Acer 5742G dead after stress test

[JohnSwe]

Looking for advice..

Acer Aspire 5742G started to power-off due to overheating.
Now it wont start at all, external power or batt.
It shows no lights when connecting power (no sign of battery charging).

I guess something has fried around the power-circuit...

The last thing I was doing was a small stress-test...

(The external power is working with another Acer)

Mb is "NEW 71 LA-5893P"

Someone that can lead me on the way trying to find whats got fried?

[dellxps15]

Re: Acer 5742G dead after stress test

try flash back ec bios.

[JohnSwe]

Re: Acer 5742G dead after stress test

How? It's stone dead...

[Th3_uN1Qu3]

Re: Acer 5742G dead after stress test

You need to take the laptop apart and use a BIOS programmer to flash it.

[RJARRRPCGP]

Re: Acer 5742G dead after stress test

Sounds like a faulty VRM or CPU.

[Th3_uN1Qu3]

Re: Acer 5742G dead after stress test

Don't think so. A short on the CPU VRM would still have the board light up the battery charging LED.

[sopik78]

Re: Acer 5742G dead after stress test

Agree with Unique, do flash bios and ec first, than we'll see. I had three these laptops with the same problem and flashing helped.

[JohnSwe]

Re: Acer 5742G dead after stress test

Ok sounds doable...

So I remove the bios and reprogram it using an external writer?

Any tip on a good eeprom(?) writer?
And where to find downloadable bios'es?

[JohnSwe]

Re: Acer 5742G dead after stress test

So a faulty BIOS can make the charge-light not come on? Is not the charge circuit a more hw issue..?

[age80]

Re: Acer 5742G dead after stress test

Here's the schematic in case it's not a BIOS problem

[sopik78]

Re: Acer 5742G dead after stress test

Try this dump, it worked well

I use EZP2010 external programmer, cheap chinese one and I am fully satisfied

[JohnSwe]

Re: Acer 5742G dead after stress test

Thanks!

Will any on these do for the programming:
http://www.ebay.com/itm/251369833299
http://www.aliexpress.com/item/FAST-...713696363.html
(Gonna take some weeks to get them to Sweden..)

So I flash both BIOS and EC, right?
BIOS = SPI ROM = U18 ?
EC = U31 ?
(Im gonna need a smaller soldering iron for this job.... Desoldering is PITA?)

Please correct me:
Content of bios_new71.rar is:
KBCA121A.rom = EC
NEW70121.fd = BIOS

Are there different BIOS dumps for different graphic cards on the mb?

[sparker1]

Re: Acer 5742G dead after stress test

A heat station is sometimes easier than a soldering iron. Mask off the area with heat resistant tape and de-solder with the heat station Re-solder the same way.

[sopik78]

Re: Acer 5742G dead after stress test

Thanks!

Please correct me:
Content of bios_new71.rar is:
KBCA121A.rom = EC
NEW70121.fd = BIOS

Are there different BIOS dumps for different graphic cards on the mb?

Correct.

I used these dumps for nvidia model, but should work on ati as well

[Agent24]

Re: Acer 5742G dead after stress test

A heat station is sometimes easier than a soldering iron. Mask off the area with heat resistant tape and de-solder with the heat station Re-solder the same way.

With something like this, hot air is pretty much the only way.

[JohnSwe]

Re: Acer 5742G dead after stress test

Thanks again.. I also have the Nvidia so that should work then.

Is that CH341A programmer above ok?

Can someone confirm that I've got the right chips on the mb, U18 and U31 ?

[Agent24]

Re: Acer 5742G dead after stress test

That CH341A programmer lists MX25L3205 and MX25L1005 as supported, which according to the schematic, your board uses.
You may wish to verify the chip part numbers on your own board too though, but if they are correct, it should work, assuming the software for such a cheap programmer is not full of bugs!

How are you going to connect the ROMs to the programmer though? Unless there is an ICSP header, you probably need a 150 and 200 mil SOP8-DIP adaptor sockets for the programmer. Also some way to remove the chips without destroying the board. It can be done with a soldering iron if you are skilled and careful, but hot air is a much better idea.

[JohnSwe]

Re: Acer 5742G dead after stress test

Maybe something like this:

http://www.aliexpress.com/item/Quali...219537667.html

[Agent24]

Re: Acer 5742G dead after stress test

Yeah that would do it, although if the schematic is correct the main ROM is in a 200mil package so you would need both a 150mil and 200mil socket, one for each ROM.

Personally I'd buy from eBay too, I'm sure there are good sellers on AliExpress but I don't trust it myself...

[megaraider]

Re: Acer 5742G dead after stress test

While you wait for the programmer try reseting all BIOS settings to default.
Incorrect values (assigned or recorded, e.g. temperature, ...) might have been stored.
To archive this you have to look for a 4 points jumper located very close to the RAM door / socket, labeled "RTCRST" & "SRTCRST".
Short them all together.