USB PORTS on the motherboard WORST INVENTION EVER.

[krw]

The plan is to charge my friends and associates one dollar per eye for
the test. After 25 such exams, I break even. I've done roughly the
same thing with loaning everything from garden machinery to computers.
Oddly, the $1 charge has dramatically improved my rate for returning
borrowed items over when I was doing it for free.

I guess I'd never consider charging friends. I generally loan them my
old tools (or HF's specifically bought for that purpose).

The PD numbers vary depending on who's doing the testing and what
device was used. In my case, I had it done 3 times at Costco and
twice at two different retail stores trying to sell me their
overpriced glasses. The basic instrument resolution and accuracy is
+/-0.5mm. I had PD totals varying over a 1.0mm range for distance,
and 1.5mm for reading. In one case, I had to explain to the lady at
Costco how to correctly operate the instrument. After buying the
close work glasses that didn't work, I went back to what I considered
to be the most competent retail store and essentially bribed them into
letting me use the pupilometer and extract my own numbers. That's
when I discovered that the sliders had some backlash. I ended up
generating two sets of numbers, coming from both directions, and
averaging the results. The store was very interested in what I was
doing and was quite happy to NOT sell me a pair of glasses as they
correctly assumed I would be an overly demanding customer.

Seems it's not _that_ important, then.

I think they care as nobody appeared to be negligent or intentionally
sloppy, just clueless. My guess(tm) is that they don't realize how
important the PD numbers are for high power glasses. They probably
dispense thousands of low power glasses that are deemed acceptable by
the customer. With higher power glasses, the customer probably
doesn't realize that their prescription could be improved by using a
proper PD. Since returning adult customers are probably not retested
on the pupilometer, once the wrong numbers are inscribed in the files,
they tend to be permanent, leaving the customer with no standards for
comparison.

Seems that would have been covered in their schooling. The ODs I've
used haven't been dummies.

What made me realize that things could be better was borrowing a trial
frame and lens kit for a week:
<http://www.ebay.com/itm/190718288464>
<http://www.ebay.com/itm/190710069079>
After some tinkering, I noticed that these glasses worked better than
my regular prescription glasses. I eventually determined that the
shopping mall optometrist, who decided that my eyes had changed over
the years from the original Kaiser exam and "adjusted" my
prescription, didn't do a very good job. I went to Costco for an eye
exam, and they compounded the error by analyzing my existing
prescription on a lensometer, and using that as a starting point.
That's standard practice and saves considerable time. The result was
very much like the "adjusted" prescription, which was wrong. I
eventually convinced Costco to do a retest, this time starting from
scratch, which resulted in a prescription that was much closer to the
20 year old original, and my tinkering with the trial lens kit.

If you want it done right, either watch the experts carefully, or do
as much as possible thyself. Either way, take some time to understand
how it all works and the processes that are involved.

I guess it would be more important if I were as blind as a bat. ;-) I
think these are only 2.5d in the uppers (the problem seems to be
mainly the astigmatism I picked up). I'd have to get out my
prescription, though.

 

[krw]

I have friends and I have customers. The difference is that the
customers pay me. I'm working on converting non-paying friends into
customers.

I'd never do business with friends. Too easy to lose on both ends.
Friends help friends and don't look for payment, particularly if there
are no direct costs involved. That's the way I was brought up.
Sometimes it doesn't work both ways but that's life too. Live and
learn.

For low power glasses of less than +2.0 diopter, it's not very
important. For higher magnifications, the PD becomes increasingly
more important. I wasn't convinced to I played with the PD using the
trial frame. I couldn't see much difference initially, but after
trying to actually work close up for about 20-30 minutes, I started
having problems focusing. Adjusting the PD to the correct value
reduced the problem and also eliminated some eye strain.

I meant not very important at .5-1mm error range. It's certainly
important. I can really see (NPI) it with the Mantis at work.
Binoculars, as well, obviously.

Incidentally, I found an easy way to measure PD. I taped a steel rule
to my forehead and then took a photograph of my face with a digital
camera. Using software that can count pixels (Windoze Paint), I first
calculated the number of pixels per cm using the ruler on my forehead.
Measuring the number of pixels between pupils and dividing by the
number of pixels per cm yielded what appears to be a fairly accurate
PD. The only things that were critical were keeping the ruler
horizontal (use two piece of tape) and having the camera directly in
front of my face (use a tripod and a remote trigger).

Cool! Neat idea! Maybe I'll try Zenni armed with the above.

