Dell D600 motherboard dead, Ac adapter dies when plugged in.

By computer-solutions ·
I have a Dell D600 and a few other motherboards that when I plug the ac adapter in the ac adapter dies then you have to unplug it to get it to reset. What Im looking for is what part on the motherboard is bad when this happens?? Also if anyone has a place to get the electrical plans for dell motherboards to help figure out the problem would be useful and appreciated. I see many boards like this and if I could fix it instead of having to spend 200.00 on a new one it would be great.
Thank You

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OK the problem here is that you have a DEAD SHORT CIRCUIT

by HAL 9000 Moderator In reply to Dell D600 motherboard dea ...

However finding the problem can be the hard part and depends on the test equipment that you have available.

If you are just plugging in a bare M'Board with no CPU or RAM and get this I would look at the initial Power Input Socket and any passive components behind that so look for Bridge Rectifiers or a series of Diodes that are arranged as a Bridge Rectifier being dead, burnt out or just destroyed. After that you can look at Capacitors that go between the different Sides of the Voltage Rails as a Direct Positive to Negative connection to filter out any surges as these may be a straight Open Circuit or worse still a straight Short Circuit.

If you can not find the problem at this level then you are unlikely to find the problem at all as you need to lift at least one side off the M'Board to test as an straight In Circuit Test will not be sufficient as other circuity will come into play and give you incorrect readings. If you have a dead IC Integrated Circuit you are virtually stuffed as these are all Surface Mount and Ultra Sonically Welded in Place with the legs way too close together to allow even the finest Soldering Iron to be able to remove one let alone replace the same unit. The same applies to Surface Mount Resistors and the other double ended bits that you see soldered to the M'Board these are Heat Sensitive and just applying a soldering Iron to one end can be enough to destroy the component. Attempting to unsolder both ends and remove the glue holding the thing in place will defiantly destroy the item and attempting to replace the same item will have the same effect.

Basically if you have the right equipment it's safe to remove anything that goes through the M'Board but not anything mounted to one side only of the M'Board.

Depending on the individual M'Board you can replace some Diodes, Bridge Rectifiers, Capacitors of all types, Transistors and nothing else. Even replacing those items without a very fine earthed soldering iron and a high content Silver Solder can be questionable as some items require too much heat to solder in properly and you destroy the component while soldering them in place. Small Electrolyte Capacitors and the TO220 Case Transistors are both good examples of this on Computer M'Boards and then if you don't use a Earthed Tip Soldering Iron you can feed a power spike into the M'Boards tracks destroying more components so you are making a bad situation worse.

However if you have lots of money you can buy a Weller Soldering Station to remove the smaller Surface Mount components and refit them. This unit has a belt feed which you load different components in on their paper strips and it will load them onto the M'Board and then either Ultra Sonically or Ultra Violety solder the components in place. Not sure what one of these costs as it's been a long time since I looked but 15 years ago they cost about 65K + and then you had to add the cost of components and disposables meaning solder and glue. The one that I looked at had a 4 inch work area that is a 4 inch circle that you could work within and you could replace the VLSI Integrated Circuits up to about 300 connections to the circuit board without any problems but as you are working blind you need to know what you are doing.

As far as the Components are concerned all the Passive components like Diodes, Bridge Rectifiers, Capacitors, Green Caps are freely available from the bigger Electrical Suppliers but any of the IC's particularly the VLSI IC's may be special order with a minimum requirement to buy so for any North or South Bridge IC's you would probably have to buy several thousand of each IC to make it economic for the suppliers to get them in stock. The more rare a component is the more that you have to buy to make it worthwhile to attempt to do repairs.

As an example when the Z80 Processor or Integrated Circuit first became available I had to buy 3,000 at a time and they cost me about $75.00 each but about 5 years latter I could buy in lots of 1 for under $1.00 each.

The more that the IC makers make of a particular item the cheaper it is and the more freely available it is, but honestly repairing these M'Boards isn't economic unless you have some really expensive M'Boards to work on and here I mean something that costs in excess of $40,000.00 on a exchange basis. $200.00 M'Boards are not worth the time or effort as you can burn up much more in Labor attempting to find the fault which can not be repaired so you have wasted your time and lost money into the bargain. You also need a good range to diagnostic tools as a Multi Meter isn't good enough for most work so you'll need a very good CRO, Signal Generator/Sine Wave Generator and a Vatric which is a stable Power Supply that is adjustable from above mains voltage down to a few volts in either AC or DC depending on what you need at the time. To setup a half way decent Workshop to do this work will cost you well over a $1,000,000.00 without the best equipment possible and then only the bare minimum that you actually need and once you have isolated the problem component you'll need some means of replacing it if it's even possible. I used to do this with IBM Main Frame Boards but they where worth the Time & Effort but run of the mill PC M'Boards are way too cheap to even consider doing this with. Also if you don't understand any of the above jargon you shouldn't be even attempting this repair work.


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yes and if TheChas were here he would say look

by sgt_shultz In reply to Dell D600 motherboard dea ...

at the power supply electrolytic capacitors and see if you can find any that appear damaged (like bulged out on top). when they fail they will short power to ground as HAL suggests. they might have something about this on the motherboard website. post back if you find out would you?

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Dell D600 motherboard dead, AC adapter dies when plugged in

by techkmeadows In reply to Dell D600 motherboard dea ...

First check your battery to see if it is part of the Dell Battery Recall. (THIS IS ALL DONE ON DELL'S SITE} If it is try to run the laptop without the battery installed. I have seen this problem before. At Dell's site follow the steps to have the battery replaced as part of the Dell Battery Recall. This will take approx. 20 business days. If the laptop does not work without the battery then the faulty battery has damaged the motherboard. You will have to replace the maotherboard. DO NOT USE YOUR LAPTOP WITH THE BAD BATTERY.

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