Inside a Hard Drive

What Is a HDD :Well HDD Is a Computer Part In which Using Using a Disc Platter Assembly The Information is coded On The Media On the Platter By the head ,the head send out signals and the info is recorded on the media ,The media is megnatic in nature .We all use hdd of different sizes and performance levels and Interfaces .

Parts of the HDD :

• MHA Assembly :Metal Head Asembly ,This is Also Know As head and platter assembly ,This is the Part that Contains The Motor ,The Platters ,the Head And The entire Iron Cage With The Top Cover Thats Air Sealed "Actually Air does Flow into the HDD Chamber ,More About This Later On ".
• PCB Plate :This is Called The Printed Circuit Board ,this Contains The Main Processor ,The EPROM ,RAM And The Motor And Spindle Controller .This Also Has a Protection Circuit for Protection of surges In The 12 And 5 Volt Electrical Line .

Explanation of the Parts :

• PCB Plate :Parts of The PCB Plate

  • Main Processor :This Processor is made my many different electronic Manufacturers Like ST Micro And All ,Mostly they Are Specifically Made Processor For Different HDD Manufacturers And Are any Models even For One HDD Manufacturer .This Processor contains The Software code that Makes the HDD Work I Mean Its The code Or The Operating systems That starts As Soon As the PCB And The HDD Recieves Power ,If You Find That Your HDD Is Totally Dead That Might be due To the Fact That the Crystal That Gives Clock Signal to The Main Processor is Dead ,Try To check That With a Scope or a Multimeter With Frequency Measurement .
  • EPROM :This Contains The code That Is In Addition To the Microcontroller "Main Processor " Code ,Some HDD Microcontrollers Do Not Have Enough Space For The Code ,So The HDD Manufacturers Put Additional Code Int the Serial Or Parallel EPROM On The PCB . Once the Microcontroller Processes All Its Firmware akka operating code It Send a Jump Instruction To The EPROM And The EPROM starts Executing Its Code .The Probability Of the EPROM Code Getting Damaged In The PCB is Very Very High ,You Could Take Out This EPROM And Program It With the Same Firmware Version Or Alternatively You Could Connect the PCb to The Serial Port on the Computer and then program the same ,Yes The PCB also Has a Serial Port ,More About That Later On.
  • Ram :this IC Is Also There On The PCB and Its As RAm In Our Desktop Computers ,This Could also Get Damaged And Could Require Replacement .This Also Can Be checked And Replaced If Found Defective ,A Defective RAm Ic Will process everything with erros in the pcb .
  • Spindle Contor Controller :This Ic controls the Speed of the Spindle Motor In The HDD ,a Defective Spindle Motor Is a Rather common Issue ,Most Commonly this Chip just blows away Due To The Fact That the Spindle Motor Gets a Coil Short Circuit .
  • Preamp Control Chip :This Ic Is Present In Some Drives And In Some Its In The Spindle Motor Controller or The Main Microcontroller .The Purpose of This Is To Send The signal To The Ic Called The Preamp Control IC inside The Head And Platter Assembly Unit ,The Preamp Ic Amplifies That And Send To The Head And Visa Versa .Damage To This Is Also Very Common ,But Prior to Replacement of This You Should Make sure That the Preamp Ic Is Still Working Or If The Preamp ic Is Gine This IC Replaced Will Become Toast again .
  • Protection Components And Parts :These Parts Helps To Keep The Voltage of The PCB At Acceptable Levels for The different IC And Some Of The Parts Are Used For Protection Too .

