Dell complaints

m_mckenna · conscientious beginner Joined: 02 Apr 2007 Posts: 2

I have an Inspiron 1150 with the seemingly common A/C power adaptor type cannot be determined..." error. I've had the laptop apart several times and got a temporary fix by resoldering the pins on the AC/DC jack but unfortunately the problem returned. I installed a new jack and while doing so noticed that the bushing on the adapter identification signal line (center conductor) is totally loose in it's hole, therefore not connected to its intended trace in the motherboard. I understand that this is the pin used by the BIOS to determine the a/c adaptor type. I would like to know where this pin goes to next on the board so I can barnacle the pin to this location. Any ideas on where to get this information or how I might resolve this problem without replacing the entire motherboard?

Thanks.

diashto · Posted: Wed Apr 04, 2007 7:06 am Post subject:

In the worst cases when i've been sent out to replace a mobo on an 1150, the entire power jack has comeoff in my hand, so i can only assume that its somewhere around those traces that you've already re-soldered. most likely underneith.

m_mckenna · conscientious beginner Joined: 02 Apr 2007 Posts: 2

I've managed to fix my problem. Hopefully this info will help other folks. I took some pictures of the board and the repair, but can't figure out how to upload it. The pin layout of the DC jack looks like this:

---1--2--1----
---------------
4-----3------4
---------------
4-----3------4

As far as I can tell, there should be ~19.5 volts between 1 and 3, ~12.5 volts between 2 and 3. Pins #4 are used to anchor the part to the board. From what I've read, pins # 1 are the main power, pin # 2 is used to indicate to the bios what kind of charger is connected. My problem of "AC adaptor type cannot be determined..." was due to pin # 2 being disconnected. Using my son's 2 dollar microscope, I guessed where the trace from this pin went. Using the $5000 dollar electronic microsope at work, I was easily able to see where the trace went. The picture shows it quite clearly, but just above pin #2 you should see a PL24 printed on the board. The trace from pin # 2 goes between the L and the 2 to a tiny resistor. My fix was to barnacle pin # 2 to the "a" side of the resistor according to this ascii representation:

-a-resistor-b-
----------------
---1--2--1-----
---------------
4-----3------4
---------------
4-----3------4

The trace is WAY too small, no wonder it breaks for so many people.

If you flip the board over, you should verify that there is zero resistance between pins#1 and the larger resistor beside PL-25.

If someone could tell me how to upload the pictures, the solution would be much more obvious.[/img]

Rocke_T_Sinetist · Posted: Mon Apr 09, 2007 11:36 am Post subject:

Very good work! It could have been an internal trace, not findable with anything. Yes the power plug is a constant problem with current Dell portables. They were standard 'barrel' connectors when I was working on them (2000-01) and seldom had issues.

The 'img' tag is for links. That is, the image has to reside on a web address and the address goes in the img tag. (The BB itself doesn't contain images other than its own graphics.) For poor folks like me on dialup, it's considerate to JPG-compress. More than 100K of filespace does not result in greater displayable detail.
_________________
Rocke T Sinetist
as in, 'it doesn't take a...'

irishcavan · conscientious beginner Joined: 18 Jul 2007 Posts: 1

McKenna, thank you for the images you sent me.. they were a great help to understanding what I might have missed. I have one more question, if you please.

When I plug in the AC adapter (without the battery) I have a faint green light on the 1st and 3rd LEDs, however when I put the battery in, those lights disappear completely. Since the battery is completely depleted at the moment, I have no way of getting even a small charge to it. Could there be something else that I am missing that I need to focus on repairing?

Thanks,
Irish

mavrick_001 · conscientious beginner Joined: 21 Oct 2007 Posts: 1

I've taken an 1150 apart, found the diagram on this page as to the pin outs, I have the 19v ok but between the centre pin (2) and 3 it is only showing 2.85v with the power supply connected, so is this meaning that the dc jack is faulty and the centre pin is not connecting in the barrel properly??? Can't get my head around it. To start off with it would power the fans up for a second then go off, power led flashes, if you press power button power led flashes, pressing again turns off and pressing again starts the sequence over again. There was a stage where it would power the fans and the caps lock light would flash and shut off after 10secs ( had this problem on another inspiron when I used the faulty inspiron's ram) and changing the ram sorted it. But now the faulty inspiron has gone back to starting for 1 second and the above power flashing issues and only the 2.85v on the 2-3 pins.... help please.

I've built a few systems for myself, electrican by trade, moved into alarms and now in cctv so ok with a mulitmeter and soldering but by no means have I any idea on this and bow down to your infinate wisdom and apprecaite any help you can give me, thankyou in advance, Tony UK

jdeadman · Posted: Fri Mar 14, 2008 10:38 pm Post subject: Any new answers

Hello. I am having the same problem and I also am getting 2.9V between #2 and #3 as stated above. has anyone foud that fix? I checked the resistance between #2 and A in the resistor and it's fine so the other problem i do not have.

