Laptop battery pack cell replacement. - Page 1
Forum section: electronics / beginners

author: Barto1361
author_rank: Newbie
timestamp: February 07, 2012, 07:50:51 pm
content: Hi everyone!I'm relatively new on the forum, but I've been subscriber of Dave’s blog for about a year and reading this forum for few months now and I’m happy to finally join EEV forum officially!So, the thing is my dad’s laptop battery died after steadily declining in capacity for about a year. Laptop is Lenovo SL510 and battery pack model is 42T4751. After taking off the cover I found 6 Li-On cells packed neatly and after tracing wires and connections, It seems that they are connected parallel in two's which as far as I know is standard type of connection in laptop batteries. I found out that cell was made by Sanyo and the model number is R1112 (specs). I can't seem to find exact model in Europe, so since I'm not that good with electronics I'll need help finding an alternative that would fit the specs and not make a little fire. Any help will be appreciated.

author: Neilm
author_rank: Super Contributor
timestamp: February 07, 2012, 08:30:14 pm
content: These batteries are for OEM use only and are therefore not usually sold to non recognized battery manufacturers. This is due to the inherent dangers of working with Li-ion batteries.The pack when designed would have been tested to many different standards, there are a couple from UL, the IEC standard (62136) and UN38.3 for moving the batteries. These involve some serious abuse to ensure that they are safe.Neil

author: sonicj
author_rank: Frequent Contributor
timestamp: February 07, 2012, 08:51:52 pm
content: search eBay for "18650 tabs"look for cells with similar (or better) specs than the stock sanyo cell. Stay clear of the "trustfires" and "ultrafires". stick with sanyo, sony, panasonic, etc.Capacity: >2150mAhCharge Current >1.505AMax Discharge Current >4.3AThis Sony would work:LinkCapacity: 2600mAhMax. Charge Current : 2.6AMax. Disharge Current : 5.2A-sj

author: SgtRock
author_rank: Unknown
timestamp: February 07, 2012, 10:46:01 pm
content: Dear Sonicj:--Excellent sleuthing there, my good man. I was just speculating on whether I would be able to do this for a laptop battery. I will use this information the next chance I get, and I will remember to stick to the approved brands. Thanx.“Before turning to those moral and mental aspects of the matter which present the greatest difficulties, let the inquirer begin by mastering more elementary problems.."Sherlock Holmes 1887 -Best RegardsClear Ether

author: PeterG
author_rank: Frequent Contributor
timestamp: February 08, 2012, 01:01:56 am
content: Before you spend $$$ on new cells, i would look very closely at the pcb inside the battery. It is common for Li-Ion packs to have a suicide chip that stops the battery from charging after about 1000 charges. This is to prevent them becoming unstable with old age.I know IBM and Apple use such a setup.Regards

author: SgtRock
author_rank: Unknown
timestamp: February 08, 2012, 01:22:32 am
content: Dear PeterG:--A friend of mine had a huge Heathkit Stereo Amplifier (250 Watts Per Channel RMS, which I built for him), that he would run into clipping all the time, I mean, listening to Heavy Metal, who could tell, from distortion. Feh. He had an ear for clipping like the Ice Cream Man. I inspected and found that the Speaker Protection Relays had fried, so I wired around them, and told him to hold it down until the replacement parts arrived. Needless to say he next toasted the resistors and I do not know what all. I was not to pleased, so he sent the it back to Heathkit and for the price of a new kit they fixed it for him.--My question is can one circumvent the control chip on these laptop PCBs, or is is unacceptably dangerous?"Does not squirrel crack nuts on bough of oak tree."Lao Fu 1410 1620Best RegardsClear Ether

author: PeterG
author_rank: Frequent Contributor
timestamp: February 08, 2012, 01:27:14 am
content: It is generally deemed "unacceptably dangerous". I spoke to a company that repacks batteries and they now refuse to repack Li-Ion packs for Laptops.From what i have heard, it is simply easier and safer to buy a new pack for your laptop.Regards

author: vtl
author_rank: Regular Contributor
timestamp: February 08, 2012, 02:08:35 am
content: Quote from: PeterG on February 08, 2012, 01:27:14 amAlso cheaper with the economies of scale of laptops. I love DIY but I don't understand why someone would bother butchering their laptop pack when you can simply buy a new one cheaper.