• MHA Assembly :Parts of The MHA Assembly

  • Motor :The Platters Are Mounted On This .This Makes The Drive Spin ,This Is a Stepper Motor And Controlled By The Stepper Motor controller From The PCB .Common Issues Are that the the Coils Of the Motor Can Get Short circuit And the Same Needs Replacement ,But This Requires a Clean Room Environment And specialized Tools To Take The Platter Out And Then The Motor Out And The Replace The Same .Best Way Is to Test The Coils of The Motor By a Multimeter or a Mircometer .
  • Platter :This is The Actual Megnatic Round Plate That Spins And has a Megnatic coating ,All the Info is Stored And Read By the Head on This ,Common Issues With This Are When a Head suffers a bang with the platter due to shock or any other issue .This Creates a permanent bad sector into the surface or damages the surface .Once this Item Suffers damage ,No person or data recovery company can recover the data.All Platters Have Servo information Written Into Them,This is Done By Servo Writers that The HDD Manufacturers Have .If the Servo information is lost on the platter the head does not come to know where it is positioned And The Drive Becomes Junk .
  • Head And Preamp :The Long Needle Type Thing In The HDD Has a small Item in The End of It Now Thats the Head ,There is also a Ic that is connected In This This Is Called the Premplifier ,This Preamplifier Amplifies the Weak signals When the Head Reads and also send the signals to the head for writing on the media .More Power is Required To Write Then To Read the Megnatic Media on the Platter .
  • Other Parts :Other Parts Are the Area where The Head Rests when The Drive Spins Down ,Mostly It Rests on the Platter Itself "There is Dedicated space Into The Platter for This " .There Are Also Air Filters Inside The MHA Assembly .Air Is Required for The Heads To Float on The Platter ,Thats The Reason All HDD Have a Small Hole On The Top Cover With Instructions "Do Not Cover This Hole " .
    

How It works

• The HDD starting Process :As Soon As We Switch On the HDD the HDD Main IC Or the Main Microcontroller starts executing the code inside it .This Ic Uses the Ram Ic for Temp Storage of the Code .Then The Microcontroller searches for External Code In The EPROM "If There Is Any" .If a EPROM is Found the Microcontroller passes the control of processing the firmware code to the EPROM ,the EPROM then starts Executing The Code inside It and USes The Mcrocontroller And The RAm Ic To support This .Now This is The Most Interesting Part Which thousands Of People Do not Know ,I would Say such Information is Highly classified But Here i Present It To TE Members.The EPROM Has a Head Map That Specifies That In The Perticular drive in action the main active head is what "Head 0 or 1 or 2 or 3 etc " .The The Control Is Passed To the Code Inside the Platter On The Mai Active Head ,Yes Mates the Platter Has The Code For The HDD Firmware Too .The code On the Platter Can Contain Two Parts the App Code and The Modules ,The App Code Akka application code Is something Like the Code in The Microcontroller And The EPROM .The Modules Are Small Collections of Data that Stores Critical HDD Information Like Glist And Plist ,The Smart Data Modules And Other Critical Modules .Once The Control Is In the Hands of The App Code It Reads the HDD Modules On The Platter and Then Passes This Information To The Executing Code ,Once This is Done The HDD Gets On Track And starts Working .So The Moral of the Fact Is That Is The HDD Cannot Read the App Code And The Modules On the Platter It Can Never Work
• More Info about Code On the Platter :Only 1 In thousands will Know That the HDD Has a Lot Of Information Other then your Data .There Are Sectors That Go n Reverse Means If The Sectors Starts From 0 Like 1,2,3,4,5 These Sectors Are Actually 0 and Minus Means -1,-2,-3 ,-4 etc .These Sectors Can Not Be Accessed By Any Software and Require Special Hardware And Techniques .Data That Make the HDD Run Are Stored On These Sectors .This Can Comprise Of Code Like ATA Code ,More Firmware And Modules .I Will Explain You all Of these In Great Depth Now .
  

  • Firmware Code On These Sectors : Mostly the Micro controller Is Same In Many Many PCB's Plates So How Does The Manufacturer Make Different HD Family Different ,Well First If The MCU Is Same For Many Families It Uses The EPROM To Store More Firmware "Operating System" Code As Explained Earlier .And If The EPROM Is Not sufficient for Storing This ,Then The Manufacturer Uses The Space In These Reverse Sectors Of The Platter ,I Hope i Was Clear In This
  • ATA Layer code :This Code in The Reverse Sectors Contains the code to Process ATA Commands ,This Layer In Mostly Present In Seagate and Few Other Drives .If This Layer Is Not Present in the Drive It Cannot Process The ATA Commands From the Motherboard IDE Port .
  • Modules :One Of The Most difficult And The Most Interesting Sectors in the Reverse Sector Area Of The Platter .The Modules Are further Divided Into Into Many Type Like Essential Modules ,Unique Modules "That Are Unique To That HDD " ,Non Essential Modules ,Logs Etc .The Essential Modules are must for the drive operation .The Other Modules essential for operation are The Unique Modules .Lets Discuss Some Of the Ultra Essential Modules

