Laptop power supply repair

I have seen, on various newsgroups (Dell for example), of people complaining about the power supply socket on the MOTHERBOARD of the laptop. I imagine it gets a lot of mechanical stress, could be some problems with the solder connections there.

Jerry

I think Jerry's conclusion is likely to be the problem you're experiencing now. Opening laptop cases can be a bit complicated at times, but I think you may find the instructions at the Lenovo website.

Locating a new power connector for the motherboard would probably be a wise move if you intend to repair the problem yourself. I've seen various new laptop motherboard power connectors on eBay, but it's likely that numerous online parts vendors would also be selling them.

Straight power cord connectors typically put more stress on the power connection than right-angled connectors do, but manufacturers insist on using straight connectors in most cases, as they may be a couple of cents cheaper (SWAG).

A right-angle connector, in combination with a temporary anchor point on the instrument's case near the port, would be a much more durable connection.

-- Cheers, WB .............

Just make sure you take ESD precautions or you will likely wind up with a paper weight.

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I find it hard to believe that two power packs would fail, especially when they each measure normally, but have you tried measuring each while a 10-100 ohm load is applied to the DC output? Because something like a bad crimp connection could cause the voltage to be normal with no load but much lower with a load. Here a 10 ohm resistor has to be rated for at least 40 watts, a 100 ohm resistor for at least 4 watts.

If the power connector on the motherboard has a cracked solder joint, you'll probably need a soldering iron rated for at least 40W, preferrably at least 50, and even better would be a temperature controlled 60-70W iron.

I don't like using laptops on my laptop because it blocks the air flow underneath, and moving around the hard disk so much can't be good for it. So we put our laptops on tables that can swing out of the way and have frames permanently attached under the bed frame. I tried building this out of wood, but it was too bouncy, so I had the frame welded from aluminum.

If the plug is pressing on a body part it will keep failing.

YMMV and IME of course, but I've had to repair more laptop power sockets used with right angle connectors than straight ones. Mainly I think because the right angle ones tend to stay in if the cable is snagged, where the straight ones just pull out.

Right angle plugs themselves do seem to survive longer than straight ones though :)

Lee

I keep my laptop on a laptop cooler with two fans. The cooler I keep on a plastic cutting board. I put the cutting board on a pillow on my lap. I think both my lap and the computer stay cool enough.

-- I don't understand why they make gourmet cat foods. I have known many cats in my life and none of them were gourmets. They were all gourmands!

I pulled enough of the electrical tape off of one of the supplies so that I could measure the voltage with it plugged into the laptop. The voltage was still 20.1 volts.

-- I don't understand why they make gourmet cat foods. I have known many cats in my life and none of them were gourmets. They were all gourmands!

Is that while the laptop fails to operate?

Yes.

-- I don't understand why they make gourmet cat foods. I have known many cats in my life and none of them were gourmets. They were all gourmands!

Well if you want to peel the laptop apart, inspect the connector and soldering. I've repaired several HP laptops that failed because the pin in the connector became loose where the back of it was punched into the lead going down to the board. Others were broken at the solder union and others were broken inside the solder. Seems to be an HP thing though. Dells generally have a fairly robust arrangement inside and fail atthe plug end. My Asus also had a plug failure by design. I found a 90 degree plug and spliced it onto a Dell supply and have been using it for a couple years.

I bought a new power jack and it plugs in to the motherboard rather than being soldered. I got a service manual pdf file and it says that the screws used in the Thinkpad are nylon coated and should not be reused. Is it really necessary to use new screws?

The manual does not really say how to replace the power jack. It does say that to replace the 1200 Structure frame, I need to:

For access, remove these FRUs, in order: v ?1010 Battery pack? on page 63 v ?1020 Ultrabay Slim device? on page 64 v ?1030 Hard disk drive cover, hard disk drive, and hard disk drive rubber rails? on page 65 v ?1040 Palm rest or palm rest with fingerprint reader? on page 67 v ?1060 Keyboard? on page 75 v ?1070 Modem daughter card (MDC-1.5)? on page 77 v ?1080 PCI Express Mini Card for 802.11 a/b/g wireless LAN? on page

79 v ?1100 PCI Express Mini Card for wireless WAN? on page 83 v ?1120 Keyboard bezel and wireless WAN antenna cable (AUX)? on page 86 v ?1130 Fan assembly? on page 89 v ?1150 LCD assembly? on page 94 v ?1160 Base cover? on page 98 v ?1190 SIM card slot? on page 1061

Then it says to

Remove the ac power jack cable.

I am hoping that I will not have to remove all those parts. Do you know which ones I will have to remove?

-- I don't understand why they make gourmet cat foods. I have known many cats in my life and none of them were gourmets. They were all gourmands!

You will find out as you take it all apart at your large ESD prepared bench. Be aware of type and length of screws and other odd hardware as you take it apart them. If you put a long screw in a short hole, or miss a shim or washer, it will dimple the outside surface, short something or break the retainer. Pay close attention. A digital camera and quick sketch has been handy. If the screws are Nylon coated, then use a spot of Permatex thread locker blue. If they are nylon screws, they will likely distort or break the heads off if over-torqued.

Power Jack plugs into MOBO? If you say so. How do you replace the jacks that the jack plugs into? Bet it's soldered. The answer would have been a replaceable jack bolted to the frame with a cable to the MOBO rather than directly to the MOBO, but that would have been .0001c too much for large scale production cost. You must realize that cost is a far greater concern than customer satisfaction, or everybody would be taking the garbage back to where they bought it for a refund. People would be sitting at a desk in an air conditioned room with an expensive piece of office equipment rather than taking a cheap toy out to play in the dirt.

If the screws are Nylon coated, then use a spot of Permatex thread locker blue. If they are nylon screws, they will likely distort and break the heads off if over-torqued. If you put a long screw in a short hole, it will dimple the outside surface, short something or break the retainer. Pay close attention.