Competence and the ability to get it right every time are only loosely
related.

In this case you've noted that they don't think it's important to get
right. Their schooling would have taught them better.

There are plenty of ways to make an otherwise competent
person do dumb things. The first of two Costo optometrists decided
that it was acceptable to maintain a running conversation with a
salesman while doing the test. He was running late and my appointment
apparently cut into his appointment with the salesman. At the end, I
pointed out an obvious mistake in the prescription which he corrected.
To save time, he based his prescription on my then current erroneous
prescription. I suspect that he was well schooled and highly
experienced. However, when pressed for time and distracted, I don't
expect much in the way of quality. The 2nd Costco optometrist was
much better (after I decoded her handwriting).

Different situation.

If you can't find your prescription, you can take the glasses to any
optometrist or optician shop, who will use a lensometer to extract the
prescription. They won't be thrilled with doing it for free, but it's
possible. You should have a copy with you when you travel. A friend
lost her glasses while travelling in Japan. I obtained her
prescription from her optometrist so that she could have a replacement
pair made in Japan (which incidentally was done overnight).

Doesn't it require a prescription in the US. The prescriptions I've
had are dated and no one will take them after a year from that date. I
would presume they wouldn't dispense eye glasses without one. ...and
they want the OD's fee, too.

How to use a Lensometer:
<

>

Interesting. Not that I'll ever find a use for it. ;-)

What the prescription numbers mean:
<http://www.livestrong.com/article/155152-what-do-prescription-numbers-mean-in-eye-glasses/>

Confirms pretty much what I'd presumed from the names and the physics.

 

[rickman]

I also live in an appartment high up, so I am not sure if grounding wall
sockets is a good idea.

What? Why would that be? Are you suggesting that it might attract
lightning? lol

Rick

 

[rickman]

I've used them once and was happy with the results.

I've been wearing bifocals for around a decade, but found them less
than ideal for computer work... too far away for the "near"
correction, not far enough for "distant", and craning my head back to
try to look through the "near" lens was giving me a headache.

Yep, that's why I got a pair with the upper lens set for the computer
and the lower lens set for closer work. The neck/head pain is a well
known result of using the lower lens of bifocals for computer work. I
had it very severely at one point.

I recently had my eyes checked and bifocal prescription updated (and a
new set of bifocals made). I followed Zenni's recommendations for
calculating the correction needed for a set of "intermediate distance"
monofocals, plugged those numbers into the order form, and got the
glasses a couple of weeks later. Vast improvement for computer
work... just about right... eyes are much happier at the end of the
day. I think I'll spend another $50 and get a second set for my home
computer setup.

Zenni never asked to see the original prescription... as far as I can
tell, you can plug any set of numbers you want into the order form and
they'll make it for you.

That is encouraging. A friend has trouble with his glasses, I'll talk
to him about this, but he isn't likely to know how to modify the
prescription to suit him better.

Rick

 

[rickman]

Probably yes, but they aren't asking for the original prescription or
any optometrist identification information. Apparently, nothing is
going to happen until someone complains. Like many of our medical
related restrictions allegedly designed to protect the GUM (great
unwashed masses) from alternative medicine, the 2 year requirement
creates an almost captive market for optometrists and opticians at
inflated prices. My last pair of bifocals from Zenni Optical cost me
about $40. My last pair of single vision glasses from Costco cost me
$280.

I don't get the $280 price tag. I got bifocals for $100. Even the
ripoff places would have trouble charging you $280 for single vision
glasses.

I also repair HP LaserJet printers. I don't make much money on the
repairs, but for some unspecified personality defect, I enjoy fixing
them. I go through quite a few office printers. Mostly, I sell or
loan them to customers and obtain a different printer. The local
eWaste recycler is a great source of laser printers. Rebuild kits and
cheap toner is commonly available on eBay. I've made it my personal
crusade to consign all inkjet printers to the recyclers, and replace
them with cheaper to operate, more reliable, and infinitely faster,
laser printers.

I'm not sure what printer you saw, but my current favorite is the
HP2300dtn. The previous incantation, the HP2200dn had some issues:
<http://802.11junk.com/jeffl/hp2200/hp2200.html>

I just checked and it was an 1100. It works just fine, I just have to
feed each sheet one at a time.