    • Glist Module :This is Called The Growing Bad Sector List ,This G List Can Get Filled By software Utilities Made To Remove Bad Sectors "Mark Them and Hide From the Operating system Like Windows" .The firmware Also From Time Automatically Keeps Adding Weak And Other Bad Sectors to the G-List .If the Glist Module Gets Full There Is No Way To Mark Bad Sectors ,Then Using specialized Hardware Either You Ned To empty the Glist Or You Ned To Move The Glist To the Plist "More About Plist Now " .
    • Plist Module :This Is Called the Permanent Bad Sector And Defect Module List .This Contains The Sectors That Are Marked Bad at The Manufacturer Factory .There is No Way You Can Add More Defected And Recently Created Weak Sectors To This Module ,you Need special Hardware And Tools To Manuplate This Module .
    • Smart Module :This Module Contains All the Smart Data That you see In Utilities Like everest ,Once when When I Had started a Massive Debate On E Forums About Temperatures I Was Virtually Killed By The Members and My Fellow Friends ,Well Not To Get Into That Temperature Debate Until I do Not Get To Actually Testing All HDD For Temp Rating .Coming To The Smart Module All The Things Like Bad Sector Count "From Glist " Etc Are Into This Module ,For HDD That Show Smart Errors When You Boot The HDD in The BIOS And Data Cannot Be recovered Can Be Made To Work By Manupalating The Values In This Module .
    • Log Modules :These Modules Are Few In No And They Have Logs Stored By The HDD Disc Operating system Called The Firmware ,When you Do a Selfscan or Use The HDD Manufacturer software For Testing The HDD .

HDD Damage :
Type of Damages :HDD Damages Are Classified Into Two Type Logical And Physical Damages ,Logical Damage Means The Damage is In the File system of the Data "Operating System Stored On the HDD ",Physical Damages Are Damages In the PCB ,The Head And Platter Assembly .Or Defective Or Weak Head Or Bad Area on Platter .Lets discuss About Both Of the Damages In Depth .

• Logical Damages :These Kind Of Damages Are Not Real Damages To The HDD And Are Damages To The File system Of The Operating system On The HDD .This Kind Of Damage Is Rather Common ,Many Software Packages Are There In The Market To do Recovery Of These Type Of Damages .But In My Experience Understanding About File system Organization And File Formats Is Also Very Important .

Crack open that dead iPod

There are zillions of tutorials online to tell you how to open your iPod. I recently found my dead 4G iPod somewhere in my cupboard. I'm not much of a music person, however the iPod was a nifty storage device. I decided to gamble about Rs275 and ordered a replacement battery from dealextreme.com (free shipping). It did take a while to arrive (almost 15-20 days) since it is shipped using general post. The battery ships with two nylon tools to open your iPod. However the tools are kinda flimsy and weak. I tried like a moron for 3 days to open the damn thing but it wouldn't so open at all. I then took it to the local computer repair dude who refused to touch it, saying he only fixes iPhones!! After much trial and error and almost resorting to metallic tools at one point I finally cracked it open.

Here is how should work for most iPods. I'm not responsible for you voiding your warranty though

1. Hold the iPod firmly in your hands with the LCD screen facing upwards.
2. Get a guitar pick (preferably the stiffest you can find)
3. Try as hard as you can to push the guitar pick in the gap between the face and metallic bottom. This is the critical part and which I got wrong a zillion times. You need to push the face plate sideways to create a gap for your pick. Patience, keep trying. When you get worked up and irritated give it up for a bit and take a deep breath.
4. Now slide the pick all around, working it bit by bit to push the faceplate away from the bottom. Be careful not to break the holding clips.
5. After you're done removing the faceplate, you'll notice that there is a wire connecting the LCD to the main board (on the bottom half). Don't touch this wire or remove it.
6. You should notice a HDD on the bottom face with a tiny IDE like connector. You can safely disconnect this but be careful as the wire is really delicate.
7. The battery should be under the HDD, it is stuck to the bottom with epoxy and can be popped out by using the guitar pick again. The wire, however, goes under the main logic board and then connects to it. To remove this wire you will need a Torx T6 screwdriver (which is part of most good screwdriver kits). You need to loosen the two screws that are at the dock end of the iPod. After loosening them you can remove the wire connector from the board and pull out the old battery.

