Help troubleshooting Dell laptop

[flaVius]

Re: Help troubleshooting Dell laptop

I have a similar issue with my Mobo. It ran off battery power but wouldnt power on from AC. I replaced the jack because it looked suspect. It still wouldnt power on, I found a thread where some1 with a similar problem said theirs would boot if the external monitor port was plugged in. I was sceptical but decided to try it and amazingly the board powered on. As intereting as it was, I still dont know what is the culprit. I am guessing some kind of bad ground. Perhaps you should try and see if your board powers on doing the same.

[arneson]

Re: Help troubleshooting Dell laptop

I also have a dead dell.
The 1150 with no sign of life.
Tried this tip and she came to life with external monitor, still won't power up but this is a start.
I've seen some of these motherboards offered stripped and dead, and now I'm thinking it could be the video section has toasted something.

I'll post if I find an answer, for now I've got another board coming.

[arneson]

Re: Help troubleshooting Dell laptop

I have a similar issue with my Mobo. It ran off battery power but wouldnt power on from AC.Perhaps you should try and see if your board powers on doing the same.

Well thank you I can get the dell to run by plugging in a monitor.
This seems to allow the battery to charge and it will then run by itself.
I am also still trying to figure out what has caused this and you are correct that it is a common issue. This is the 1150 dell.

[flaVius]

Re: Help troubleshooting Dell laptop

I tested my adapter to make sure it was functioning properly, it showed 19.6V out. After contemplating I realized that the jack was not provding a ground to the mobo. I ran a wire from the external casing of the adapter tip (since outside is - inside +) when plugged in to the jack to the top of the monitor port. This enabled the board to post. So i am assuming the external monitor port is provding another point to ground the mobo. As tempting as it is to just solder some wire from the jack to the monitor port I am going to resist and see if I can figure out why the jack isnt providing a ground.

[arneson]

Re: Help troubleshooting Dell laptop

This has become an issue for me.
I have two of these 1150's that power only from a good battery until it's drained.
I can not flash the latest bios because it refuses without ac power.
Many, many others are also searching for this answer, I can't figure it out.
I know that it is not the DC jack, the problem applies to at least one other model, the 5100 I think, the charger supply is not recognized.
Dell's are dying and I'm stumped.

[kc8adu]

Re: Help troubleshooting Dell laptop

those jacks commonly fail.
i replace them with the old style dell 3 pin jack and plug.
that plug has 3 leads in it.
b+,ground, and sense.

[arneson]

Re: Help troubleshooting Dell laptop

those jacks commonly fail.
b+,ground, and sense.

Yup Yup and yup, so it's this sense thing or lack of it that's causing problems.
That would be the smallest center pin heading over to what looks like a darlington arangement and that zener as shown in picture from original post.
Have to figure it's the laptop doing the sensing not the other way.
There are a Lot of unpopulated spaces on these boards and that power scheme sucks.
I'd like to pypass all that just to get her fired up, even if I only use it to charge batteries for the second dead one.

[linuxguru]

Re: Help troubleshooting Dell laptop

The small centre sense pin on the new (cylindrical) jack easily bends or breaks - the old-style jack was far better, but could not reliably handle 19V, 4A that the P4 required. They should have gone with additional pins on the old-style 3-pin jack instead.

I still have a Latitude CPi and an Inspiron 3800 with the old style jacks that are going strong - the former is about 8 years old now and uses an MMC2 CPU module.

[flaVius]

Re: Help troubleshooting Dell laptop

Are you guys referring to the jacks that the PA6-9 adapters plug into? I didnt know those fit in the newer style dells. If they work thats way more cost effective, they are like 25% the price of the newer ones. What are the 2 additional pins for on the new style jacks?

[linuxguru]

Re: Help troubleshooting Dell laptop

Yup - the 3-pin PA6/9 adapter jack/socket. However, note that the single V+ contact on the PA6/9 cannot reliably handle 4A and above - which is what most of the P4 notebooks require when running from the adapter.

[arneson]

Re: Help troubleshooting Dell laptop

The problem with the fragile plug is only one issue on these.
There's also the plastic cover tab making contact with thebottom of the board, damaging a power control chip.
Then there's my problem, motherboard that won't see the charger and will not power.
I could add the latest attempt at fixing this to the Stupid Stuff thread. I have just totally toasted one of the two main boards.
Desperately trying to charge one battery I started jumping power and ground all over the place. Made a pop sound and got a bit warm.
The answer to this could revive many of the dells offered on ebay as "won't charge" laptops, that's why I haven't given up.