author: Psi
author_rank: Super Contributor
timestamp: February 08, 2012, 02:20:46 am
content: Be careful about the after market battery packs though. The cell they use can be pretty budget quality.I got an extended lithium battery for my laptop and it works really well capacity wise, i get around 6.5 hours just sitting there with the lcd on half brightness.However the battery has an awful self discharge rate. Two months in the laptop bag and its down to 50% charge.A good quality lithium battery is like 3% self discharge per month.

author: SgtRock
author_rank: Unknown
timestamp: February 08, 2012, 02:54:44 am
content: Dear Vtl:--People who have an interest in doing this, may not be quite as stupid or crazy as you imply. Leaving aside for the moment safety considerations (which I have not yet adequately researched), and with the understanding that I am merely speculating, and not advocating, allow me, please to get down, to cases.1) A person is given an IBM Lenovo SL510 and a couple of battery packs that will not hold a charge. Might he not want to try, making one good battery pack out of two duds, for no money.2)A person has a dud IBM Lenovo SL510 battery pack with one bad cell. Would he not perhaps be tempted to pay $12.00 (including shipping) for a single new Sanyo cell as opposed to paying $50 (shipping included) for a new genuine replacement battery pack.--I might add that I do not at the moment see anything inherently more dangerous in the procedure, provided you solder them up correctly, than what is being done with electric race car battery packs, and power tool battery packs, every day. But I am willing to be persuaded otherwise.--I often have to fix things for people who have little or no money, for little or no money, so I always have my eye out for a fiddle that will make a repair affordable."Three weeks in the lab will save you a day in the library every time"R. Stanley Williams 1951 -Best RegardsClear Ether

author: PeterG
author_rank: Frequent Contributor
timestamp: February 08, 2012, 03:16:42 am
content: I think the same applies for any multi-cell li-Ion battery.You can see there is a limit to the number of recharges by carefully reading the manual for these devices. They once used to read "the Battery can be recharged over 1000 times." now days the li-ion based devices read "can be recharged 1000 times." You will note there is a difference in the wording of the battery life.There is no way i would replace only 1 cell in an aging pack.Regards

author: sonicj
author_rank: Frequent Contributor
timestamp: February 08, 2012, 04:00:35 am
content: i was soldering a high discharge 3 cell lipo last week when my helping hands slid somewhere they shouldn't have. luckily, the pack was discharged & the clips did not weld the circuit permanently closed! normally, i tape everything down to avoid this sort of incident, but i had already pulled up the tape thinking i was done, but decided to rework the last joint and got lazy/complacent. damn near crapped my pants!-sj

author: damo
author_rank: Contributor
timestamp: February 08, 2012, 04:40:32 am
content: I believe that when they manufacture the packs, they need to match the batteries (especially the parallel ones) for internal resistance (and another spec from memory, may be capacity). This is to prevent things like over charging a single cell in the pack and large discharges between cells due to variants in internal resistance. If you were to replace the individual batteries in the pack, you would need to do this as well (see below). I would not use cells from different used battery packs because the age of the batteries means their internal resistances will be different (and capacity), again see below.From above: Risk of fire with Li packsNot saying don't do it, just beware

author: amyk
author_rank: Super Contributor
timestamp: February 08, 2012, 09:50:28 am
content: Depending on the battery management chip you may need to reset the charge counter on it and program in the capacities of the new batteries. The older ones are usually a bit more friendly but some new ones even require the firmware to be reloaded to discourage reuse. Datasheets and information are difficult to find for obvious reasons, but there are sites out there, you'll just need to search.

author: Kozmyk
author_rank: Regular Contributor
timestamp: February 08, 2012, 10:39:21 am
content: The cost of replacement packs for older laptops can be prohibitively expensive i.e. more than the laptop is now worth.I replaced the 18650s in my old Fujitsu-Siemens Amilo Pro pack.I paid around £5.50/cell, I didn't go for the cheapest, around £3/cell. 8 cells £44They wanted around £150 for a replacement pack.The hardest part was opening the plastic case, lot's of fiddly work with a razor saw.Unfortunately, the charging circuit was either shot or deliberately nobbled as mentioned above.I test charged the cells prior to assembly, using quite a fancy lipo charger - Hyperion, so I know it wasn't the cells at fault.I've given up on the old V7010 as a portable device so now it's a mains powered bench PC running my Hantek DDS-3x25 signal generator using Mechatrommer's wonderful GOLTEK software.Comparable Lenovo replacements are more common and much cheaper.My main laptop is now a Lenovo T61Running Linux. Yay!