7.1 Put back the HDD connector and try powering on the iPod with the new battery. If it works, all good.

8. Now push back your iPod cover carefully and slowly. Remember relax and take deep breaths. (If you have sweaty palms like me, this will take a while)


Congratulations, you have a fixed iPod. Don't worry if you couldn't follow the instructions to the tee, the replacement iPod battery that you order will usually come with a decent set of instructions. The important bits are avoiding metallic tools (nasty scratches) and the initial cracking open of the case which is detailed in step 3.

Do let me know if it helps or if you have any doubts.

Crack open that dead iPod

There are zillions of tutorials online to tell you how to open your iPod. I recently found my dead 4G iPod somewhere in my cupboard. I'm not much of a music person, however the iPod was a nifty storage device. I decided to gamble about Rs275 and ordered a replacement battery from dealextreme.com (free shipping). It did take a while to arrive (almost 15-20 days) since it is shipped using general post. The battery ships with two nylon tools to open your iPod. However the tools are kinda flimsy and weak. I tried like a moron for 3 days to open the damn thing but it wouldn't so open at all. I then took it to the local computer repair dude who refused to touch it, saying he only fixes iPhones!! After much trial and error and almost resorting to metallic tools at one point I finally cracked it open.

Here is how should work for most iPods. I'm not responsible for you voiding your warranty though

1. Hold the iPod firmly in your hands with the LCD screen facing upwards.
2. Get a guitar pick (preferably the stiffest you can find)
3. Try as hard as you can to push the guitar pick in the gap between the face and metallic bottom. This is the critical part and which I got wrong a zillion times. You need to push the face plate sideways to create a gap for your pick. Patience, keep trying. When you get worked up and irritated give it up for a bit and take a deep breath.
4. Now slide the pick all around, working it bit by bit to push the faceplate away from the bottom. Be careful not to break the holding clips.
5. After you're done removing the faceplate, you'll notice that there is a wire connecting the LCD to the main board (on the bottom half). Don't touch this wire or remove it.
6. You should notice a HDD on the bottom face with a tiny IDE like connector. You can safely disconnect this but be careful as the wire is really delicate.
7. The battery should be under the HDD, it is stuck to the bottom with epoxy and can be popped out by using the guitar pick again. The wire, however, goes under the main logic board and then connects to it. To remove this wire you will need a Torx T6 screwdriver (which is part of most good screwdriver kits). You need to loosen the two screws that are at the dock end of the iPod. After loosening them you can remove the wire connector from the board and pull out the old battery.

7.1 Put back the HDD connector and try powering on the iPod with the new battery. If it works, all good.

8. Now push back your iPod cover carefully and slowly. Remember relax and take deep breaths. (If you have sweaty palms like me, this will take a while)


Congratulations, you have a fixed iPod. Don't worry if you couldn't follow the instructions to the tee, the replacement iPod battery that you order will usually come with a decent set of instructions. The important bits are avoiding metallic tools (nasty scratches) and the initial cracking open of the case which is detailed in step 3.

Do let me know if it helps or if you have any doubts.

Wretched Wednesday.....!!!

Its 10:17 Pm......It's that time of day that most people look forward to.......while they are packing their lunch in the morning,while they are taking bites outta toast with one hand.....as they try to steer their way out of that mayhem with the other..,while the boss is fuming and pointing at his watch as they are walking in 10 minutes late b'cz that darn blouse needed ironing...,while they are frantically trying to make the deadline ..constantly cursing the day they chose this profession!!!Its crazy ...I know!! (I rest my case about the evils of IT)...

To me, this is very important... this period of time,this little slice of my day which ,right before I sail off to Dreamsville,helps me reminisce,clear my mind off all the jarring traffic on my way home..not to mention the chaos and drudgery during the day...

Have you tried this?? It really helps....With a glass of warm milk ...Everything registers better than it did when you first saw or heard it.It may seem like the absolute smallest and insignificant routine,but believe me its priceless.Its what they call, holistic healing!!!Gosh,how stressful and exhausting our lives can get... Its harrowing and difficult to endure.No wonder techies these days quit after a few short years.. And engineers graduating now are just a few projects and a couple of sleepless nights away from total burn out!!!People look for answers in health related articles that are well worded and backed by doctors , who we wouldn't be running to in the first place, if we learn how to give ourselves a break at the right time.

