Kitamura Computers (UK) Support

Welcome to the support forum for customers of Kitamura Computers UK!
It is currently Fri Feb 28, 2020 7:45 am

All times are UTC




Post new topic Reply to topic  [ 1 post ] 
Author Message
PostPosted: Sun Jul 22, 2007 1:30 am 
Offline
Administrator
Administrator

Joined: Fri Feb 02, 2007 5:06 pm
Posts: 203
Location: Manchester, UK
Many customers, friends and relatives have come to me many times since 2003 regarding problems with their Dell Inspiron 5150 laptops. I recommended them back then, as they were, and still are, very very capable machines. There are a few official design flaws with the Inspiron 5150, but these are nothing that can't be fixed.

I run a couple of these machines at home, and in the office, and was involved in the Lundell Settlement, with my wife Kassie's 5150, which was bought from the US. Below, i'll outline a couple of these faults, and how to rectify them:

Battery charge light flashes orange & green

This issue is not a fault, but has worried many of my customers and users. When the laptop is used on the battery, usually from fully charged, until the battery is depleted, then the laptop is brought back to the mains, the battery flashes 4 times orange, then steady green for a second. This is the internal thermal protection (ITP) circuitry. The battery is too hot for the charging system to charge it. The machine runs from mains, and once the battery cools down, starts charging.

This procedure is detailed in the Users Guide, and also in our technicians Service Manual, available from Dell.

Laptop constantly shuts down

This is one of the design faults involved in the Lundell Settlement. A plastic prong holding the PCMCIA slot cover in place starts to push against a chip on the motherboard over time, causing the chip to come away from its solder pads on the motherboard, causing intermittent contact, and a short, shutting the machine down. The problem has been known to get worse and worse, until the machine no longer starts, causing extensive electrical damage.

It can be fixed, but once the problem starts, even if you catch it early, it is too late. Below is a diagram of the affected area:

Image

To fix the problem, follow my steps below:

1. Turn off the machine, remove the battery, and mains, and any connected devices, and turn the machine over, preferably on a piece of foam, or a newspaper, to prevent scratches.

2. Remove the PCMCIA cover labelled 'C' by unscrewing the single captive screw, and pulling up on it. The screw is held in to the cover, that's why it's known as a 'captive' screw. Once removed, turn it over, and you'll notice two plastic tabs. Using a sharp knife, or by simply snapping them off with your fingers, remove the plastic tabs on the cover. This will stop them pressing onto the chip and damaging your motherboard.

You only really need to remove the one that is directly over the chip, but i always remove both, all they really do is give extra hold to the cover.

Getting it repaired by Dell is getting more and more unlikely, as these machines are officially discontinued, but if you purchased an extended warranty, there could be a chance they may repair it. The Lundell Settlement only applies to the US.

For more information on the Lundell Settlement, visit http://www.lundellsettlement.com

Fan spins then stops, before spinning up and running normally

Sometimes the CPU fan will spin for less than a second, then after a 2 second delay, spin up and continue running. This is not a fault, just the fan driver chip linked to the thermal control module, "pinging" the fan to make sure it is responding. The fan has an RPM sense facility, which reports its speed. When the fan is running, it sends out pulses on the sense line, and the controller can determine the fans speed, by the frequency of these pulses. On the 5150, the controller sends full voltage to the fan for less than a second, and reads the return speed. It then spins the fan up fully, to cool the CPU, and turns it off again when the temperature reaches 50 degrees C.

Any failure of the fan would result in the machine shutting down before the temperature got too high.

"AC Adaptor type cannot be determined" message at start, and machine runs on battery

This is a problem that many Dell users blamed on the motherboard, but this is not the case. The 5150 determines the wattage of the power supply by the amp rating, as each power supply (90w, 130w and 150w used on the 9100) has a different amperage. If there is a slight fault inside the power supply, the power regulation circuitry derails the laptop onto battery, to prevent damage, because it doesn't understand the signal from the PSU.

Try a different power supply, the problem should go away. Sometimes removing all power sources for 40 seconds, can reset it. It can also happen in these circumstances, which require repair:

1. The power circuitry that regulates and distributes power to different areas of the motherboard inside the laptop is faulty.

2. The power socket on the motherboard is damaged. The tiny centre pin has a very fragile leaf spring pin clamp inside the socket, and with excessive use, becomes damaged, resulting in an inconsistent connection, causing the AC adapter to not be recognized, or for the laptop to switch constantly between battery and mains. Eventually the laptop will stay on battery until turned off.

Laptop overheating

This is a serious design flaw, and not as easily remedied as the above fault. The heatsinks in the 5150 are inadequate to the cooling of the laptop. The heatsink is designed in such a way that dust rapidly collects in the heatsink. The heatsink is not very easy to remove, and requires the top half of the laptop, including the display assembly, keyboard, and palmrest, to be removed.

Even then, once the heatsink is removed, and the fan removed, getting the dust out, which is usually a big thick chunk, if the laptop has never been serviced, is not easy, as the top cover of the heatsink cannot be removed, unlike some other HSF assemblies.

If you feel this is your problem, we can help you. We can fix this for you, for just £10 inc VAT.

Leave us a ticket in our helpdesk, at http://www.kitamura-computers.co.uk/helpdesk, leaving as much detail and contact information as possible.

We are experts in the field of laptops, and can fix almost any laptop.

Update 20/10/07:

My wife's 5150 has been behaving strangely recently. When it is on mains, and the battery is in, it goes off the mains, on to the battery. I originally thought it was Kassie's PSU, as it did start cutting out randomly, but upon replacing it, the problem reappeared after a week, and it is still doing it.

I've bought a new motherboard, i bought it with the new PSU as a package....and didn't really want to use it yet, as Kassie uses this machine a lot, she's a DJ, and uses it at her Martial Arts school, and at college, and the only way to stop it and get it back on the mains is to turn it off completely, or put it into Hibernate, then switch back on.

I think it may be a heat related issue, as it only seems to do it when running really hot, but i don't want to rule it out.

If you've had this problem, let us know!

Update 3rd December 2007

I've used the new PSU as part of the package, and it worked fine for a couple of weeks. Now it's started up again, so i can confirm it is the motherboard, or the DC power management/regulation system. It trips to battery when cold too, and it is getting more and more frequent. It's a shame too, as the board hasn't been in long. The laptop is used a heck of a lot, but i suppose these things happen.

If you need advice about this particular problem, get in touch, and we'll work things out.

Update: It isn't the board itself, but the DC jack, the centre pin leaf spring is knackered, and the jack itself is a sealed unit almost, so it has to be replaced. There's a lot of pins to solder, and they're very tiny, so i suggest referrring things like this to us, as we have the equipment, skills and training to do the job to Dell's factory specifications.

This is one of those problems that manifests itself as something else!

_________________
Regards,

James (Kitamura Computers Director)

james at kitamuracomputers dot com


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1 post ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group