well as a Philips screwdriver to dismount and remount the regulator to the LP tank structure. I also used a pair of scissors to cut the teflon tape. I wanted to use the cordless screwdriver but it would reach, and I don't have an extension for it.

Warning


Working around gas, it should go without saying that you do not want to be near anything that is smoking, on fire or anything that can even make a spark.

Step 1 - Turn Off The Tanks


Make sure to turn off both tanks. This is very important. You do not want to win a Darwin award.

Step 2 - Take Off The Pigtail Hoses


First disconnect both hoses where they screw onto the propane tanks. You can do this with your hands. Next, disconnect the fittings on both pigtails. As you loosen it, the hose can turn because you disconnected from the tank first.

NOTE: A little bit of gas can come out when you disconnect the tank, even with the tank off.

Step 3 - Disconnect The Main Gas Line


If it's easier, you can swap steps 3 and 4. What you want to do is disconnect the main gas line that goes to the regulator so you can take the regulator off. Use the two adjustable wrenches.

Step 4 - Dismount The Regulator


With everything disconnected from it, take the mounting screws off with a Philips screwdriver. Mine only had two screws holding the regulator on. It came off without a fuss. If you are having issues getting the wrenches into the tight space to take the hose off, you can just dismount the regulator before disconnecting that last hose, which is what I did.

Step 6 - Take Fitting Out Of Old Regulator


My new regulator came with the side fittings but not the bottom one, so I had to take it off the old regulator.

Step 6 - Mount The New Regulator


Another reason I got the same brand is because the mounting was the exact same as the old one. Two screws and it was laughably easy.






Step 7 - Connect The Gas Line "Pigtail" Hoses


Connect the fittings first, so the entire pigtail can turn while you are tightening the fittings. Take the old teflon tape off the fittings before putting them back on. I'm not very good at explaining how to do the tape, other than picture how the tape will tighten when you tighten the fitting. If you wind the tape the wrong way, it may not make a good seal. I usually do at least 2 layers pulled fairly tight.

Next, connect the tank ends of the pigtail hoses, but leave the tanks off for now.



Step 8 - Connect The Main Gas Line To RV


Now, I'm not sure if the "pointy" end of the existing fitting gets taped or not, so I taped it. I left the other side un-taped. It look like it originally had loc-tite, which isn't really a sealant.

Step 10 - Turn Both Tanks On


Turn both tanks on all the way. You will hear some of the gas moving into the previously-empty pigtails and regulator for maybe a second or so, but you should hear no hissing sound, which is a different sound. If you hear hissing and small gas, turn both tanks off.

If you have a leak, look for the leak with one tank on at a time. If you don't hear any hissing but still smell gas, then you can use soapy water over all the fittings and look for bubbles.




Step 11 - Inspect Your Work


If both tanks are on and you don't hear any hissing or smell any gas, then you probably did it right. But check everything anyway. What I do is at least grab every fitting and stuff that's supposed to be wrench-tight and making sure it's not finger-tight.

Doing a last second check on this job, I noticed that the main line coming out the bottom of the regulator was finger-loose! I could swear I tightened it good enough! And if it's time wasted because you did everything perfect, you have the piece of mind knowing that every single fitting and hose was double checked.

Step 12 - Test Your Appliances


Before I put the big plastic cover back on my propane tanks, I run inside the RV and check the stove real quick to see that the flame on the stove top looks nice and uniform and is as flamey as it should be. Only then do I go back outside and put the cover back on, and put the tools back.

Other Thoughts


I hear that labor to work on RVs is ridiculous. Everyone says that RVs are a money pit. So far that's true, but it's gratifying to do my own work, and the "pit" hasn't been that big. The new regulator and gas hoses were about $75 from Amazon, and it was only 20 minutes worth of work for such a good piece of mind knowing it's all perfect.




Saturday, October 10, 2015

How To Replace An RV Propane Gas Hose (Pigtail)

"I want to find a fixer-upper where I can do my own work and get a great deal" I said, having never owned an RV before. The first pass was fixing the high priority stuff like the fridge and microwave. Now that the stove top works, making the LP gas system perfect has been the top priority.

The right side hose (pigtail) was cracked and completely unusable, so I had to order a replacement RV pigtail from Amazon. Ten bucks and two days with Prime. I also got the yellow teflon tape to get a nice, tight connection to the regulator, which is next on the list to replace. But for now, I just replaced the pigtail.

This fitting made a "ssssshhhhhhh" sound when I turned on the tank ... NEXT


Tools


Normally I would use two open-end wrenches, but my big toolbox was at my sister's house, so I just used a small and a medium sized adjustable wrench. It's really helpful to have a simple adjustable wrench set, if you don't already.





Step 1 - Remove Tank Cover

This shouldn't require any special tools. Mine has a wingnut that holds the cover on.



Step 2 - Turn Off The Tanks


In a two tank setup like mine, you don't have to turn off the other tank, because the regulator is supposed to use the tank the lever points to, or the other tank if it has pressure, which it won't because you'll turn it off first.

To be on the safe side, it would probably be best to turn both tanks off.

Step 3 - Take Off The Old Pigtail


Disconnect the gas line from the tank, and then use both adjustable wrenches to take the hose off of the fitting that goes into the regulator.



Step 4 - Tape New Pigtail Fitting


Put a couple turns of LP gas rated Teflon tape on the new gas line fitting. Turn the tape with the threads on the fitting, so that when you tighten the fitting, you're tightening the tape and not loosening it. You may have to think about it for a minute or two.

Step 4 - Connect New Pigtail Fitting To Regulator


Using the small adjustable wrench, attach the fitting on the new pigtail. It should be nice and snug, but not tightened to the point that it damages the tape. It's normal to score the tape where the wrench grabs the fitting, but it should be nice and smooth on the threads. If it's not, take off the tape and try again.



Step 5 - Connect Tank Fitting


Connect the other end of the pigtail to your propane tank using just your hands. It should be nice and tight, but if you are a giant moose, then make sure not to over-tighten it.


Step 5 - Turn On Both Tanks


Make sure both tanks are turned on. If you smell gas and/or hear hissing, then brush some soapy water on the fitting(s) to see where it's leaking from. Be very, very careful if you detect a leak.

Step 6 - Check The LP Gas Regulator


At this point, if you have the type of regulator that shows red or green, it should now show green. Mine turned out to still show red, because the regulator is defective. I also bought another pigtail because the left one looked a little shady in the photos. I will do the new pigtail when I do the new regulator, which I just ordered today.

Step 7 - Check Your Appliances


If you don't detect a leak, and your regulator seems OK, then the next step is to check your gas appliances. My stove top now works with both tanks, but the oven needs a gas safety valve--one more thing to replace!

Other Thoughts


Keep in mind that LP gas is highly flammable (which is the point) and potentially explosive. Ask yourself: "Do I want to be a recipient of the Darwin Awards?" I don't. So, don't do anything stupid.