I am all for,working persistently,driving myself insane for better results(when I'm being paid handsomely,Of course),sticking my nose up in the air and then strutting around thinking I'm better than everyone else(Why not,when I'm good at my job)....When we are having a good day.. we better milk it for all it's worth(we get so few of them)!!... But when I think about all the drawbacks associated with it..Such as... No time for family..No sleep...No TV....No sitting around doing nothing(Now this is a talent I have lovingly cultivated..I'm so good at it...If only I could put it on my resume :) :):) ).....No sleep(OK seriously..I need my 8 hrs,without which I'm irritable and grouchy)....,I wonder if its really worth it!!!!

What happened to the cushy..comfortable... easygoing lives people led back when it was not a taboo to not be an engineer???
When,going after our dreams was more important ,even if it meant owning a flower shop!!!!
Where people did not just go with the flow and end up getting caught in this rat race!!!!

After achieving everything we have.. after getting where we are.... after learning and receiving medals and trophies for being outstanding at things we will probably never do again in life.... Have we failed to learn how to do the simplest thing in life???Or did we forget??

The battle of the Coffee beans

I have been a ardent fan of coffee from times immemorial. The whole experience of coffee, cigerrates and philosophy combined with the beautiful girls around is like a high. All was well when my favorite coffee shop was all by itself serving people its laid back coffee, and the smoke and the conversations. There was no jazz, no fancy items in the menu and yes, no pesky hookah’s.

Then one fine day, like it happens to all the laid back places, another coffee shop sprung up right next to our good old coffee shops. This was a supposedly up maket, more jazzy and better coffee shop. Like any other loyal guy, i stuck to my coffee shop, but then curiosity had me. That’s when i decided to visit.. and mind it only visit, for inspection purposes only the new jazzy coffee shops.

So when i walk in, i see a nice ambiance.. not bad they score here.. and than the people serving coffee. Now they are all Chinese. Not that i want to racist or anything, but its funny bcoz communication just comes to a stand still there. You speak English and they answer in what is called the menu language, the entire script which u can find in the menu kept in front of you. Anyways that somehow doesn’t bother much because don’t discuss politics with him. So with difficulty i place my order.. which was a ordeal by itself.. There was no mention of my good old cappuccino nor the espresso. I had to actually struggle to find that between a slew of JAZZY coffees.

Then when i finally order, and then settle down to drink… there are a bunch of people next to me, smoking hookah. I have no problem with the hookah actually, being a smoker myself.. but what pisses me off is the taste and the smell. I mean u have a hookah, u bloody well put tobacco in it.. we are not asking for some dope. Atleast stop putting apple, orange flavoured shit or worse goat milk.. I mean of the government does not give u permission to put tobacco.. sell the good old ciggis.. they are sufficient.. When i try and ignore all that and trying to get into a small conversation with my friends.. the speakers behind me are blurting out “Father Figure” by George MIchael.. and that kills it all. And to top it all.. the list of songs repeat themselves after one round is up.

Now i wonder.. whats jazzy in their, The coffee serving guys who speak the “menu” language, the menu itself which has everything in the front page other than good old plain coffee, the hookahs that spew apple, orange, mint and occasionally goat milk or the music that repeats. Let me go to my good old coffee shop and think about it over a cappuccino.

Chandni Chowk to China postponed to January 2009

Every now and then, we go all out to get you the most exclusive piece of news from the world of
showbiz and this time too it’s no different. One of the most looked forward to films is the Akshay Kumar- Deepika Padukone starrer Chandni Chowk To China. While the makers were toying around with the idea of releasing this film around Christmas this year, the latest is that the film has now been pushed to January next year (2009).

In fact, the makers, Warner Bros., would be coming out with ads on September 9th in all the leading newspapers announcing the new release date of Chandni Chowk To China. September 9th incidentally also happens to be Akshay Kumar’s birthday.

So, the die-hard Akki fans will have to wait till Sept 9th to know when the star’s action comedy flick, Chandni Chowk To China, will release.