author: metalphreak
author_rank: Frequent Contributor
timestamp: February 08, 2012, 03:43:09 pm
content: They don't actually "solder" the tabs on either. They use some kind of arc/spot welding technique.

author: kripton2035
author_rank: Super Contributor
timestamp: February 08, 2012, 04:28:15 pm
content: something like this :http://www.pittnerovi.com/jiri/hobby/electronics/welder/index.htmlor this :http://ultrakeet.com.au/index.php?id=article&name=cdWelder_p2

author: bfritz
author_rank: Regular Contributor
timestamp: February 08, 2012, 08:24:35 pm
content: This is something I know a bit about, as I worked for a major PC manufacturer, designing battery packs, fuel gauging, and safety and charging circuitry.During manufacture of the cells, they are matched. Matching procedure varies depending on the cell manufacturer, but basically matches the impedance and voltage of the cells. This is done so that when cells are welded in parallel, they will share current equally. Replacing only one or two cells in a pack, or replacing with used cells with slightly different characteristics, leads to unequal current sharing or voltage mismatch, which can result in what is referred to in the industry as "Rapid Disassembly". :-)The Lenovo pack does contain a pack disabling device. If the cells got too far from being voltage matched, or the circuit detected current flowing when the protection FET's were off, or overtemp conditions beyond certain limits, the device triggers. Just shorting around the Permanent Failure (PF) device will not fix the pack. The fuel gauge in the pack (Lenovo has one in all their notebook packs, as do Dell, HP, etc.) monitors this device and once it has blown it, or the secondary protection circuit has blown it, it sets a PF flag in a location of non-volatile memory. Until that flag is cleared, the pack will refuse to enable the protection FET's, and will attempt to blow the fuse again, as it thinks it was unsuccessful in fully blowing the fuse, and will try again. Lenovo also password protects the calibration and fuse bits in the fuel gauge and safety circuitry, so you would need to hack that before being able to reset the PF bit in non-volatile memory.If you find the pack gives you some runtime, and will charge, then the cells are simply nearing end of life. I would suggest buying a new pack from the manufacturer of your laptop. Many of the aftermarket packs are not well made, and not worth what they charge, as you will be replacing them very soon. The plastics are often ultrsonically welded shut, or glued. Disassembly without destroying the plastics is quite difficult. Even if that is accomplished, then you must weld new cells in place, or get cells with welded tabs attached and solder those in place. There is typically very little extra room inside the plastics. It is very easy if you don't know exactly what you are doing to allow a tab or high current strap to lay in contact with the shrink wrap over a cell, that then abrades with vibration, which then causes a fire! A good short across multiple cells can deliver over a hundred amps... plenty to start a fire. I do not recommend repair.If you find the pack will not charge, and gives no runtime, then it is highly likely the PF fuse has been blown. To repair the pack would require reprogramming the fuel gauge / safety part within the pack, and then replacing the PF fuse. The fuses are quite difficult to come by. I know of no distributor who carries them, and buying direct requires buys of the PF fuses in full reels. After doing that you would still need to remedy the cause of the PF, which would may include replacing the safety FET's, and replacing the cells in the pack.Repairing these packs is simply not practical. It can be done if you are tenacious enough, but this must be tempered with the knowledge that you know what you are doing. I know this stuff inside and out, and I wouldn't do it, as repair simply takes too much time.

author: saturation
author_rank: Super Contributor
timestamp: February 09, 2012, 12:44:42 pm
content: Great input, bfritz. Something every laptop/netbook owner should know. Currently the cost of replacement packs is far less than for me to DIY, so I've not even attempted to make DIY packs.

author: amyk
author_rank: Super Contributor
timestamp: February 10, 2012, 10:18:35 am
content: Quote from: bfritz on February 08, 2012, 08:24:35 pmIf you look in the right places on the internet, there is plenty of information about thatNot necessarily in English though (see my point below).QuoteIt depends on where you live. In some places (developing countries mainly) labor is cheap, and a couple of 18650s (and maybe a new chip) will cost far less than an official replacement.

