Today I got ASUS M6N laptop for repair. It did not want to turn on and also it does not give any sign that it’s charging the battery.
Laptop was previously sent by it's owner to ASUS repair center and paid 70 EUR only for diagnostics. ASUS came up with 600 EUR bill for repair so owner did not accepted the offer. They suggested motherboard and HDD replacement (?!). I did not understand why HDD because HDD works just great.
Anyway, laptop finished at my place and after 1.5h work laptop is working again! It needed some dust cleaning and bit soldering...
First I had to find disassembly or service manual. Bit of Googling and visiting some favorite sites I found the manual here
After laptop is taken apart I made these pictures (click on image for high resolution):
CPU and surrounding covered with dust.
Loose broken power plug and very dirty fan
Again broken plug after I have "shaked" the laptop a bit. Now you can also see the rest of the power connector.
Bigger picture of the open case and power connector location
Here is the "guilty" part
Which came out from here... Good luck that motherbord and othr parts are not affected with accident
After operation it looks like this. Metal part is soldered properly to the motherboard.
I have melted together top part of the connector case to assure better joint.
As you can see everything is clean and neat again.
It is hard to select a good LCD screen based on the specifications such as
viewing angle and contrast, since different manufacturers have different
opinions on how to measure these. I made these test patterns in order to check
out a few monitors in the shops before I purchased one. You can check the images
on this webpage or put them on a usb stick and try them in the computer store
like I did. If you are already stuck with your monitor, you can use this page to
adjust its contrast and brightness settings, or to show off how good (or bad)
your monitor is compared to those of your friends. With these test images are
much more revealing regarding monitor shortcomings than ordinary photographs and you can judge the monitor quality by eye.
Ctrl-Alt-Up - right side up
Ctrl-Alt-Right - 90 degrees
Ctrl-Alt-Down - 180 degrees
Ctrl-Alt-Left - 270 degrees(If that doesn’t work, try Ctrl-Shift-R)
1. The use of a multimeter is a declaration that the person has no idea of what they are dealing with. Multimeters sample at their designed rate and display an average which completely masks the underlying reality of wildly shifting loads. (If this were not the case, multimeters would have a blur for their least significant digits.)
2. Voltage is EVERYTHING. The current don't flow 'til the voltage says go. Current is merely the result of a voltage differential and is limited by the resistance to it.
3. The 'resistance' (readers please note the quotes before madly posting that there is more than simple dc resistance in play) presented to each rail of the PSU is a maelstrom of shifting values. One moment just a tad, at another, a gargantuan jump. It is to this nightmare that the PSU must react. Testing with static loads is a joke.
4. The specs for PSUs are NOT expressed as 'averages' - if your voltages show a sag, you're 'near the edge', if not 'in deep doodoo'! If the voltage(s) spike/sag outside the limits, ALL BETS ARE OFF.
5. PSUs are mostly 'snake oil' - sold to the indifferent and the gullible (not to mention the adamantly ignorant). I remain convinced that a 'cheap' PSU costs $2.95 to manufacture while a 'quality' unit costs $4.95; the rest is packaging, transportation, advertising and mark-up, mark-up and more mark-up.
6. The 'rating' of a PSU is pretty well WHATEVER the vendor wants it to be; they're the ones who set the parameters for the derivation. (I remember some 30-odd years ago reading an article showing how a stereo amplifier that had true specs of 5W/channel, 20-20K +/- 0.5%, THD/IMD under 1.0% could be advertised as a 200W/channel unit - LEGALLY!) The soul bragging about his 650W Q-Tec has yet to discover that it is 'rated' in peak (transient) power, not continuous (where it would be lucky to hit 425W) and that that particular brand has garnered such a bad rep that it has been abandoned.
7. PSUs are made with 'industrial' grade components (+/- 20%). The actual capacity of an assembled unit will fall in a classic bell-shaped pattern. The bean-counters are the ones who decide the 'most profitable point' between 'returns' and 'reputation'. (Anyone still believe ANTECs are 'built like tanks'? There was a time...)
8. The 'average' system draws less than 200W from the wall socket. Those who cannot grasp the difference between 'average' at the wall and instantaneous 'peak' (all rails SIMULTANEOUSLY) at the PSU output will continue to live on their 'luck of the draw', convinced that a 450W unit can run anything.
I doubt I will ever see a PSU evaluation that actually 'tests' the PSU's ability to maintain voltages within spec (down to the microsecond, or at least millisecond) while each rail was being jumped (both up and down) by 1,2,3...max amps from each possible point (1, 2, 3...max amps), SIMULTANEOUSLY at RANDOM rates. But then, I doubt there is a PSU that could pass.
And considering that component manufacturers are no more forthcoming in their actual peak demands, it probably doesn't matter.
Complete disclaimer text is available
A. Boros ©