Lehman plunges on concerns about capital levels

Lehman Brothers Holdings Inc. shares plunged to their lowest level in more than a decade Tuesday amid investor concerns that the battered investment bank is running out of options to raise capital.

Investors, anxious about the possibility of a bank failure after the near-collapse of Bear Stearns in March, punished the stock in early afternoon trading. The stock plunged $5.61, or 39.6 per cent, to $8.54 — the lowest level Lehman's stock has hit since the financial meltdown of 1998 triggered by the collapse of hedge fund Long-Term Capital Management.

The nation's fourth-largest securities firm has been seeking to boost liquidity after suffering $8.2 billion in write-downs and credit losses since the financial crisis began last year. Lehman had hoped to find a major investor before announcing third-quarter results Sept. 18, when it is widely expected to take another round of steep losses.

Uncertainty about Lehman's financial position has prompted speculation that the investment bank might announce quarterly results early, a move that could also stem the stock's slide. Prashant Bhatia, an analyst with Citigroup, said Lehman could release details about the third quarter as soon as this afternoon.

"At that point, we expect more clarity around where they are in terms of both earnings for the quarter and any strategic initiatives," Bhatia said. "A pre-announcement will likely be a catalyst to stabilize the stock."

Lehman could report a loss of between $2 billion and $4 billion, according to analysts. That would be on top of a $2.8 billion second-quarter loss, which was the first since Lehman spun off from American Express Co. in 1994.

In addition, Lehman Brothers is also working to quell criticism from major credit rating agencies. On Tuesday, Standard & Poor's put Lehman's debt on CreditWatch Negative because of the steep stock decline, which means the agency may lower the company's ratings within months. Such a move would increase the amount of money Lehman pays to issue debt.

"The CreditWatch listing stems from heightened uncertainty about Lehman's ability to raise additional capital, based on the precipitous decline in its share price in recent days," said Standard & Poor's credit analyst Scott Sprinzen.

The steep decline in Lehman's shares began shortly after Dow Jones Newswires reported that the head of South Korea's financial regulator said talks about a possible investment had ended. Lehman Chief Executive Richard Fuld had been in negotiations with state-owned Korea Development Bank for several weeks about a capital infusion.

However, it appears that report itself is being disputed. Yoo Jae-hoon, a spokesman for South Korea's Financial Supervisory Commission, flatly denied any such statement was made. He said the regulator was "not in a position" to "broadcast how the deal is going."

Mark Lane, a spokesman for Lehman Brothers, declined to comment. A spokesman for KDB could not immediately be reached for comment.

Like other investment banks, Lehman has been hit hard by deterioration in the credit and mortgage markets since the middle of 2007. Global banks during the past year have lost more than $300 billion from mortgage-backed securities and other risky investments.

In addition to securing an investment from KDB, speculation has also centered on Lehman selling its asset management division Neuberger Berman, and spinning off a portion of the company — such as its troubled mortgage-assets. Analysts have said Neuberger could fetch $7 billion to $8 billion in a sale.

Ladenburg Thalmann analyst Richard Bove wrote in a research note that the company might be asking too high a price for an investment or asset sales. The stock is down more than 80 per cent so far this year, and traded at $67.72 one year ago.

"Buyers seem to believe that Lehman is overvaluing its assets and refuse to hit the bid," Bove wrote in a research note. "The net result is no action."

Fuld, whose own job is said to be on the line, is trying to avoid the same circumstances that caused the near collapse of Bear Stearns. Bear Stearns' share price plunged in March amid rumors that it did not have enough liquidity to stay in business, and that led to its acquisition by JPMorgan Chase & Co.

However, in this case, Lehman Brothers is said to be having no credit or counterparty risks. Sanford C. Bernstein analyst Brad Hintz said in a note to clients that anxiety about Lehman might be driving the stock lower, but that the government would not let the company simply fail.

"Let's recognize that the Federal Reserve is supporting the funding of four surviving large capitalization brokers, so the sharp decline in Lehman stock today is an equity issue, not a credit or counterparty issue," said Hintz, a former chief financial officer for Lehman before becoming an analyst.

In Washington, Treasury officials refused to answer specific questions about Lehman Brothers but said Treasury Secretary Henry Paulson and other officers were closely following market developments. "We are monitoring markets and are in regular contact with market participants," said Treasury spokeswoman Brookly McLaughlin.