author: bfritz
author_rank: Regular Contributor
timestamp: February 12, 2012, 05:34:23 am
content: Quote from: amyk on February 10, 2012, 10:18:35 amI'd like to see that. Where is such a location. A link to a google translateable link and I should be able to discearn the info. I ask, as the password scheme used would make a brute force method very difficult, and if anything has likely been social engineered. I have the ability to figure out quickly if their password works, or not. I have yet to see any of the manufacturers packs cracked, that were bothering to use a password.QuoteThe real question, is what happens if your house burns down, and the insurance company finds out you "fixed" the pack, and it was the source of the fire? That would make such a "cheap fix" the most expensive fix of your lifetime! Just not worth it...

author: SgtRock
author_rank: Unknown
timestamp: February 12, 2012, 07:55:02 am
content: Greetings EEVBees:"The real question, is what happens if your house burns down, and the insurance company finds out you "fixed" the pack"--Yes after a house fire kills your entire family, it could get even worse in a hurry. What if the Insurance Co. marks you down for piddly diddlies, and you encounter a devastating financial loss? What happens if the Insurance Co. finds out you bought a cheap One Hung Low battery pack, instead of an official Major PC manufacturer battery pack? Indeed what happens if the Insurance Company finds out you "fixed" your television which was connected to line power.--If I were you, I would think twice about removing that mattress tag."I could see that, if not actually disgruntled, he was far from being gruntled."P. G. Wodehouse 1881 1975Best RegardsClear Ether

author: amyk
author_rank: Super Contributor
timestamp: February 12, 2012, 11:30:23 am
content: Quote from: bfritz on February 12, 2012, 05:34:23 amDue to the nature of the information, it tends to be spread out thinly and not easily found, but if you're determined enough it is posisble... I don't remember any specific sites, although here is one I just found:http://batterygroup.vn/bgvn/forum.phpQuoteThe real question, is what happens if your house burns down, and the insurance company finds out you "fixed" the pack, and it was the source of the fire? That would make such a "cheap fix" the most expensive fix of your lifetime! Just not worth it...Talking about risks, it would be interesting to compare the relative risks to other sources, like dying from a serious disease (especially in a developing country), or a car accident. I know that some guys over at candlepowerforums.com use completely unprotected(!) 18650s in flashlights and only a very small percentage of them have actually had any incident. We do hear about batteries exploding and catching fire, but compared to the number actually in use, I would say the percentage is miniscule - otherwise there would be a lot more news about it.

author: SgtRock
author_rank: Unknown
timestamp: February 12, 2012, 05:31:48 pm
content: Dear Amryk:--I checked out the site you provided, and indeed it seems to be a site concerned with Laptop Batteries, Laptop Battery Control Chips, and reprogramming of Control Chips. A couple of the chips mentioned, are even available from Digi-Key.--The response to your statement about such sites was:"Where is such a location.[?] A link to a google translateable  link and I should be able to discearn  the info.".--The rapid typing and the seemingly prosecutorial phraseology, gave me the feeling, that just possibly your credibility was being called into question. It was almost as if the questioner, instead of searching for the information himself, was indicating that the existence of this information was so unlikely that, there was no point in searching for it, and that your veracity would remain in question until, the unlikely event that, such a site was provided. If indeed such was the case, I think the link you provided has gone a long way towards establishing your bond fides.--Now when someone indicates that in their opinion a certain practice is, impractical, imprudent, and unsafe, I am generally willing to accept the assertion and perhaps even agree with it. But, when they go on and on, and begin to get increasingly hostile, I get the feeling that once they have spoken, all discussion is supposed to cease. Feh.--Even though I will probably never repack and reprogram a Laptop Battery, it is indeed good to know how to do it, where to get the information, and what to look out for, if one should need to.--I know for a fact that people routinely repack and re-solder Lithium Ion batteries for power hand tools and RC cars every day, and yet I see few reports in "Catastrophic Battery Fire Weekly" magazine concerning this practice."Extraordinary claims require extraordinary evidence"Carl Sagan 1934-1996Chock-dee-naClear Ether

