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geismar mtx 45 manualFor a better experience, please enable JavaScript in your browser before proceeding. It may not display this or other websites correctly. You should upgrade or use an alternative browser. Among them is a huge list of official Apple Service manuals from 2010 on back. Thought I would share as this could be a valuable resource for future projects. On a side-note, I never have figured out why the iMac I was targeting doesn't power up. The trickle voltage from the PSU is working, and diagnostic LED 1 lights up accordingly, but no signs of life other than that. Any ideas on how to proceed with that are much appreciated, though probably should try not to sidetrack the thread too far. (EDIT: If anyone happens to have any ideas, I went ahead and made a separate thread for that over on the iMac forum: ) It's the same site I got the manual from for a G5 I was working on in 2013. I lost track of the site, but now you've posted it. So thanks!!! I'll be glad to throw them on my OwnCloud if I ever get that thing up and running. (Work has been limiting my play-time lately ). Until then though, if anyone wants to volunteer. Grabbed the service manual for my Mid 2009 MacBook. Thanks! The service manual Apple provided is very detailed. Ah, the good old days. Now you have Apple doing everything they can to prevent self repair of their products. Even back then, after a few perfunctory tests in the troubleshooting section the repair solution was all too often replace logic board. Even back then, after a few perfunctory tests in the troubleshooting section the repair solution was all too often replace logic board.I'm referring to the Apple 1 and 2 series of computers. Among them is a huge list of official Apple Service manuals from 2010 on back. Any ideas on how to proceed with that are much appreciated, though probably should try not to sidetrack the thread too far.http://micronetglobal.com/userfiles/canon-d400-camera-manual.xml
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(EDIT: If anyone happens to have any ideas, I went ahead and made a separate thread for that over on the iMac forum: )Yeah, they didn't have that either. It's easier to do that if you can control your customers by denying them the ability to repair your product. I am of the opinion that because of the latter (willingness to surrender control of your thinking) that Apple is still a success because it's not something most people want to admit to. It's like drugs. You keep coming back for more but you try not to show you're doing them. Also I like this image demonstrating what not to do with a MagSafe connector I thought that would prevent shorting. It’s along the same lines as don’t stick your credit card into the optical drive slot. Among them is a huge list of official Apple Service manuals from 2010 on back. Thought I would share as this could be a valuable resource for future projects. Can never hoard too many files if you ask me lol. Thank you for sharing! This sidebar will go away, and you'll see fewer ads.We also boast an active community focused on purchasing decisions and technical aspects of the iPhone, iPod, iPad, and Mac platforms. The site may not work properly if you don't update your browser. If you do not update your browser, we suggest you visit old reddit. Press J to jump to the feed. Press question mark to learn the rest of the keyboard shortcuts Log In Sign Up User account menu 32 Apple Service Manuals As soon as I can figure out how to do it on mobile, I’ll sticky the post. 3 share Report Save level 2 2 years ago Use the Apollo app. Perhaps on the same site.All rights reserved Back to Top. Please do not offer the downloaded file for sell only use it for personal usage. Looking for other manual? For this no need registration. May be help you to repair. You could suffer a fatal electrical shock. Instead, contact your nearest service center. Note! To open downloaded files you need acrobat reader or similar pdf reader program.http://rbsten-tel.com/images/blog_images/canon-d50-owners-manual.xml In addition, Also some files are djvu so you need djvu viewer to open them. These free programs can be found on this page: needed progs If you use opera you have to disable opera turbo function to download file. If you cannot download this file, try it with CHROME or FIREFOX browser. Translate this page: Relevant NOTEBOOK-PC forum topics: Apple Busmouse II M2706 lehet-e ellenorizni DOS 6.22-Win7 PC-n ? Sziasztok A kerdes az, hogy lehet-e, es ha lehet hogyan. Egyszeru adaptert el tudok kesziteni. A neten nem talaltam semmi hasznalhatot. Udvozletem Tisztelt Mesterek. A gepet hasznaltan vette, talan fel eve. Ennyi volt a garancia is,amit vallaltak. Sajnos nem tudtak megcsinalni. Valami alaplapi problemat emlegettek. Minden mast cserelgettek, de nem lett jo. Valaki vallal ilyen