Help! My charger light blinks when its in my Laptop. and my laptop wont charge - Page 2

Followup, and hopefully my last post in thread:

I replaced and installed the new DC jack, and though it doesn't make particular sense to me, I haven't had the problem since (approx 18 hours).  From what I can tell, the assembly looks like a standard, 2-conductor (i.e. one hot and one ground) jack (5.5mm ext., 1.7 or 1.8mm int, female) with no additional circuitry.  Four leads (two red and two black) come out the back, and loop through a noise-attenuating / inductor jammy (technical term), with no further circuitry apparent.  The leads (insulated 24-28 AWG, I'd guess) terminate in a 4-pin female plug.  I haven't multimeter'd it yet to check for resistance/continuity.

Looking closely at the inner barrel of the jack, a dozen small scorch marks on the plastic and metal are visible-- almost certainly small arcs that I'd heard if I connected the plug to the lappy AFTER connecting the transformer/brick to the AC.

Now I'm curious about the continuity and resistance.  I'll post when I get around to it.

For the record, the part I used cost $4.42 on ebay, with "free" first-class USPS shipping.  I prefer to buy from domestic (US) vendors-- no nationalism, just don't like to wait!-- so I likely could have gotten it for a few cents less if it had shipped from China.  I chose ebay vendor "meditechny", based on their 99.4% feedback.  

the item is # 400260231948, and the price DROPPED to $4.39!!!  I should demand a refund!!!

Nope, 100% satisfied, and I'll post the same on ebay.

step 1; chek output charge with multimeter, and the result  must 20V , 3A (normal)

step 2; chek plug in charge, ( laptop slot in charge)

step 3; fix it, or replace it

from eve digital service

I've had the same exact problem with my Acer Aspire 5552. After much monitoring, i have determined that it is simply an emergency "fuse" method used by the Acers. Basically when the laptop is overheating, it refuses to bring in more power (heat) to prevent the Lithium battery from exploding (which they are prone to do). A good method to allowing your laptop to receive the charge again is to put it in hibernation for 5-10mins and make sure that there is air space underneath as well as around your laptop.

     -I hope this helps! 

     -Luc (Lucskywalk75)

there's a short on motherboard component [ usualy the FET or MOSFET or capasitor ] in the power rail..you sould check every component in power block using the multitester to find the short component and replace it....

I bought a laptop 3 months ago, I ship it out of country. It came on first than it when off and each time we try to turn it back on , green light keep  blinking. Is it because the battery is not fully charge after 3 months?

I'm just about pulling my hair out with this one.

I have an Acer Aspire 7540 which will not boot up. When I say will not boot, I can push the power button and the laptop goes through it's BIOS load then looks to run Windows (I've even tried a Ubuntu disk in it too) and lasts for about 10 secs and click, off! It does this repeatedly.

I have replaced the motherboard!

I have replaced the AC power source.

Still exactly the same.

I took the fan off the heatsink and saw there was quite a lot of dust gathered by the exhaust slots. Cleaned all of that out but still the same.

If I try to boot into Ubuntu I get a Critical Temperature error message just before the laptop shuts off.

I thought this would happen with the amount of dust on the exhaust but this is now completely clean.

I simply don't know what to do next. As you may have guessed, I'm fairly competent with stripping the unit down as I have replaced the motherboard, including the AMD CPU and heatsink and fan, but this blasted thing just does exactly the same - shuts down itself after about 10 secs.

The fan does come on after about 5 secs but then the whole laptop just clicks, then off!

Any further ideas??

My apologies for the triple post. That was an error on my part as I clicked on the submit button (twice) and nothing happened. I then press the preview button and then saved the post.

I'll try to remove the duplicates. Apologies again.

As regards the CPU, the CPU is the same CPU from the old motherboard but I have not used any thermal paste on it. I've never had to do that before on other motherboards I have replaced - is there something quite sensitive to Acer boards and chips??

Yes, bought some cleaner and new paste today so will give that a go later.

I did clean out the exhaust which had like a blanket of dust covering it, so that is all clear now. And the fan does come on.

Well, after all of that I managed to work it out.

I took the motherboard out again, clean the old thermal paste off the CPU and heatsink and then re-applied new paste. Re-assembled the laptop but same thing happened. It just switches itself off after 10-15 seconds.

I then compared the two motherboards to the most detail I could (the motherboard part numbers etc matched exactly!).

On the 'new' motherboard I noticed there was another chip adjacent to the main CPU which looked like it should have a heatsink on it but the main heatsink didn't go anywhere near it. I gathered that this must be causing the problem. I managed to repair the old motherboard (power socket) and re-installed that into the machine and it is working a treat now!

Not sure I want to do my research into why these boards are slightly different even with the same part numbers.

Here's a photo of the 'new' motherboard with my annotations of where the 'new' chip is and where the heatsink goes...

On the existing motherboard the chip on the left hand side doesn't exist. There are quite a lot of soldered ends in the shape of the square chip, but there is no chip there.

I'm wondering if it is some sort of enhanced graphics chip???