Entropy

Relax in southern comfort on the east bank of the Mississippi. You're just around the corner from Beale Street and Sun Records. Watch the ducks, throw back a few and tell us what's on your mind.
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JR.
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Re: Entropy

Post by JR. »

billshurv wrote: Wed Aug 28, 2019 9:36 am like the old man and the leaky roof. 'When its raining its too wet to fix it, and when it's dry its as good as anymans house'
Similar story, when patching my old black asphalt roof, my dumbass neighbor said not to do it in morning when the roof is still damp. I was dumb enough to believe him and by mid day the roof was so hot it burned my butt through my pants.

I'm liking my new tin roof (that does not leak)... the light color helped me get an electric bill 15% lower than the same month last summer despite heat advisories this year. (The new high efficiency 2-ton heat pump didn't hurt).

JR
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billshurv
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Re: Entropy

Post by billshurv »

Sigh. Sat the kids down to watch a DVD this afternoon and, 2 minutes in got a 'no signal' message displaying on the screen. Thought that the DVD player was dead so left it an checked by plugging a laptop in this evening. Nope it's the TV. Ar5e. Quick check on line suggests a known issue, part thermal management on the HDMI receiver chip and part the curse of lead free solder. Lacking a hot air rework station and not wanting to do the usual bodge with the 2kW heat gun I do have going to be a delicate resoldering of the QFP. Not a job I was expecting to need to do over the weekend....
billshurv
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Re: Entropy

Post by billshurv »

HDMI inputs are working again, and I've put a hot air station on my xmas list. Ham fisted oaf I am I did manage to solder 2 pins together on the QFP and took an age to clean them up again. There are certain things you don't use very often then realise why you really need them!
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mediatechnology
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Re: Entropy

Post by mediatechnology »

Nice work resoldering that QFP.
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JR.
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Re: Entropy

Post by JR. »

Solder wick is your friend to remove bridges. I've done my share with old school iron before getting hot air.

I am on my second <$100 chinese hot air station, and might buy another...if/when this one craps out. They keep getting cheaper and cheaper.

JR

PS: My current computer monitor, was my living room TV before I replaced it with bigger/cheaper/LCD, so it is long in the tooth, but large enough i can almost put down my glasses. It has one toasted pixel (always on) and lately the HDMI from my mac is getting a little balky... but it eventually resolves. Not sure I will bother to fix this when it finally stops.
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billshurv
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Re: Entropy

Post by billshurv »

Troubles come in threes. So the tumble dryer door latch has broken. At least that's only £25 and 2 screws to replace.

What will be #3?
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JR.
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Re: Entropy

Post by JR. »

I feel bad about taking credit for a few recent repairs but that's how it goes sometimes.

#1- The power cord for my decades old radar detector stopped locking in the mating connector. This looked just like a phone connector and guess what? a phone cord works.... That suggests to me good engineering foresight to use a commonly available connector... not much fear of somebody plugging a phone handset into the car cigarette lighter. (will future cars still have those? :lol: ).

#2... I have been wrestling with my DSL service for years over this...the bad news is if I call the help line while on hold the crappy intermittent DSL phone service disconnects me... happened once and I stopped trying (I value my time and ran out of patience.. the internet works enough to make this not that critical). Well over a year ago (maybe two) the wifi link to the DirectTV receiver stopped working. When complaining to ATT and/or Direct TV I get the finger pointing dance.. As each deflects blame to the other (even though owned by same company now).

I finally broke down and hardwired my receiver to my local network and all it does is push ads at me when paused (right now its pushing a cinemax ad).Last summer while I had direct Tv technicians moving the dish off my roof, so the roofer could put up the new tin roof, I dragged the tech inside to check my wifi... he confirmed that he couldn't lock to the wifi either.

The WWW is full of customer complaints about that particular POS DSL modem (NVG510). I looked and they are no longer in production so I couldn't buy one new if i tried (I tried). I took a chance on buying one used, and for now the used unit is working.. I now have the receiver locked to my wifi and all is good with that world. So far my internet or phones have not dropped out but it's only been one day.