Thanks in advanced

Rocke_T_Sinetist · Posted: Sat Mar 15, 2008 11:12 am Post subject:

If you get the exact same results as mavrick_001, the problem is more liklely a motherboard regulator. Those are also notoriously flaky.
_________________
Rocke T Sinetist
as in, 'it doesn't take a...'

jdeadman · Posted: Sat Mar 15, 2008 11:38 am Post subject:

Where is the regulator and how can I test it / replace it?

Thanks

Rocke_T_Sinetist · Posted: Sat Mar 15, 2008 12:31 pm Post subject:

The regulator is a set of at least 100 components, all permanent parts of the motherboard.

If you have the 'broken connection' problem, you get a message saying 'adapter not identified' but it WILL come on, at least long enough to say that. (The adapter ID thing is to prevent you from buying a GOOD adapter in the aftermarket, and force you to buy another crap one from Dell.)

If it won't come on at all, blinks power or numlock then goes off or just keeps blinking, the regulator is overloading every time it tries to start, and shuts down. Regulators used to be designed to operate around 75% capacity, so they could lose some and still operate. Now cheapened, they operate closer to 90%, so any loss of capacity kills them. And they cheapened the bejeezus out of the capacitors too, from where their expected lifetime was ~10 years, to where it's ~3.
_________________
Rocke T Sinetist
as in, 'it doesn't take a...'

jdeadman · Posted: Sun Mar 16, 2008 1:15 pm Post subject:

Ok. The basic Problem is that it will not boot with the power supply attached. even if I start the computer on battery and then plug it in, the computer freezes totally and will not do anything. It appears to charge the battery just fine while off. When the power supply is plugged in the only light that comes on is the battery light which flashes green but extremely slow flashing. like off for 15 sec then on for 1

I am attempting to fix this laptop for a friend. when I got it all he said was the hard drive was no longer working. when i looked at it all I did was pull the hard drive out and try it in my external IDE adapter in my main computer but it still didn;t even turn on. THe new hard drive works in the laptop on battery power only.

I guess he can live with it the way it is but I'd like to get it working for him.

Thanks

Rocke_T_Sinetist · Posted: Sun Mar 16, 2008 2:14 pm Post subject:

Gnarly problem. You mean literally 'freezes' when you plug in the adapter, as in stays on but completely stops responding? If it had a straightforward regulator problem, it should be shutting off. BUT....

The regulators in laptops are very busy little networks of switches, able to shut off parts of the chipset but not others. Also, able to switch between battery and adapter, which produce different voltages. All it takes for what you're seeing to happen, is the failure of one switch.

I'd still say it is a motherboard regulator problem. You could eliminate the adapter itself (and its cable and plug) by substituting a known-good one, or using the one you have on a known-working Dell laptop.

If you had the "adapter identification" issue, it probably wouldn't charge the battery. Also, those are another set of regulators and switches. That it charges doesn't mean it will work, or vice versa.

Like I said, gnarly.
_________________
Rocke T Sinetist
as in, 'it doesn't take a...'

jdeadman · Posted: Sun Mar 16, 2008 7:07 pm Post subject:

brutal. Thanks for the info. I will be taking the adapter into wor where I have lots of Dell laptops to try it on. to try and eliminate it. the ac adapter is alot cheaper to replace then the motherboard

Trixi's Mom · Posted: Thu Apr 10, 2008 10:40 pm Post subject: #2 pin connection

We have just replaced the 1150 dc jack and had difficulty with #2 pin accepting solder. Has anyone else had this problem with the solder? We also only get 2-3 volts between the #2 and #3 pin. Does anyone know what the spec is supposed to be? We are also getting the AC Adapter cannot be determined error. The power flashes on as the adapter is inserted, but all lights go off when the barrel is inserted completely. Just about out of battery life, would downloading BIOS update help? Prior to DC jack failure, the unit did charge with currently unrecognized adapter. Thanks for taking time to help.

Rocke_T_Sinetist · Posted: Fri Apr 11, 2008 3:12 pm Post subject:

BIOS is unlikely to change it. Reason, Dell wrote the BIOS to require their own adapter in the first place, they are very unlikely to change that.

If you can find the resistor where Pin 2 is supposed to end up, you could run a wire directly there. But I have no idea where that is or how to tell you to look for it.

Some details are in the thread above, though probably not enough to locate it with that alone.

This probably isn't what you wanted to hear: I'm a fixer, not a tosser. I still use a stereo preamp I built in 1969, and drive a 22yo car. But I think if I were faced with one of these Dells, I would toss it before I spent any more money on it.
_________________
Rocke T Sinetist
as in, 'it doesn't take a...'