two broken motherboard= one working motherboard?

Jackovarian

I could be in the wrong section here, but the forum list page is so vast I cant find where i want to go!!!!

so,
I have a laptop motherboard, which works fine, except that the vram is a bit weird and it wont work the laptops lcd. but it will work an external monitor fine.

I am hoping to get another board from a machine of the same model. this machine does not even power on. The problem with this machine is unknown.
I am thinking it could just be a power board issue.

anyways, i obviously cannot replace the vram on my own as it would be too risky and i'd probably end up with two messed up boards!

so, any ideas? would it be worth getting the second board and trying to fix the dead one?


:eek:

Jackovarian

ok... that was helpful!

anyways,

does anybody know if the solder on small components has different heat rates than normal electrical solder?
i dont want to burn out components with an extremely hot soldering iron.

also, onboard chips, are they easy to remove? or would they burn out with a normal soldering iron? I mean would you need a spot soldering iron to minimise the heating time between contacts? meaning less heat across the chip...

anybody?

am i alone?

ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh!!!!!!!!!!!!!!!!!!!!!!!!:eek:

zilog_jones

How do you know the problem is with the VRAM? I'd say changing any components on a laptop motherboard would be a pain in the hole - have you looked at it? If it's fairly recent they could be BGA chips...

astrofool

To be honest, it doesn't sound like you know enough about motherboards to know what to do. VRAM hasn't been used for many many years, and if you're confusing it for the graphics RAM, then the fact that an external monitor works fine, puts that idea out the window. More likely a problem with the LCD screen, or the connection to the LCD screen.

Jackovarian

well, i know a small bit, i never claimed to be brilliant!

the tech repair shop i took it told me it was the vram.

obviously they just said that in passing. they meant graphics ram...

ive tried to get a new board for it, cant be done. they are too expensive, so ive got two boards now...

the question was, is it possible to solder new parts on, whether i'm qualified or not!

AlmightyCushion

But it's not the graphics card if it works with an external monitor. It must be the screen, inverter, cable connecting the graphics card to the screen.

Jackovarian

thats what i thought before i sent it off for repairs. so i bought new cables, inverters. the only thing i would get is a white screen.
oh, also tried a different screen. which i know was working.

its a strange problem...
apparently the power running through the graphics ram was fluxuating strangely.

yet it can still play doom 3 full whack with an external monitor! so i dunno!
id imagine there would be a loss in performance...

astrofool

Would have been cheaper getting a new laptop.

To answer your questions, yes using a normal soldering iron will likely fry the chips. If they are BGA based, they're completely impossible to solder manually.

Whoever you took it to is talking out of their arse, I don't know any repair technician in the world that would monitor voltage over graphics RAM when troubleshooting.

You're really thinking about this from an electrician point of view, when whats happening is many levels above that.

What laptop is it, what cables and inverters did you buy for it?

mathias

The only way to work with these boards is with a proper surface mount solder kit , which instead of an iron uses focused hot air and sucker pens to lift the components , then you would have to clean the "lands" , apply solder paste , ( not like ordinary solder ) and re apply the hot air.

This can be done with small quad lead components only , dont even try with any kind of grid array component , its not possible !!

In most cases these boards were never designed to be re-worked , they are usually replaced only , not reworked. ( Unless its a very minor fault of course )

Jackovarian

thanks guys.

yeah, i kinda thought that it was pointless monitoring the current flowing across them. of course they are going to fluxuate!

yeah, i kinda guessed i'd need a diff set up to solder it.


ahh i'm not that pushed. i mean i'm going to have a look at the new board and see, but i'm not going to needlessly fry both boards!

its an acer 5021wlmi.

i replaced both screen ribbon/cable and inverter, but they had the same results as the others. i mean, it was hardly gonna be the inverter as the screen lit up!

its very frustrating...
what would normally cause a screen to show up only white???

i would have reckoned a bad cable. it would mean a lack of info getting to teh screen.

the screen would differ in brightness sometimes also, and have lines hz and vt on it. different colours.

any ideas?

could just have been two fecked screens?

zilog_jones

My friend had a similar problem with his Acer laptop (slightly older Turion-based one) when it warmed up - screen going white, green in weird places, etc. He sent it back (was still under warranty) and it seemed OK but I think it started happening again after a while. Then it got stolen (after chaging the keys to Dvorak lol)...

If the problem with the other board is just the voltage regulators or something like that, that would be much more plausible to fix - if you can find out exactly what the problem is of course.

gamer

put it in adverts.ie computers for sale,laptop,only works on external monitor,plus spare mobo,parts, then with the cash,buy another laptop ,you,ll get a fine laptop adverts.ie 4 250to 300euro ,its possible ribbon,video cable from mobo to laptop is simply unplugged from mobo video pcb interface.BUT i dont think its safe 4 a newbie to go opening laptop,theres nothing wrong with mobo video,otherwise you cud not play games on a monitor,if you have a techie friend ,maybe ask him to check internal cables,connections.

Jackovarian

first off. stop being patronising.

secondly, i have had a friend look at it. Ive had repair centres look at it. I realise it might seem worthwhile to everybody else on here to sell the thing on, but being honest, I like challenges. If i wanted to flog this thing on to somebody I would have done it already.