#3 For the last several months I have been trying to correct a weird running issue with my 22 YO car... Arguably I should probably just replace it, that would be easy... but I like to think of myself as knowing a little about cars.

The first symptom I pursued was apparent lean (not enough fuel) when cold... My first attempt, and harder than it should have been was to replace the secondary temp sending unit (the engine has two, one on each head). The dashboard temp gauge was OK, so my theory was the temp sending unit feeding the ECU was faulty. After difficulty and buying new tools to execute, the problem was not resolved.

The next effort was to replace the fuel pressure regulator.... My car has a fuel pressure regulator to send constant pressure to the injectors and a bypass return line back to the fuel tank. Replacing this seemed to make a small improvement but alas was not it. I had refined my characterization of the symptom... it appears fuel starved when first started, but after ten minutes or so, starts working normally. This is well after engine comes up to temperature.

Next for general principles, I replaced the fuel filter... more drama than it should be, but at my age, getting down on the ground and crawling around under my car involves drama, with a healthy dose of raw gas. No love... and those youtube videos showing how easy it is, are often inaccurate.

My neighbor had been bugging me to spray clean the MAF sensor...He gave me a can of spray cleaner to use. I resisted until this week, and in a pleasant surprise it made an improvement. To properly clean it fully I need to remove it, and is attached with security torx head bolts... The standard torx sockets I bought don't fit... I can remove the entire housing the MAF is in and spray it on my driveway.. I didn't want to spray too much inside while still attached to my intake.

After the fact aided by the crystal clarity of knowing the MAF sensor was involved, it almost makes sense. The MAF sensor uses a hot wire that is cooled by air flow to gauge intake air volume and temperature, by how much current it needs to apply to the hot wire to maintain constant temperature... My new theory is that wire was contaminated, perhaps with some dirt that accumulated moisture (we have humidity here). After the ten minutes or so, the hot wire burns off the moisture and runs normal... or not.

I am also replacing my spark plugs (parts on order) and air filter, both past due.... but my car is now much better. When I stepped on it yesterday, it seemed faster than I remember.

I have more, but that is enough for now...

JR
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billshurv
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Re: Entropy

Post by billshurv »

Ref MAF sensors I had all sorts of trouble on my last car (diesel Passat). Great car, esp after a minor ECU tweak but as I kept it to 290k miles it did sometimes have a few gremlins. The problem was the car suddenly going into limp home mode. Now this could be embarassing if you'd just pulled into the outside lane on the motorway and then lost all boost. turn it off an on again sometimes worked to clear it. After 9 months of cleaning the MAF every few weeks gave up and put a new one in (hey excuse to buy a new set of torx bits) and was fine for a few weeks. Then came back. I then discovered that 2 other sensors can cause the issue. I assumed they were hidden in the belly of the beast so held of getting them until I couldn't hack it any more. Took the front off the car only to find the sensors were in fact both easily accessible on top of the engine...

You might also want to check the idle bleed valve as that can crud up and cause oddities, although normally a rough idle when cold is a give away.
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mediatechnology
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Re: Entropy

Post by mediatechnology »

My neighbor had been bugging me to spray clean the MAF sensor...He gave me a can of spray cleaner to use. I resisted until this week, and in a pleasant surprise it made an improvement. To properly clean it fully I need to remove it, and is attached with security torx head bolts... The standard torx sockets I bought don't fit... I can remove the entire housing the MAF is in and spray it on my driveway.. I didn't want to spray too much inside while still attached to my intake.

After the fact aided by the crystal clarity of knowing the MAF sensor was involved, it almost makes sense. The MAF sensor uses a hot wire that is cooled by air flow to gauge intake air volume and temperature, by how much current it needs to apply to the hot wire to maintain constant temperature... My new theory is that wire was contaminated, perhaps with some dirt that accumulated moisture (we have humidity here). After the ten minutes or so, the hot wire burns off the moisture and runs normal... or not.
I've found very small almost invisible spider webs (and spiders) in MAFs before.
Evicting the spider did make a difference.
Dust can also build up on the hot wire or Venturi tube.
billshurv
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Re: Entropy

Post by billshurv »

amazingly the HDMI inputs are holding. Children are happy.
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