gep javitasat emberi aron. Tisztelettel: Oreg Tom Apple iMac grafikus kartyak keresztkompatibilitasa Tisztelt kolegak,Hibas kartyaval vettem, a dobozon nvidia 7300 at ir, de benne 7600 volt, MXM, amit az Apple szervizben epitettek bele, de mindegy, teljesen beadtada az unalmast, nem javithato. A netten utannanezve teljesen irrealis penzt kernek egy hasznalt, de amugy is a pusztulasra itelt katyakert. Most, a hirdetesekben talaltam egy bontott ATI kartyat amelyet ugyanaz az evjaratbol szarmazo iMac 1225-bol mazsolaztak ki, mukodik es elfogadhato aron. A kerdesem az az, hogy kompatibilis e a ket kartya. A netten sokfele velemennyel szolgalnak es arra az okolszabalyra hivatkoznak, hogy ha valami egy apple slot-ba bekattinthato az akkor mukodni is fog, habar en erre nem vennek merget. Ha a tisztelt kolegaknak van e teren tapasztalata vagy raszaladt egy olyan infora amely igazolja vagy cafolja az okolszabalyt azt nagyon megkoszonnem. I also have board View, please request as this is exe file this is board J44 MLB-4GB. The schematic doesn't specifically reference 820-3436, so I would assume it's valid for several boards.http://ninethreefox.com/?q=node/11421 Airport proximity on the board is non existing, so if you have 129 reads on it, just ignore it. Similar manuals: You can write in English language into the forum (not only in Hungarian). And by having access to our ebooks online or by storing it on your computer, you have convenient answers with Apple Service Manuals 2013. To get started finding Apple Service Manuals 2013, you are right to find our website which has a comprehensive collection of manuals listed. Our library is the biggest of these that have literally hundreds of thousands of different products represented. I get my most wanted eBook Many thanks If there is a survey it only takes 5 minutes, try any survey which works for you. Learn more - opens in a new window or tab This amount is subject to change until you make payment. For additional information, see the Global Shipping Program terms and conditions - opens in a new window or tab This amount is subject to change until you make payment. If you reside in an EU member state besides UK, import VAT on this purchase is not recoverable. For additional information, see the Global Shipping Program terms and conditions - opens in a new window or tab Learn More - opens in a new window or tab Learn More - opens in a new window or tab Learn More - opens in a new window or tab Learn More - opens in a new window or tab Learn More - opens in a new window or tab See the seller’s Contact the seller - opens in a new window or tab and request a shipping method to your location. Please enter a valid postal code. Please enter a number less than or equal to 10. All Rights Reserved. User Agreement, Privacy, Cookies, and AdChoice Norton Secured - powered by Verisign.http://www.gasparedicaro.com/images/bt-paragon-550-corded-telephone-answering-machine-manual.pdf Report this Document Download now Save Save Apple MacBook Pro Service Manual For Later 67 (3) 67 found this document useful (3 votes) 6K views 283 pages Apple MacBook Pro Service Manual Uploaded by Jonathan Long Description: Full description Save Save Apple MacBook Pro Service Manual For Later 67 67 found this document useful, Mark this document as useful 33 33 found this document not useful, Mark this document as not useful Embed Share Print Download now Jump to Page You are on page 1 of 283 Search inside document Lincoln Peirce They Both Die at the End Adam Silvera The Perks of Being a Wallflower Stephen Chbosky The Alter Ego Effect: The Power of Secret Identities to Transform Your Life Todd Herman Midnight in Chernobyl: The Story of the World's Greatest Nuclear Disaster Adam Higginbotham Real Friends Shannon Hale Are You My Monster. Howard McWilliam The Devilish Duke Maddison Michaels The Jetsetters: A Novel Amanda Eyre Ward Footer Menu Back To Top About About Scribd Press Our blog Join our team. Browse Books Site Directory Site Language: English Change Language English Change Language Quick navigation Home Books Audiobooks Documents, active Collapse section Rate Useful 67 67 found this document useful, Mark this document as useful Not useful 33 33 found this document not useful, Mark this document as not useful Collapse section Share Share on Facebook, opens a new window Facebook Share on Twitter, opens a new window Twitter Share on LinkedIn, opens a new window LinkedIn Copy Link to clipboard Copy Link Share with Email, opens mail client Email. Now, the Mac Pro returns with a completely redesigned look. Apple revisited the architecture of the Mac Pro's internal components in order to maximize performance and minimize heat. With a unified thermal core, Apple opted for a leaner, lighter, and quieter structure that was more streamlined. The unique cylinder design stands just 9.9 inches tall with a diameter