Apple Mac Schematic Diagrams

Discussion in 'Mac - General discussion' started by Stammah, Apr 15, 2010.

  1. Stammah

    Stammah Regular member

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    Hello. Does anyone knows where I can download for free or purchase the schematic layout diagrams of the Apple Macs? Im planning on repairing them down to component level.

    Cheers!
     
  2. Paula_X

    Paula_X Guest

    not a hope.. only apple repair centers have access to that information.
     
  3. Stammah

    Stammah Regular member

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    Thanks. I figured.
     
  4. Paula_X

    Paula_X Guest

    if you open one up they are pretty much stock chipsets etc.. nothing that special.. except they always alter the eeprom revision numbers and occasionally use odd variants on standard things like north bridge or network hardware..

    in reality they aren't worth the money people pay for them new.. second hand market is pretty much non-existent due to designed in obsolescence.
    I have repaired mobos for people in the past.. as favours to save them buying complete new setups for basically sound machines but old..

    IF I had tried to make an actual living from it the price would be higher in time and parts than the systems were worth.. 5 hours troubleshooting, testing and repairing an 8 year old mobo?.. realistic charge has to be £15 an hour (just to break even running your own business),. plus tax.. 17 1/2% .. plus parts.. when a comparable (newer) system complete with everything.. maybe £100

    unless you have a company employing you to do them in bulk.. on a production line basis.. they aren't worth fixing.. and the "bounce" percentage on computer mainboards after manual repair is over 35% .. after scrapping the 25% that are beyond economic repair on first inspection.. a failed component is usually part of a chain of events.. one blown cap might seem like a simple fix.. until it goes bang again 2 days later.. and again.. and again.. taking out maybe the cpu the second time. (remember the dell e-machines?)

    Overall (and I know an apple repair center worker) a faulty mainboard, unless it's a "known and documented" stock fault isn't worth the cost of attempting a repair.. once failed and "repaired" they have to be classed as "patch up for necessity" systems to be replaced as soon as funds allow.. Apple centers replace rather than dig out the soldering iron.. the boards go back to the forensics part of the manufacturers operation for investigation and/or refund if found to have failed within the internal QC structure.

    30 years electronics taught me one thing.. once something fails once it is 80% more likely to fail again in a very short time frame than another exact same system (tv video whatever) that has never been touched. Often replacing one faulty component will stretch the remaining older parts (they all age together after all) and then all kinds of odd faults start cropping up.. Good example is a leaky smoothing cap.. leaks enough to drop a power rail by perhaps .8v .. not enough to cause any outward signs of distress.. one day it shorts hard overloading everything powering that rail.. which may survive but be weakened.. so you dive in and replace the obviously blown cap.. power up.. greeted by smoke as the regulators and supply droppers all self destruct.. throwing ac down a dc rail and doing untold damage.

    I go back to the days of valves in tv sets.. doubt many here remember the exploding cap in the cathode circuit of the pcf805 frame output stage... big bang.. bad smell.. white line across screen.. obvious which cap had blown, so most engineers replaced it (after cleaning out all the foil and gunk.. a VERY big bang).. same set would arrive again.. same fault maybe 4 months later.. nobody ever thought to check the huge 2 watt 200 ohm resistor sitting parallel to it.. which had a habit of going high value up to about 400k (obviously.. as the height dropped people just wound up the height control to compensate).. putting way to much volts on the 50v cap (big rating for a cathode bypass cap maybe? later sets from the same manufacturer only had a 25v cap in this position, and we saw them all the time for "reduced height" before the explosion)).. with no effective ground path through the resistor instead of a healthy 12-18v bias the cathode would rise to ht rail voltage.. frame stage 250v .. bang as the cap explodes.. eventually.
    The REAL fault causing this was shorted turns in the frame output transformer leading to high anode current.. or occasionally tracking in the scan coils plug/socket (right up against the sound output valve).. something like 8 inches away from the apparent cause of the problem.

    I don't consider component repair of pc's to be a viable business choice.. ok for something you want for yourself, (I knock back and turn away dropped laptops and water damaged stuff all the time.. it's cracked or wet or doesn't even flicker any sign of life?.. I don't even open it up.. not worth getting involved.. same with missing or wrong position screws.. if somebody else has been in there before me, and is unskilled to the point they can't even put all the screws back in the right places if at all.. I don't want to spend 6 hours sorting out some n00bs "repair" attempts) but a nightmare of returns and constant "under warranty" free work for you if attempted on a direct to public service or as the basis for a sales trade. I'm not questioning your electronics know how.. but I am advising you make a real world financial risk assessment of the situation before getting involved in something which even large electronics repair businesses don't touch. Is it worth spending £1500 on a reflow station you might use once in 4 months? how about the jigs to test the 20 or so different boards you are likely to encounter (the common ones.. to test all the current boards takes about 1900).. and as for crapple?.. no info = no chance .. I limit my checks on those to the plug in bits and obvious faults like bad caps... tho I usually just turn them away because they are apple.
     
  5. Stammah

    Stammah Regular member

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    Thanks for your tutorial. But really. I never spend 5-6 hours trying to figure out what is wrong. I generally spend the max 2hrs finding the problem. Its worth my time because I charge 1/2 the price for a new motherbaord and my customers are ok with it.

    I personally never looked on a old macbook or macpro. Hail no! No profit there lol. Im aimed at the late 2008 - current apple products. Where BGA's are concerned, MOST times I can replace it with just a heat gun. I have many experience doing it the "ole-school" way.

    PS: I like your website!
     

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