Gpu reflow gone bad?

[mbsurfer2018]

Hello. I have an Toshiba C55D- A5380 laptop that was not displaying video. I connected the machine using the hdmi and vga outputs with no results. I checked and replaced the ram but no results either. Then I decided to reflow the gpu using an 858 D rework station machine and a no clean flux paste that I purchased on ebay. It was my first reflow. The first try showed no results with a black screen. The second time, I applied a little more heat and waited a little bit more while heating. Now I still have no video but the fan is not running when I turn the laptop on. The motherboard doesn't look burned and when I took out the ram, I get the bios codes. Did I damaged the motherboard, the south bridge? Did I damaged the fan?
Please help I'm a rookie repair guy.
Thanks

[brethin]

Re: Gpu reflow gone bad?

No video doesn't mean a instant reflow.

[mcplslg123]

Re: Gpu reflow gone bad?

@Brethin is right. Reflow is the last recourse after you have checked all lines thorougly.

Btw, it seems you have overheated the gpu and damaged it. Nothing wrong with 858D hot air gun-thats suitable for the job.

[MJ-meo-dmt]

Re: Gpu reflow gone bad?

Check with a new CPU if its not embedded... the LVDS converter as well(tho this is aimed for the internal screen, check for all the required voltages and so on, maybe rework the ram slots..

Hell it could even be a shitty BIOS or BIOS Chip, hell it could be some little shit resistor somewhere even :P haha its a rabbit hole........

Like the guys above mentioned you don't just reflow... reflow is harsh and if done wrong (possibly your case) you can destroy the chip. Also don't always assume the GPU is faulty because in most cases the First VGA/display device on default is actually or usually the HD Graphics you get in the iCore's and in other cases the PCH is strapped for the LVDS/external display lines... best would be to try and find a schematic for it or something close to that model so that you can see how its put together and then work from there....

In fact go grab a schematic of something in that range could be anything(other make) and get your self up to speed to know how the things connect.

#Edit: and for reflows I found that a liquid flux F959 works just fine. *hint* When busy reflowing with this type, if it feels like you want to cough dont! :P its a trap

Good luck!

[mbsurfer2018]

Re: Gpu reflow gone bad?

Hello and thank you very much for your time and good advice guys.
I made the GPU reflow because after checking the ram, cleaning the heat sink and fan,(it had a lot of dust and it was clogged with it), applying thermal paste and connecting via external rgb, it was dead no video.

I'm a rookie repair guy and that what I was told to do in a seminar that I took a couple of years ago and by watching youtube videos. But you and the other gentleman are correct, the reflow option should be the last thing to do and I should have practiced in other boards first, but what is done is done and now I will work for the solution.

I didn't know or forgot what the LVDS converter or cable was, and thanks to you now I do. I'm not a full time repair guy, is just now and then. What is the PCH?.

Well, I will try to get the info about the board circuit design to learn about the connections but as @mcplsg123 said, its possible that I burned the GPU and maybe that's why the machine powers up but the fan doesn't start. If I remove the ram , I get the bios ram error codes but no video and no fan.

Here are some specs of the board and some pics after reflow. You can see on the GPU still has non clean reflux paste.

Model Name: C55D-A5380

Processor3 and Graphics4:

AMD Dual-Core E1-1200 Accelerated Processor with AMD Radeon™
HD 7310 Graphics
o 1.4 GHz, 1MB Cache
o AMD A68M Chipset

[IMG][/IMG]

[IMG] [/IMG]

Can this be fix if the GPU is burned?

The CPU is a BGA.

Thanks a lot and have a nice day.

[mbsurfer2018]

Re: Gpu reflow gone bad?

Thanks bro for the advice, please see my last post.

[mbsurfer2018]

Re: Gpu reflow gone bad?

Thanks for your advice, please see my last post.

[mr.Data]

Re: Gpu reflow gone bad?

I have repared a lot of GPUs with reflowing but when it works, it only does for a short period of time in 80% of the cases.

I would strip the entire motherboard down and put the motherboard in the oven at 200 degrees for 10 min and then let it slowly cool down with the door of the oven slightly open. This works in 80% of the cases but only for a couple of months.

[ktmmotocross]

Re: Gpu reflow gone bad?

reflow always come back. reball or nothing

[mbsurfer2018]

Re: Gpu reflow gone bad?

Thank you very much.

Maybe I'll do the oven procedure, I have heard about it but it looks kind of dangerous for the MB. I'll look for an used MB just in case this fails.

[mbsurfer2018]

Re: Gpu reflow gone bad?

Thanx

I don't know how to reball, I will have to practice on another board first, this one is my niece computer. I'll study the procedure thanx again.

[mbsurfer2018]

Re: Gpu reflow gone bad?

Update :

I made a third reflow and now the fan works but still no video. I started first warming up at 160 c for a minute, then went up to 190 - 195 for the second minute and then went up to 220 for 40 or 60 secs more.
I still have no video but I have to check again if it outputs video from the rgb port. I also replaced the ram but still no results. I don't know if the ram I used to test it is defective but if I boot it without it I get the bios beeps so I suppose the ram stick is good.
I will try to get another ram to test it again, also I got the schematics of the machine and I'm working on it. Maybe it's a bad screen or video plug/port. I'll guess I will have to get some spare parts to be sure. i also checked for continuity with a multimeter and it seems good to me .

thanx

[mr.Data]

Re: Gpu reflow gone bad?

It sounds to me that the GPU has died. Replacing the GPU would be an option but its a diffecult process.

@ktmmotocross
Reballing doesn't do the trick in most cases because it doesn't have to do with the connections. It is mostly a bad GPU and with a little heat the chip works sometimes but like I said, its mostly a temporary fix.

Reballing on the other hand is only necessary when the connection with the MB is bad. This is almost never the case. Reballing is a tedious process, only do this when you are sure it has to do with the connection.