Rubber separator pads do wear out. Cork pads seem to last longer. My
guess is that they both will last about 75,000 to 100,000 pages. I
have various potions (xylene rubber restorer) which will soften the
rubber, but once it wears down below the level of the plastic mounting
frame, it's over. Replacements are commonly available from
Printerworks.com and eBay. Good advice on printer repair from Moe at:
<http://www.FixYourOwnPrinter.com>

This was a design defect. I likely didn't print 1000 pages in the first
year. I just didn't realize it was the printer rather than humidity or
the paper. It took me some 8 years to run the toner out of the original
cartridge, then the no-name replacement I got had a flaw in the roller
and puts a star every couple of inches on each page. This was in the
days when many vendors on eBay had high shipping fees and low prices to
discourage returns... it worked. Not a big deal, I just don't print
much, mainly a very few formal letters and envelopes for tax payments.

No. I need the model number. The only HP laserjet that has a bolt on
scanner on the front is the HP1000/1100/1200/1300 series. I had a few
of those in the shop for repair and rebuilding, but none had the
scanner option installed. It's an ugly little printer, that has a
nasty habit of attempting to feed the entire stack of paper at once
when the separation pad wears out. Replace the separation pads and
associated rubber parts
<http://www.ebay.com/itm/121014298023>
or buy a paper-jam fix kit. I haven't had much luck with the fix kit.
None seem to be available on eBay.

I'll take a look at the repair kit. Does that last longer than the
original?

I think you might mean VHF, not VLF. I have plenty of those, but
they're all products that I designed in the distant past. I want to
keep them. They're also not exactly state of the art. Get something
that floats for the inevitable roll. I'm not up to date on the latest
marine handhelds and can't recommend anything specific.

Yeah, VHF. I'm working on a LF receiver and get my abbreviations mixed
up.. lol. It's funny how kayakers all have very different ideas on what
is the "right" stuff to use. Many different paddles, many different
boats, etc. I think mostly they like whatever they have once they've
bit the bullet and bought something. I don't know anyone who doesn't
recommend the unit he has. Some don't like the floating units because
they are larger. Once you are in a kayak and suited up with all the
gear, every little piece of equipment makes a difference. Try getting
back into your boat with a brick strapped to your chest. They prefer
the radio is small enough to fit in a PDF pocket.

I saw your WWVH question in rec.radio.amateur.antenna but never had
time or interest to go beyond my few bad guesses. Building one of the
numerous loop antenna construction articles might be best.

Yeah, I bit the bullet and ordered some RG-6 coax today. I wanted to
figure out "properly" what type of cable would be best, but I'm not
making much headway on nailing down the calculations on a loop antenna.

I've done a bit of antenna design and modeling. However, NDA's and
contracts prevent me from posting or discussing the interesting
designs. Here's the bottom of the barrel.
<http://802.11junk.com/jeffl/antennas/>
Only a few are my designs or ever went beyond an NEC2 model. Mostly
they're on my web pile to settle some manner of online argument.

I'm writing this offline. I'll try to remember to look at the link when
I am back online.

Rick

 

[Chris S.]

I didn't touch the PC when the buzz sound occured.

I suspect the USB Plug misalignment caused the buzz sound on the DreamPC.

The same buzz sound happened on the Pentium III 450 mhz when one of those
power connectors/hd leds/power switch connectors was wrongly connected I
think.

The real question is:

What would have happened if the PC was grounded ?

Would the misplaced USB plug go undetected ?

Would it have prevented damage ?

In a way maybe it was a good thing the PC was not grounded, at least I
heard literally that there was a problem.

Unfortunately it did cause damage.

If it didn't then the usb drive/card reader probably wouldn't have worked
and I would have found the misaligned plug eventually.

I also live in an appartment high up, so I am not sure if grounding wall
sockets is a good idea.

I have explored this topic in the past...

I don't want to change the wall socket because I don't know if that's
safe... I don't like changing things which have worked for tens of years
for other people...

For all I know it might make matters worse and there is definetly some
thruth to that...

Bye,
Skybuck.

How can one man be SO wrong EVERY time? Incredible.

Chris

 

[Skybuck Flying]

I think we've found your (real) problem. Use a socket with those grounding
brackets, not one for electric shavers/hairdryers. The buzz you hear from
your soundcard is the line frequency(50 Hz). The case is a big capacitor
and may charge up to line voltage. You cannot expect the thing to suffer
repeated discharges(when you touch it) and continue working.

I think I just noticed this buzzing again... while trying to plug in an
audio cable while everything was on.

I shall try and contact the building owner, and try again to get these wall
sockets grounded.

Though one powersupply of the old computer popped and the circuit breaker
went off... don't know why...

I thought at the time maybe drawing too much watts from the electrical
system... perhaps over 1800 watts...

