HP 6735s blinking orange light

[John_F_L]

Hello,

I have an HP 6735s (6050A2235601-MB-A03) which came to me with 5 blinks on keyboard. I thought, as on other laptops like this one, GPU problem. I reflowed the GPU for a very short of time, and had picture on screen. So I told the customer, I have to reball the GPU.
After the reball, the laptop won't start at all. The orange light on the charging port blinks for 12times and then off. It's not the charger because with the same one I use me HP laptop.
One more thing (didn't check it before) is that on the VGA coil I have 1ohm resistance to ground. Is that possible? Or after the reball the GPU died and shorted???
If nothing of all these, what else can I check??

Thank you.
John

[dellxps15]

Re: HP 6735s blinking orange light

sometimes a vga mosfet can fail too, but power supply should turn off. could also be a bad gpu or bad solder bga. if u can disconnect the coil for vga or if there is a pj jumper to desolder to isolate the vga and check if it power on.

[John_F_L]

Re: HP 6735s blinking orange light

I tried that, and it won't power again.
I also upload the schematic for better help.

Forgot to mention that I have 3.3V and 5V on the board.

[dellxps15]

Re: HP 6735s blinking orange light

replace rs780 with a new one.

edit: before replace bga try flash bios again.

rs780 are well known to fail, and for best result is good to put a new rs780 and a new southbridge. that will make notebook last longer.

[John_F_L]

Re: HP 6735s blinking orange light

I haven't dont any work on the southbridge so I don't think I'll change it. But I will find and order a new Ati chip. Probably the temps on the reballing destroyed the chip.

I haven't tried bios yet, so i'll try that first thing tomorrow.

[John_F_L]

Re: HP 6735s blinking orange light

I reprogrammed the main bios and the same thing happens.
Maybe it is the EC but I don't have a known good one.

[Th3_uN1Qu3]

Re: HP 6735s blinking orange light

1 ohm on RS780M/880M Vcore is too low. Should be in the range of 8-12. Need to replace chipset.

[ktmmotocross]

Re: HP 6735s blinking orange light

u did not wrote if u have NB or NB+GPU

[John_F_L]

Re: HP 6735s blinking orange light

after a month the new BGA came to my hands. Now the laptop starts up, I can see the LCD backlight on and immediately going off and then 5 blinks on keyboard. I have already tried to reheat the BGA and even reball it again. The same thing.
And also programmed the bios with the original dump that the laptop came to me.

[caspian]

Re: HP 6735s blinking orange light

what is the BGA machine that you used? How old is the chip that you bought?

[spleenharvester]

Re: HP 6735s blinking orange light

I have also gotten 5 blinks on this model after accidentally touching a component next to TPS51120 before, so it's not always GPU I don't think. Never figured out where the fault was.

[John_F_L]

Re: HP 6735s blinking orange light

the chip was 2012+ as the seller wrote. I'm using the LY IR10K.
What I found after searching through the internet, is that this might be a CPU error and not a motherboard failure error. If I remove the CPU from the board I have the same blinks and some people (on videos on youtube) said that this is not a 5 blink error but 1 blink five times so CPU error.
I don't have a replacement CPU to test.

[caspian]

Re: HP 6735s blinking orange light

since this is an old laptop, every part of it could be faulty, such as GPU, CPU and southbridge. to find out, you have to do more tests and consider the symptoms.
is there any time interval between every two rounds of 5 blinks? or how many times the 5 blinks are repeated?

[John_F_L]

Re: HP 6735s blinking orange light

the five blinks are not repeated. the interval time is around 3 seconds. and also the orange led is blinking every 1-2 seconds.
I have measure for any short to ground on the big coils, all look fine. Also I have all the voltages that are shown on the diagram (page 4 of the manual).
I tried another RAM from a different working HP laptop. I tried again another bios dump.
And still the same.... five blinks from Caps Lock.

[caspian]

Re: HP 6735s blinking orange light

if there is 3 seconds between consecutive blinks, they are not considered as 5 consecutive blinks. they are just five separate blinks. However, a 3-second interval is too long and seems strange. Since you said you got picture after GPU reflowing, probably the problem is GPU or around GPU. Did the picture stay stable at that time?

[caspian]

Re: HP 6735s blinking orange light

is the battery connected that it shows orange blinks?

[dellxps15]

Re: HP 6735s blinking orange light

make a good picture of the bga soldered. did it went down at around 190 ° celsius or 230 celsius ?

if it had leaded balls then it was refurbished...

5 blink is general failure.

bga get hot ? cpu get hot ? voltages on each coils ?

[John_F_L]

Re: HP 6735s blinking orange light

it went around 200 for the bga to get soldered (my thermocouple never works fine, always shows less, at around that temperature I desolder all the factory BGAs), so I assume that it is not refurbished.
Voltages on coils are:
L1006 - 5V
L1016 - 3,3V
L1126 - 1.21V
L1028 - 1.12V
L1039 - 0.92V
L1040 - 1.83V
bga and cpu get a bit hot, but I try it without the cooler.

[ziouneh]

Re: HP 6735s blinking orange light

Hi guys,
I am happy to join the community.. and to have you as partners..
thank you for any help in advance..
I have a problem: I have an ASUS with F5R motherboard.. It doesn't accept any driver for
the onboard graphics display card ATIRadeon xpress 1100..
I appreciate any help..
thanks

[ziouneh]

Re: HP 6735s blinking orange light

check the RTC orbios battery.. it happened to me once.. the motherboard doesn't turn on without a good battery 2032.. or just try to replace the IO chip.. Never attempt to make any repairs with the RTC battery onboard.. it can easily destro your IO