As much as you might like to think it, I'm not a newbie.
anybody would think it was a mortal sin to open up your own laptop and have a look to see what the problem is! Its not like its in warranty!

god sake, i asked for help, not to be treated like a two year old with my first feckin vtech laptop!


and by the way, if you had read any of the posts above you would have seen I have tried everything you said. so hows about next time you read the thread rather than just reading the title and coming on with your master computer know how.

Jackovarian

zilog_jones wrote: »

My friend had a similar problem with his Acer laptop (slightly older Turion-based one) when it warmed up - screen going white, green in weird places, etc. He sent it back (was still under warranty) and it seemed OK but I think it started happening again after a while. Then it got stolen (after chaging the keys to Dvorak lol)...

If the problem with the other board is just the voltage regulators or something like that, that would be much more plausible to fix - if you can find out exactly what the problem is of course.

out of interest, would there be any way to flash the bios of the gfx chip?
i dont think it has any inbuilt bios or firmware like, i'd imagine it runs purely from drivers, and some form of autorun from the laptop bios?

i have updated the laptop bios to the most recent available version btw.

irlrobins

Behave gentlemen

*Taps ban stick*

zilog_jones

Jackovarian wrote: »

out of interest, would there be any way to flash the bios of the gfx chip?

Don't know TBH. I know older AGP and PCI graphics cards had an apparent BIOS (people used to flash them to get them working in Mac's IIRC). Unless this issue has only arisen after updating the BIOS, drivers or whatever I don't think it'll fix anything though. I'd say it's a hardware failure somewhere. The occasional vertical/horizontal lines and the fact it works grand through the VGA out would suggest there's something wrong somewhere along the line between the output from the graphics system (but far enough to get to the RAMDAC ok - I think that may be integrated into the GPU these days though) and the input to the control board or whatever there is that makes the LCD panel work. I really don't know much about modern graphics/laptop architecture to say any more.

Is it possible to get schematics or a service manual (if such things exist for laptops)?

I still think it could be more worthwhile getting the other board to work if it's just a power issue - finding out where the power goes would be much simpler. But even then you're still working with crappy tiny little surface mounted components and a multi-layered PCB...

Jackovarian

the only other thing i can think of is that its the screen.

i mean, the repair place had no way of properly testing it. they would have had to have a similar laptop, which they didnt, or some form of vesa board to drive the screen or something. which is far too much hassle. so i dont know.

i'll be getting new parts soon hopefully anyways. so ill post back what happens.

one more thing. if the screen hinges were broken, and the ribbon torn from pulling on the mobo, do you think their would be damage to the ribbon connector on the mobo? it looks fine like, ive examined it closely and seen no shifting in placement or crack in solder or platics. but could the connector pins have been cracked at the base, where i can see, and so cause loss of info?

I bought this as a fixer upper btw!


milk was a bad choice.

gamer

depends on what you paid, if i paid 65euro, 4 a laptop ,id take it apart ,take out mobo,put it back 2together just 4 the crack ,say its 7years old,the repair shop wont have ,parts,wont try 2 get parts 4 it, they may judge it may take 5hours to fix it,they r not going to ask you 4 200plus vat,2 fix a laptop, dont want 2 be patronising ,it sounds like a tough job,1st time opening a laptop, to desolder ,and replace a chip,troubleshoot mobo,you,d need special tools for that.
post model name,eg dell inspiron 1100.google laptop name here schematics.
how to troubleshoot laptop name here ,how 2 replace motherboard.
YOU could replace ever mobo chip and it still wont work, theres various diagnostic progs that,ll test a laptops components, my dell 1150 has ,inbuilt diagnostics,i go to bios, run diagnostic,it tests mobo components,chips etc.
IF its model x the parts could be hard to get,or too expensive.in shops now you can buy a laptop 500euro brand new 12 months gaurantee.

Jackovarian

thats cool. sorry for being pissy.

its an acer aspire 5021wlmi. turion ml-28 (i think) 1.6ghz processor.
its running an ati radeon 700x on a pci-e expansion slot (onboard). its the 128 meg model. theres a 256meg model which runs at 400mhz core. this ones slightly slower.

the problem is though that acer have released a couple of new bios's for this machine as the graphics ram was getting too hot on the 64meg models. so, i dont know if there is a link here. but i'm reckoning there could be.


i havent spent much on the machine either. I'm not gonna lose big if it breaks like. i just want to try fix it. ive taken laptops n pc's apart before. just that i wouldnt have tried soldering, unless it was for something really simple, hence why i came on here!

oh, and buying a new laptop spoils the fun of it!

gamer

google acer 502mli troubleshooting ,diagnositics ,repair 502mli ,schematics ,upgrading 503mli acer ,but you,r hardly gonna buy special tools just to fix ,1pc, could be ribbon cable ,loose,disconnected ,from mobo interface ,or video cable to screen lcd, loose , look at adverts.ie service,theres a boards member,fixs laptops, dublin, or post on laptop forum.look at acer ,website,support, troubleshooting 502mli, video,display problem,theres programs that diagnose laptops ,mobos ,test the chipset and programs for testing memory too.
theres loadsa people would buy that laptop,run it off an external lcd ,you ,d get a good price for it.