of just 6.https://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/162920228b319a---9130-powerware-ups-manual.pdf6 inches, which allows it to be a professional workstation that can actually sit on your desk. It is also quite common that customers throw outTry Google Search! I am owner Bugera Bass Head and I would like manual for it. Specialy Tips for setting up Bugera. Thanks. J. Charger - Profoto B2 250 Air TTL To-Go Kit 901109 Posted by: Tran Tuan 2021-01-20 06:32:55 I plugged in the charger to charge the battery but it didn't work up. Leaving and not bothering to come back. Huge waste ofo time. You should upgrade or use an alternative browser. Does anyone have, or can point me to the Tech Manuals, service manuals on how to test the PS, or any tips. I don't even know where the LEDs are. I get power into the PS but only 25.8 volts on the 4th pin on the output, if that helps. Anyway, any suggestions would be great. Thanks, SweetDoug Check on eBay. I might warn you that if you do find a genuine Apple service manual for your iMac, it's probably going to be a photocopy and expensive. Apple keeps a close hold on all their service manuals. Only genius bars and AASPs have them. If you are capable of repairing the PS.great. If replacing the PS is the plan if it is bad.save yourself some time.and order a replacement now. - Nick I might take it to an electronics guy I know, who could work on it. But I'll probably just take a flyer and order one from ebay. If you're referring to the availability of service manuals for Macs, think proprietary, think trade secrets, think Apple.;D Have a look at this from ifiixit.com on changing the Power Supply and familiarise yourself with the procedure. Your imac is on the cusp of Apple declaring it obsolete and will not work on it at an Apple Store.I'm one of those open source libertarian types who likes to at least, try things on their own, maybe learn a bit. I've got the thing torn apart right now.BANHTRUNGTHUVIP.COM/upload/files/comtek-m-72-manual.pdf If the PS circuit board back side is facing you--solder connections on the back facing you, on the top right where the plug for the output is, top right, I'm only getting some power at 08, 25.6 volts I think. Is this dead? 15 - 16 13 - 14 11 - 12 09 - 10 07 - 08 05 - 06 03 - 04 01 - 02 SD Any way to be more specific. I've looked for a pict somewhere, but can't find anything.General Background Shot of the iMac What I Think Are The LEDs Another Shot of the LEDs Hope this helps, SD Close but no cigar!! EDIT: iMac (21.5-inch, Mid 2011) Service Manual is here: CAUTION: Watch out for phony add-on etc.Big help in the right direction. Now, if I can find a cheap hard drive caddy for the thing--Somebody thought they'd take the drive out and took the caddy with them!--I could be up and running for under a hun! SD The LEDs are located on the bottomleft edge of the logic board (under a piece of black mylar tape) and can only be seen whenlooking through the lower vents of the enclosure. Refer to the next page for a close up graphicof the troubleshooting LEDs.Location of Diagnostic LEDsThe LEDs are located under the mylar tape, on the bottom, left corner of the logic board. They can only be seen when looking through lower vents of rear housing: DS Tape! What's next!? Juz' duc'tape'er tagether. My buddy who's got a mac shop said the same thing! No pride. I'd already figured it wouldn't work.DS Tape! What's next!? Juz' duc'tape'er tagether. My buddy who's got a mac shop said the same thing! No pride. I'd already figured it wouldn't work. For 2016 and newer models (except 2016 Mazda3) new online manuals are also available, viewable on desktop, tablet and mobile devices. Look it up with EveryMac.com's Ultimate Mac Lookup. For help, please refer to Mac Identification. For complete disclaimer and copyright. Service Manual IMac 27-Inch, Late 2012 and Late 2013 and IMac Retina 5K, 27-Inch.https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16292022d12b80---9131-52a-manual.pdfWhen replacing the stand, use a fine-tip black permanent marker to neatly write the serial number on the bottom of the new stand. Note: If replacing the VESA mount tongue, write the serial number on the underside of the VESA mount tongue. General Troubleshooting Update Software and Firmware Important: Before you begin troubleshooting, ensure the correct version of OS X is installed, and check for and apply the latest software and firmware updates. Computers sometimes exhibit symptoms that indicate the wrong version of OS X system software is installed. Check Apple Support article HT1159: Mac OS X versions (builds) for computers to make sure system build is correct for this computer model. Firmware is the name given to software that is written into memory circuits such as flash memory, that will hold the software code indefinitely, even when power is removed from the