LukeLindblom
Level 1 (32 points)
Desktops

Q: iMac DV SE Will Not Power On At All

I got an iMac G3 at an auction tonight for $5. It is an iMac DV special edition, model M5521.

 

I got it home and plugged it in and it does NOTHING. No light. No click. Nothing at all.

 

I tried the reset button in the RAM cover, and I also tried removing the PRAM battery. The PRAM battery appears to be dead, but the iMac should still boot, bcs from what I understand, this isn't an "old world" mac.

 

Also, I don't HAVE to have a keyboard attached for the Mac to POST, right?

 

I have found some others with the same problem online, but everything I find is so old, so I figured I'd just ask again.

 

Any help would be appreciated!

MacBook Pro with Retina display, OS X El Capitan (10.11.2), 16GB RAM, 15", 512GB SSD.

Posted on Feb 25, 2016 7:12 PM

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LukeLindblom

Q: iMac DV SE Will Not Power On At All

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  • Helpful answers

  • by Kenichi Watanabe,Helpful

    Kenichi Watanabe Kenichi Watanabe Feb 26, 2016 5:39 AM in response to LukeLindblom
    Level 8 (38,490 points)
    Mac OS X
    Feb 26, 2016 5:39 AM in response to LukeLindblom

    Any iMac model uses the New World ROM design, if that matters for this situation.

     

    The iMac could simply be "broken," like the power supply is bad.  But it needs to have a good PRAM battery to operate properly.  They are inexpensive, so if you want to make it work, you should replace it to rule out PRAM battery as the problem.  It looks like this

     

    http://eshop.macsales.com/item/NewerTech/BAA36VPRAM/

  • by LukeLindblom,Helpful

    LukeLindblom LukeLindblom Feb 26, 2016 5:39 AM in response to Kenichi Watanabe
    Level 1 (32 points)
    Desktops
    Feb 26, 2016 5:39 AM in response to Kenichi Watanabe

    I replaced the CMOS battery with a new good one. (I have a tester for those things) It still does nothing at all. I've tried multiple cords and outlets, just to rule that out.

     

    Power supply? Any other (inexpensive) ideas?

  • by Allan Jones,

    Allan Jones Allan Jones Feb 26, 2016 9:55 AM in response to LukeLindblom
    Level 8 (35,086 points)
    iPad
    Feb 26, 2016 9:55 AM in response to LukeLindblom

    The commonly failed part in that model is the "PAV" board (for "power-analog-video"). The ill-conceived passive cooling system (fanless) used in that model tends to cook the board resulting in failures, especially if the computer were used in areas consistently over about 80°F

     

    If the reset button and a new PRAM batt didn't get things going enough to POST, then I'm starting to suspect the PAV board. The problem in replacing that board is that new ones are no longer available, leaving you with "used/pulled" boards that have already been subjected to some degree of roasting while in service.

  • by Jan Hedlund,

    Jan Hedlund Jan Hedlund Feb 26, 2016 10:24 AM in response to LukeLindblom
    Level 6 (9,869 points)
    Feb 26, 2016 10:24 AM in response to LukeLindblom

    At least the earlier iMac models had a power board fuse (I do not know whether or not the same applies to your computer), which could be checked/replaced by a qualified service provider. The board in question was not intended for user access. All work in this section can be very dangerous because of high-voltage circuits, and must only be carried out by someone with the necessary expertise. Charges can remain in various components even after the computer has been switched off and disconnected from the mains. Generally speaking, a broken fuse is merely a symptom. One must always investigate why there has been an excessive load.

  • by Jeff,

    Jeff Jeff Feb 26, 2016 10:37 AM in response to Allan Jones
    Level 6 (11,559 points)
    Feb 26, 2016 10:37 AM in response to Allan Jones

    Unlike a typical power supply in a computer, removal/replacement of the P-A-V board is an involved procedure, because of its location and the numerous connections to it from other components.  As Jan has stated, the high voltage remains stored for many months, so the CRT must be discharged prior to attempting any repair in and around it.  Not following industry-standard safety precautions when working around any CRT-type display or TV can result in serious or fatal electrical shock.

  • by Kenichi Watanabe,

    Kenichi Watanabe Kenichi Watanabe Feb 26, 2016 10:35 AM in response to LukeLindblom
    Level 8 (38,490 points)
    Mac OS X
    Feb 26, 2016 10:35 AM in response to LukeLindblom

    After replacing the PRAM battery, did you press the PMU button?  This web page has some pictures and procedure

     

    http://mrjcd.com/junk/PMU.jpg

  • by LukeLindblom,

    LukeLindblom LukeLindblom Feb 26, 2016 12:01 PM in response to Jeff
    Level 1 (32 points)
    Desktops
    Feb 26, 2016 12:01 PM in response to Jeff

    That's why I'm not messing with what's under the top cover. I know you don't take apart CRT's. I have replaced the PRAM battery, and I've pressed the PMU reset many times. Where can you get a PAV board now though?

     

    And I KNOW there are no authorized service providers for these anymore.