But could also have been a short circuit...

I did notice a little bit when touching the pc case and plugging in the
audio cable at the same time or nearly same time... that this buzzing
occurs... not entirely sure...

It literaly sounds dangerous though.

However I am still pretty sure that misconnecting the usb plug also caused
damage.

So many ways/dangerous ways to cause damage or die...

So I will try to at least prevent deaths from happening

Though as Chris S didn't understand... "any change introduces the
possibility of mistakes made"...

So having somebody work on the electrical system is dangerous if that person
doesn't know what he's doing or simply makes a mistake becaue he's human.

Though having experienced a power supply failing is somewhat worrieing.

Bye,
Skybuck.

 

[Skybuck Flying]

What? Why would that be? Are you suggesting that it might attract
lightning? lol

Rick

Aduio/Ground Loops. Google it.

 

[Skybuck Flying]

How can one man be SO wrong EVERY time? Incredible.

Chris

How can human beings make so many mistakes ?

Bugger off.

 

[Skybuck Flying]

I think we've found your (real) problem. Use a socket with those grounding
brackets, not one for electric shavers/hairdryers. The buzz you hear from
your soundcard is the line frequency(50 Hz). The case is a big capacitor
and may charge up to line voltage. You cannot expect the thing to suffer
repeated discharges(when you touch it) and continue working.

Something doesn't add up about your theory though.

So far:

1. The PC case has 110 volts on it, but very little ampere ?!

Now you claim that when I touch the PC case and touch other parts of the PC
and/or audio cables that this will somehow give a shock to the PC equipment
?

Since there is very little to no ampere flowing how could this be ?

Bye,
Skybuck.

 

[Skybuck Flying]

I think I just noticed this buzzing again... while trying to plug in an
audio cable while everything was on.

I shall try and contact the building owner, and try again to get these
wall sockets grounded.

Though one powersupply of the old computer popped and the circuit breaker
went off... don't know why...

I thought at the time maybe drawing too much watts from the electrical
system... perhaps over 1800 watts...

But could also have been a short circuit...

I did notice a little bit when touching the pc case and plugging in the
audio cable at the same time or nearly same time... that this buzzing
occurs... not entirely sure...

It literaly sounds dangerous though.

However I am still pretty sure that misconnecting the usb plug also caused
damage.

So many ways/dangerous ways to cause damage or die...

So I will try to at least prevent deaths from happening

Though as Chris S didn't understand... "any change introduces the
possibility of mistakes made"...

So having somebody work on the electrical system is dangerous if that
person doesn't know what he's doing or simply makes a mistake becaue he's
human.

Though having experienced a power supply failing is somewhat worrieing.

Bye,
Skybuck.

Hmm.. Ok, I think I get it a little bit...

He said "capacitator" so that's like a battery.

The entire case/plates start functioning as a battery...

The case starts accumilating electrons...

And then when I touch it... those can escape and go back into the system or
so...

Bye,
Skybuck.

 

[Skybuck Flying]

Also explain to me why the kitchen wall sockets are grounded and the living
room sockets are not grounded ?!

Seems very weird to me...

Perhaps there was a good reason for this.

Just telling people to ground everything seems foolish at best because of
ground loops and the way electricity goes to ground.

If people in between that path they might still get fryed... ?!

Perhaps it was to save a few bucks here and there... but I dont believe
that.

Bye,
Skybuck.

 

[Rodney Pont]

Note: I've had a triple bypass heart operation and am therefore
immune to electrocution by current through the heart. Unfortunately,
a silver spike or silver bullet through the heart still works, so I
still have to be careful.

What about an Oak stake? I bet that will work

 

[Skybuck Flying]

SO is your 110V AC socket (in Hong Kong, it's 220V) ? You could short it
easily as well!

No it's 220V in Netherlands, half of that is on the PC case they say, so 110
volts !

Bye,
Skybuck.

 

[Skybuck Flying]

I may have been reading something wrongly but if the grounding is what you
think is causing the buzzing could you not setup the system in the kitchen
to see if it makes a difference? or run an extension lead?

Pete

Yeah but it doesn't reach fully, I could daisy chain some to see if that
works.

Maybe I ll buy an extension cord long enough.

Today was another weird day electronics wise.

I had to pull out all cables.

The monitor did not want to turn off.

The old PC also didn't boot.

It does this each time but this time it was worth.

What happens is:

1. I turn it on, but nothing happens.
2. I turn it off.
3. I turn it on again and the PC goes into the BIOS stating that CPUs
setting was wrong.