hardware. Firmware on Intel Mac computers is designed to be updated if necessary by running the OS X Software Update check (available in the Apple (i?? ) menu) while the computer is connected to the Internet. If the computer detects out-of-specification or no Random-Access Memory (RAM), the screen will remain black but the computer will beep. This error condition may be due to physically damaged RAM, installing an incorrect type of RAM, or not having RAM installed. Some RAM may appear to pass POST, but still cannot be used by the operating system. In this case, the computer will display a gray screen, sound three beeps and repeat beeps until computer is turned off. The solution to both of these situations is to first re-seat RAM and test computer again. If RAM fails POST again, remove all installed RAM and test by installing one by one each RAM module that has been verified to work correctly on another computer (i.e., “known-good” RAM) or order new RAM. For more information, refer to Apple Support article: HT5860: Mac computers: About startup tones.https://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/16292023f44651---9130-eaton-manual.pdf Quick Check Procedures Resetting the System Management Controller (SMC) The System Management Controller (SMC) is a chip on the logic board that controls all power functions. If the computer is experiencing any power issue, such as not starting up, not displaying video, sleep issues, or fan noise issues, resetting SMC may resolve it. For more information and instructions to reset the SMC on different computer models, refer to Apple Support article HT3964: Intel-based Macs: Resetting the System Management Controller (SMC). Note for iMacs: If you press the power button while inserting the power cord, the iMac will enter a mode in which the fans run at full speed. For more information, refer to Apple Support article TS1433: iMac: Fans run at full speed after computer turns on. Resetting Parameter RAM (PRAM) PRAM stores certain system and device settings in a location that OS X can access quickly. Exactly which settings are stored in the computer’s PRAM varies depending on the type of computer as well as the types of devices and drives connected. To reset PRAM: 1. Shut down the computer. 2. Locate the following keys on the keyboard: Command, Option (Alt), P, and R. You will need to hold these keys down simultaneously in Step 4. 3. Press power button. 4. Immediately press and hold Command-Option-P-R keys. Important: You must press this key combination before the gray screen appears. 5. Hold down keys until computer restarts, and you hear startup chime a second time. 6. Release keys. For more information, refer to Apple Support article PH14222: OS X Mavericks: Reset your computer’s PRAM. Starting Up in Safe Mode Safe Mode is the state into which you can start up your Mac by performing a Safe Boot. Starting up into Safe Mode does several things that can help troubleshoot and resolve software or directory issues that may exist on the startup volume. To start up in Safe Mode: 1. Make sure computer is shut down. 2. Press power button. 3.BANGTUTRANG.COM/upload/files/comtek-m-216-manual.pdf Immediately after you hear startup sound, press and hold Shift key. Note: The Shift key should be held as soon as possible after startup sound but not before. 4. Release Shift key when you see the screen with a gray Apple and progress indicator (looks like a spinning gear). Note that booting into Safe Mode will take longer than a normal startup. In OS X v10.6 and later, a gray progress bar is also displayed on the bottom of the window during Safe Boot. For more information, refer to the following Apple Support articles: HT1564: OS X: What is Safe Boot, Safe Mode. TS1884: Safe Boot takes longer than normal startup Recovering a Lost Firmware Password Only Apple Retail Stores or Apple Authorized Service Providers can unlock the following Mac models when protected by a firmware password: MacBook Air (Late 2010 and later) MacBook Pro (Early 2011 and later) iMac (Mid 2011 and later) Mac mini (Mid 2011 and later) Mac Pro (Late 2013) Refer to Apple Support article TS3554: Recovering a lost firmware password on Mac computers manufactured after October 2010. For more information on Apple Diagnostics, refer to HT5781: Using Apple Diagnostics. Apple Service Toolkit 2 (AST 2) AST 2 is a cloud-based diagnostic system to help technicians triage and verify repairs for Mac computers released in Mid 2014 and later, except for MacBook Pro (Retina 5K, Mid 2014). With AST 2, technicians will be able to initiate diagnostics wirelessly on a user's device using a Diagnostic Console (a web application on a Mac or iPad). Technicians will also be able to view diagnostic results on the Diagnostic Console. For more information, refer to the following Apple Support articles: OP476: Latest Apple Service Toolkit download