[arneson]

Re: Help troubleshooting Dell laptop

Here are some more pics as you asked:

I'm still hashing with these dells.
Bassmen, Your board picture shows a chip to the right side.
It's the Intersil 6247cr power control chip. I think these are blown, and this is why a board replacement is the only answer.

http://www.intersil.com/Applications...device=ISL6247
This is a data sheet, difficult replacement.

[arneson]

Re: Help troubleshooting Dell laptop

Here's a bit more on this, sorry I'm obsessing.
Data is proprietary for the intel version but not for the amd chip, here's the data..

This is how the board utilises ceramic caps.
This probably fails due to overheat, just my HO.

All the 1150's I've opened up have a large dust ball hidden in crevice of heatsink,
people say they are hot, this may be why.

[flaVius]

Re: Help troubleshooting Dell laptop

are u going to attempt the replacement?

[arneson]

Re: Help troubleshooting Dell laptop

Yes, as a test of my soldering skill I removed what I thought was this forty pin surface chip. Turns out it has 41 pins, the entire bottom substrate is pin 41, gnd.
I was succesfull with this experiment, took very little time to remove and replace. The other board ended up looking like I'd never been there.
This was the most difficult soldering I have attempted, but it worked.

[linuxguru]

Re: Help troubleshooting Dell laptop

Wow - way cool. That's way beyond my abilities to diagnose/replace. However - why are these power controller chips failing? Are people attempting to install desktop (non-speedstep/mobile) P4 chips in these systems, causing the power controller to overheat?

One of the things I liked about the Inspiron 1150 was that I could buy the $499 Northwood Celeron system from Dell Direct (with some free upgrades thrown in as well), and replace the CPU with a Northwood mobile P4 snagged off Ebay for a song. I carefully chose the Northwood mobile P4 2.66/533 for this experiment, although there were the 2.8 and 3.06 also available - the main reason being the lower power dissipation of the 2.66. The experiment worked fine, and I got a Northwood Celeron mobile 2.60/400 as a freebie out of it - which works fine on most desktop P4 boards, as well.

It looks like this trick will also work with the Dell Yonah notebooks with Core Solo CPUs now being sold for $899 - however, I will wait for a while to snag one at for lower price points once Merom is introduced.

[flaVius]

Re: Help troubleshooting Dell laptop

Good to hear that it worked out. I think ill give it a try.

[arneson]

Re: Help troubleshooting Dell laptop

I looked really closely at the Heatsink fan assembly of thr Celeron and the P4, they are different.
First one of them has A1 stamped on it(celeron) , the other, A2 (P4).
I think that looking at the spring loaded mount, the C clip thread limit is set differently because the chip core depth is less for one than the other.
One also feels heavier but not sure about that.
This computer is not meant to be used on a rug or in bed.
It's a small vacume cleaner,
and if any feet are missing, replace them, this design needs ground clearance.

[linuxguru]

Re: Help troubleshooting Dell laptop

I looked really closely at the Heatsink fan assembly of thr Celeron and the P4, they are different.
First one of them has A1 stamped on it(celeron) , the other, A2 (P4).
I think that looking at the spring loaded mount, the C clip thread limit is set differently because the chip core depth is less for one than the other.
One also feels heavier but not sure about that.

I'd guess that the P4 heat-sink might have more copper and would therefore be heavier. The bit about the clearances being different has me only slightly worried - the P4 has been working fine in place of the Celeron for about 18 months now. However, I cleaned off the white TIM goo and used Arctic Silver 3 instead. Also the heatsink seemed to fit quite flush and the lock screws tightened up gently and cleanly with no alignment issues - only time will tell if the upgrade is durable. FWIW, complete heat sink assemblies have also been available on EBay, so that may be the way to proceed.

In other related news, Dell has a bunch of Yonah-based dual-core notebooks, including ones with 15" and 17" TFT displays, at very competitive prices. Those deals may get even sweeter when Merom is announced.

[arneson]

Re: Help troubleshooting Dell laptop

Dell has a bunch of Yonah-based dual-core notebooks, including ones with 15" and 17" TFT displays, at very competitive prices. Those deals may get even sweeter when Merom is announced.

Pisser .. I spent so much effort on these 1150's, then saw the new ones so cheap.