I tried setting volts for cpu to 2.00, 2.05, 2.10 but that didnt help.

Really strange how it doesn't want to boot up the first time.

Bye,
Skybuck.

 

[Pete]

Also explain to me why the kitchen wall sockets are grounded and the living
room sockets are not grounded ?!

Seems very weird to me...

Perhaps there was a good reason for this.

Just telling people to ground everything seems foolish at best because of
ground loops and the way electricity goes to ground.

If people in between that path they might still get fryed... ?!

Perhaps it was to save a few bucks here and there... but I dont believe
that.

Bye,
Skybuck.

I may have been reading something wrongly but if the grounding is what
you think is causing the buzzing could you not setup the system in the
kitchen to see if it makes a difference? or run an extension lead?

Pete

 

[Man-wai Chang]

THE USB PORTS ARE DESIGNED SO RETARDLY that it is actually possible to

connect the USB PLUGS wrongly very easily !!!

SO is your 110V AC socket (in Hong Kong, it's 220V) ? You could short it
easily as well!


--
@~@ Remain silent. Nothing from soldiers and magicians is real!
/ v \ Simplicity is Beauty! May the Force and farces be with you!
/( _ )\ (Fedora 17 i686) Linux 3.6.7-4.fc17.i686
^ ^ 14:45:01 up 2 days 3:03 0 users load average: 0.00 0.01 0.05
ä¸å€Ÿè²¸! ä¸è©é¨™! ä¸æ´äº¤! ä¸æ‰“交! ä¸æ‰“劫! ä¸è‡ªæ®º! è«‹è€ƒæ…®ç¶œæ´ (CSSA):
http://www.swd.gov.hk/tc/index/site_pubsvc/page_socsecu/sub_addressesa

 

[Johann Klammer]

I may have been reading something wrongly but if the grounding is what
you think is causing the buzzing could you not setup the system in the
kitchen to see if it makes a difference? or run an extension lead?

Pete

Be careful if you use a satellite dish with twin LNB, no grounding bloc,
computer connected to one output, TV/STB connected to the other one. I
seem to have killed one DVB card that way once.

 

[Spehro Pefhany]

Dunno. In the USofA, most everything is 3 wires, one of which is
protective ground. There are still plenty of 2 wire systems, with no
protective ground still in use. If you look hard, you'll also find
ancient tube and socket wiring. Maybe your house is old?

Isn't Skybuckaroo in the Netherlands?

Maybe the kitchen was renovated at some point and the older style
ungrounded outlets were replaced with the Schuko grounded type.

Blowing up the USB port could be an indication of something more
dangerous. I would have someone with electrical wiring experience
give your wiring an inspection.

Normally, this being a design group, I'd suggest poking around with a
multimeter, but your suggestion is conservative and probably correct
in this case.

 

[Paul]

Yeah but it doesn't reach fully, I could daisy chain some to see if that
works.

Maybe I ll buy an extension cord long enough.

Today was another weird day electronics wise.

I had to pull out all cables.

The monitor did not want to turn off.

The old PC also didn't boot.

It does this each time but this time it was worth.

What happens is:

1. I turn it on, but nothing happens.
2. I turn it off.
3. I turn it on again and the PC goes into the BIOS stating that CPUs
setting was wrong.

I tried setting volts for cpu to 2.00, 2.05, 2.10 but that didnt help.

Really strange how it doesn't want to boot up the first time.

Bye,
Skybuck.

Try a Port 80 PCI diagnostic card.
Cheapest source is "Hong Kong via Ebay". A local
computer store may charge $100 for one. Also, some
motherboards have this two digit display, soldered to
the motherboard surface.

In this example, the two digit display is in the lower left
hand corner of the motherboard.

http://www.pcstats.com/articleimages/200701/Epox5P945Pro_full.jpg

The numbers on the display don't mean anything, but seeing the
sequence of updates tells you the processor is alive and running.

The final 0xFF value typically means "Now booting". When the OS
starts to boot, the BIOS should no longer be in control. If the
display stays stuck at some value, and never changes after the
power is turned on, then the processor is crashed or not present.

*******

You can also get DDR400 memory with LEDs on top. The LED activity
is related to continuous accesses to the DIMM. IF all access to the
DIMMs stop, the LEDs stop flashing, and that's a hint the processor
is actually crashed. So that's a way, once the OS is running, to detect
a crash.

http://www.dansdata.com/images/newnewbox/ramrunning1024.jpg

Paul