links and documentation TP1105: AST 2 Reference Guide - Table of Contents TP1118: AST 2 Reference Guide - Table of Contents (Retail) Apple Service Toolkit (AST) AST is a suite of diagnostic tools that checks Intel-based Mac hardware components and provides detailed diagnostic logs for review. AST runs on a local server, managing multiple Ethernet clients via NetBoot. For more information, refer to the following Apple Support article: TP586: AST Reference Guide - Table of Contents Mac Resource Inspector (MRI) MRI, which is part of AST, is a quick triage tool that checks for the presence of hardware and reports sensor readings. Sensors are located on a variety of parts, including cables, fans, storage devices, the power supply, the display panel, and the logic board. Use MRI to help isolate failures and avoid unnecessary part replacements. MRI complements ASD, which is a more in-depth repair verification tool. Note: If all AST checks pass and a component is still suspected to be at fault, verify with other diagnostic tools.IC0G CPU AXG current On logic board Check cable connections to logic board; test with known-good logic board. IC0I CPU VCCIO high-side current On logic board Check cable connections to logic board; test with known-good logic board. IC0M CPU MEM 1.5V current On logic board Check SO-DIMMs; test with known good SO-DIMMs; test with known-good logic board. IM0R DIMM 1.5 S3 current On logic board Check SO-DIMMs; test with known good SO-DIMMs; test with known-good logic board. IN1R PCH 1.05V current On logic board Check cable connections to logic board; test with known-good logic board. Tb0p BLC Proximity Board temp On logic board Check cable connections to logic board; test with known-good logic board. TC0p CPU Proximity Board temp On logic board Check cable connections to logic board; test with known-good logic board. TCXr CPU Max Die temp (PECI) On logic board Check cable connections to logic board; test with known-good logic board. TG0d GPU Die cooked temp On logic board Check cable connections to logic board; test with known-good logic board. TG0p GPU Proximity temp On logic board Check cable connections to logic board; test with known-good logic board. TH0O HDD 00Bv1 Temp Built into the HDD Check HDD cable connections to logic board; test with knowngood HDD. TL0p LCD Flying Lead temp Mounted to back of LCD display Check LCD cable connections to logic board; test with knowngood LCD display; test with known-good logic board. TL1p TCON Local Board temp Built into LCD display Check LCD cable connections to logic board; test with knowngood LCD display; test with known-good logic board. Tm0p MLB PSU Local Board temp On logic board Check cable connections to logic board; test with known-good logic board. Tm1p MLB GPU Local Board temp On logic board Check cable connections to logic board; test with known-good logic board. TM0p SO-DIMM 1 Proximity Board temp On logic board Check SO-DIMMs; test with known good SO-DIMMs; test with known-good logic board. TM1p SO-DIMM 2 Proximity Board temp On logic board Check SO-DIMMs; test with known good SO-DIMMs; test with known-good logic board. TM2p SO-DIMM 3 Proximity Board temp On logic board Check SO-DIMMs; test with known good SO-DIMMs; test with known-good logic board. TM3p SO-DIMM 4 Proximity Board temp On logic board Check SO-DIMMs; test with known good SO-DIMMs; test with known-good logic board. TPCD PCH Die temp On logic board Check cable connections to logic board; test with known-good logic board. VC0C CPU Core voltage On logic board Check cable connections to logic board; test with known-good logic board. VC0G CPU AXG voltage On logic board Check cable connections to logic board; test with known-good logic board. VC0M CPU MEM 1.5V voltage On logic board Check SO-DIMMs; test with known good SO-DIMMs; test with known-good logic board. VD2R On logic board Check power supply cable connections to logic board; test with known-good logic board; test with known-good power supply. ID2R VG0C GPU Core Voltage On logic board Check cable connections to logic board; test with known-good logic board. VH05 3.5 HDD 5V voltage On logic board Check HDD cable connections to logic board; test with knowngood HDD. VM0R DIMM 1.5 S3 voltage On logic board Check SO-DIMMs; test with known good SO-DIMMs; test with known-good logic board. VN1R PCH 1.05V voltage On logic board Check cable connections to logic board; test with known-good logic board. VR3R VR 3.3V voltage On logic board Check cable connections to logic board; test with known-good logic board. CPU Core Current On logic board Check cable connections to logic board; test with known-good logic board. IG0F GPU Frame buffer GPU Frame buffer 1.5V high-side 1.5V Current Suggested Action IH1R SSD 3.3V Flash Storage Card On logic 3.3V Current board IM0R Memory I-Sense DIMM 1.5V Current On logic board Check SO-DIMMs; test