author: bfritz
author_rank: Regular Contributor
timestamp: February 13, 2012, 01:12:35 am
content: Quote from: SgtRock on February 12, 2012, 05:31:48 pmWow. Are you that unhappy that you just Troll threads here, looking to try and start fights, where there are none?I have yet to see how you have added anything to this thread. The rest of us are getting along just fine, and working to learn something from one another. I have not found places where information about the passwords for major pack manufacturers are available. I do not find the passwords for the packs, at that very site either, but I am taking the time to look, as it is something I am interested in determining: Are the existing safety measures broken, or are people just reverse engineering and creating packs with the existing parts in the marketplace.As far as the comments about there not being any reports of fires or explosions of packs...How many reports of house fires do you see daily? I guess there is no need for smoke alarms then. LOLI know of at least two major recalls of battery packs by major computer manufacturers here in the US. HP had a major recall, where the people I know in the industry believed the issue was a wire abrading and shorting out over time. Even at their cost for the packs, this had to be in the millions of dollars. I know Dell had a recall, where it was believed that small metal fragments from a cell winding machine were wound into the cell, and were causing punctures in the seperator. Again, millions of dollars in cost to fix those concerns. Perhaps you are too young to remember the several incidents with metallic lithium cells. There was one fairly famous one where the battery pack in a mobile radio exploded and burned the face of someone in ASIA. In the world today, if you are a corporation with deep pockets, having safety failures in the 0.01% area could put you out of business very quickly, but that certainly fits your small percentage that we don't need to worry about. For a small business, they are often forced to just shut the doors. I have seen this happen to several smaller battery pack manufacturers in ASIA.An 18650 cell is capable of delivering currents of 100A into a good short. It is quite easy to cause a short with these cells, and start a fire. In my career I have performed abuse testing on hundreds of cells, and given feedback to manufacturers that has helped to reduce risks. If you choose to ignore the risks and operate packs with no safety features in place, or choose not to abide by pack manufacturers best practices, I can only hope you don't experience first hand the failures that not only can, but do occur.Go ahead and believe the risks are not real, or that you are immune. Just remember that you were warned.

author: amyk
author_rank: Super Contributor
timestamp: February 13, 2012, 10:19:06 am
content: Quote from: bfritz on February 13, 2012, 01:12:35 amIt's probably the latter. Some of these people "recell" packs as a business, and if their products have a reputation for going up in flames, it isn't long before they'll have no more business.QuoteI remember those recalls, and that was due to manufacturing flaws in the cells. They had to recall them, because they were certain to short sooner or later.QuoteIf anything, the ones rebuilding packs are going to know the most about shorts (and given how many they work with, have probably experienced more than a few) and how to avoid them. I'm not saying to ignore the risks, but to assess them in relation to other things -- especially since just about everything you do these days seems to have a chance of killing you. Most people won't refuse to fly just because of that 1 in ~10 million chance of dying.

author: SgtRock
author_rank: Unknown
timestamp: February 13, 2012, 03:31:15 pm
content: Greetings EEVBees:--Indeed Amryk was correct, the information on how to defeat the smart battery pack is indeed out there in cyberspace and not just in Thai. Please see the below link to an article by Mathew J. Schwartz from Information Week of July, 2011 titled "Apple Laptop Batteries Hacked By Researcher" -- "Attackers could use a password weakness to render your laptop's battery useless--or overcharge it to start a fire, researcher warns."http://www.informationweek.com/news/security/vulnerabilities/231002536--This article is about Laptop Battery Hacking work by Doctor Charles Miller, who formerly worked at the National Security Agency. I am also an alumnus of the Puzzle Palace, but of a much more humble station than the prestigious Dr. Miller. Now, indeed I am not sure just how likely any of these scenarios are but, but over the years, malicious hackers have done a lot of damage by using manufacturers default passwords. A case in point would be what happened in the UK when the Government Telephone Service Authority decided all cell phone voice mail would have a default password of 1234. Bob's your uncle, and we know whose knickers he is eying.--Also please see below the PDF file, by Dr. Miller, explaining how reprogram to your battery (includes pictures). This is the information that was promised in the Information Week article.http://media.blackhat.com/bh-us-11/Miller/BH_US_11_Miller_Battery_Firmware_Public_WP.pdf--Also I just found Dr. Miller's YouTube Tutorial on Smart Battery Hacking. and as soon as I hit the post button I am going to finish watching it.--They even sell software to do this sort of thing, like "Battery EEPROM Works" - See below link where you can download a demo, and if you like you can buy for $10.http://be2works.com/download.html--It claims to support darn near every smart battery chip ever made including the Maxim's mentioned on the Thai site, that Amryk provided.--Please keep in mind, that I am not advocating that anyone do this, but I do believe that more information is better than less."I have had my results for a long time: but I do not yet now how I am to arrive at them."Carl Friedrich Gauss 1777 1855

author: bfritz
author_rank: Regular Contributor
timestamp: February 13, 2012, 05:46:39 pm
content: Thanks for those presentations SgtRock.I was aware that Apple was using the default keys. In my opinion, the engineers there are a little full of themselves. I actually talked with them a couple times, and they thought there was no need for security, as nobody will ever figure this stuff out. LOLSo yes, Apple is what I would call the "Low Hanging Fruit". The truth is, that even given full knowledge of how the firmware works, you would be unable to cause a safety problem. But that doesn't mean a hacker couldn't cause some damage!The issue is that there is a secondary protection IC, (TI, Maxim, Mitsumi, and Seiko make them) that if the pack ever gets close to an overvoltage condition, it will blow the Permanent Failure (PF) fuse. I think the part that Apple doesn't get, is that a hacker could easily go in, and change the charging voltage requested by the pack in the Smart Battery Gauge (Since they foolishly used the default sealing password), and change the overvoltage thresholds for the primary protection provided by the Smart Battery Gauge.The charger is not a true Level 2 or 3 SMBus charger, so it actually pays no attention to the charge voltage requested, and is hardwired to put out the correct value. But by changing the primary protection thresholds, and disabling any cell balancing, a hacker could cause a cell voltage imbalance, which results in an overvoltage on a cell, that then triggers the secondary protection. The secondary protection would then blow the PF Fuse, which disables the pack. This will likely take many charges to occur, but since there is no real security as Apple uses the default password given by TI, it is quite possible to write a virus that could cause batteries to eventually blow their PF fuses.I have seen the other manufacturers be more rigorous in their approach. The HP, Dell, Lenovo, and other major laptop packs I have seen, do bother to implement a real password. I have yet to see examples of those passwords get hacked.I have seen an example of a RIM battery pack for a mobile phone that was very hackable, even though it was using a password. It used a very simple CRC, actually two seperate 16 bit CRC style passwords. The issue is that the security chip they chose, actually offers a way to attack them one at a time, which along with the hardware knowledge of how the CRC works, made the password very crackable. I know RIM was looking at getting away from that security scheme, but don't know if they did or not.I found the "Battery E2Prom Works" software to be interesting, but of no real threat. They are just repackaging what you can get in an EV-Kit from TI or Maxim. (I didn't even see where they said it worked with the Maxim parts.) It did say that if the battery gauge IC came back reported as "sealed" you needed to assume the part was "Dead" and replace the part. So, this makes it possible to rework a pack, but you would need to replace the IC. I know that Dell also implements some other items in the pack, that if the values are not programmed correctly for that model, the Dell will refuse to charge that battery pack. I didn't see any special mention for Dell, so I assume that software doesn't know the requirements for the different models, and will not work with those Dell packs. (This is a fairly recent change, about the last year, so wouldn't be surprised to have software like that not yet dealt with such packs.)So, I am interested in anyone who does have an example of a laptop pack that actually implemented a non-default password, that has been cracked. I would be interested in seeing such information, in case anyone here does know of those.But, the links to some of the stuff that people have shown, is a good example of why the manufacturers are worried... at least those who don't have Apple's, "We Are Gods", attitude. LOL

author: amyk
author_rank: Super Contributor
timestamp: February 14, 2012, 12:06:47 pm
content: Quote from: bfritz on February 13, 2012, 05:46:39 pmSince SMbus access is restricted to administrator, it would either have to rely on a privilege escalation exploit or clever social engineering. And once someone has that privilege, it's relatively easy to cause hardware damage via other means than the battery: forcing the fans off and pushing CPU and RAM voltages beyond safe limits, for example. Or more obnoxiously, erasing the BIOS. However, malware writers don't choose to do that, as it is far more beneficial for them to steal user information secretly instead of destroy hardware.QuoteThe basic principle of that software is to clone the entire state of the IC, so unless it's not possible to read and clone the Dell-specific stuff (but... how else would the laptop check otherwise if it couldn't read it), I think it's a generic solution. I do know that Dell has been known for somerather sneaky tricks with their AC adapters.QuoteIt seems in many cases it's cheaper to just replace the IC, but maybe for some cases there is an incentive to dig in and reverse-engineer -- and that's one thing you'll find a lot over in Asia. Chip decaps / live EEPROM reading (even from "secured" chips) is relatively common practice. There really isn't much theycan'tdo.QuoteThat's also partly why those who know this stuff don't tend to easily disclose the information to the public. It's a similar situation with things like inkjet cartridge chips (there are of coursesome notable exceptions.)