with known-good SO-DIMMs; test with known-good logic board. VC0C CPU 0 Core CPU Core Voltage On logic board Check cable connections to logic board; test with known-good logic board. VC0M CPU 1.35 S0 CPU Memory Voltage On logic board Check cable connections to logic board; test with known-good logic board. VG0C GPU 0 Core GPU Core Voltage On logic board Check cable connections to logic board; test with known-good logic board. VG0F GPU FB GPU Frame Buffer Voltage On logic board Check cable connections to logic board; test with known-good logic board.Avoid touching the logic board or power supply while the computer is plugged in. Be very careful not to touch tools to logic board components other than the test pads. After unplugging the computer from the electrical outlet, wait two minutes before removing the display panel, disconnecting modules, or substituting cables and components. This will allow the power supply and logic board time to discharge. Refer to the following Apple Support articles for more information: TP833: iMac and Displays: Power Supply Cover Instructions TP820: iMac (27-inch, Late 2012 and Late 2013) and iMac (Retina 5K, 27-inch, Late 2014): Safety iMac (27-inch, Late 2012 and Late 2013) and iMac (Retina 5K, 27-inch, Late 2014) models have four diagnostic LEDs and two pairs of test pads that can help you troubleshoot the computer without removing the logic board. The coin battery located on the back of the logic board provides power to the real-time clock (RTC) and parameter RAM (PRAM) when the computer is not connected to an AC power source. The RTC maintains the date and time, while the PRAM stores information such as speaker volume, screen resolution, startup disk selection, and recent kernel panics. The coin battery is designed to last several years and does not normally require replacement. However, if there are issues with the functions listed above, the RTC and PRAM may need to be reset or the coin battery may need to be replaced. A. Diagnostic LEDs See the full description of LED behaviors below the locator image. B. Coin Battery Voltage Test Pads Shut down and unplug the iMac. Allow approximately two (2) minutes for the power supply to discharge. Measure the coin battery voltage by using a voltmeter set for DC. Place the probes on the pads (negative probe on left pad, positive probe on right pad) in location B, shown below. If the voltage is 2.7 volts DC or less, the coin battery should be replaced. C. Real-Time Clock (RTC) Reset Pads Important: Do not make contact with any of the surrounding components or traces while performing this procedure. Some of the smaller components can be knocked off very easily. Physically damaged boards warrant a logic board replacement. Shut down and unplug the iMac. Reset the RTC by shorting the pads in location C, shown below. Use the tip of a flat-blade screwdriver to touch both pads at the same time.This LED will turn on when you connect the iMac to a working AC power source. The LED will remain on as long as the computer is on or asleep. Disconnecting the power cord and plugging it back in will turn this LED back on, even if the computer is still off. After disconnecting and reconnecting the AC power source, this LED could remain off: If the AC power source is missing or disconnected. If the logic board is disconnected from the power supply or the AC receptacle. If the power supply board is faulty. LED 2 Indicates that the computer is turned on. This LED will be on as long as the computer is turned on (but is not asleep) and the power supply and voltage regulators are working correctly. LED 3 Indicates that the computer and video card are communicating. This LED will be on when the computer is communicating properly with the video card. If LEDs 1 and 2 are on and you heard the startup sound but LED 3 is off, the backup battery (on back of logic board) may need to be reseated or the video card might be installed incorrectly or need replacement. LED 4 Indicates that the computer and LCD panel are communicating. This LED will be ON when the computer is turned on and a video signal is being generated. If LED 4 is on and there is no image on the display, the LCD panel or the cables between the LCD and logic board might be installed incorrectly or need replacement. If no LED is visible: Disconnect the power cord from the computer and wait 15 seconds to reset the power supply and LED status. Reconnect the power cord and check the LED status again. Verify the AC source. Verify that a known-good power cord is connected. Verify the cable connection between the AC inlet and the power supply. Verify the cable connection between the power supply and the logic board. Verify the power supply. If the second LED is not visible when the power button is pressed: Verify that the power button is connected to the power supply. Verify power button functionality.