Asus Q502L does not boot up properly

[emadarion]

Thank you for sharing, very detailed, to see more times to remember

[tibimakai]

Still not done with this laptop. I have purchased a used board from the bay, installed a brand new Samsung ssd, installed Windows 10 and all seemed fine for a few days. I have put it away for a few weeks.
After awhile I have grabbed it, and it started acting up.
What's in a while would not "see" the ssd and would boot into BIOS. If I rebooted, eventually would boot and work OK for a while.
Now more often goes to BIOS, then in Windows.
Replaced memory, HDD even the small daughter board for the HDD, still no change.
Has the latest BIOS, all the updated, Windows 10 2004 and all.
Any suggestion what should I do with it. Sometimes goes into blue screen as well.

[tibimakai]

Nobody has encountered a disappearing HD situation, what could be?

[tibimakai]

If I plug in a 2.5" HDD it shows the Sata port 0 as Empty.
If I plug in an msata SSD, it shows Sata port 2 as Empty.
If I don't plug in any HDD, shows all Sata ports Sata 0, #1, #2, #3, #4
They all show Empty.
What could be the problem here?
What controls the Sata ports? The CPU, or there is a separate Sata controller?
Any help would be greatly appreciated.

[tibimakai]

It stopped recognizing any HDDs.

[Duranitron]

if its not recognizing any ssd hdd try to clean the connectors. try to reinsert it.. try to boot using usb does it recognized the usb drive....do you happen to check the rtc battery maybe its way too low..

[tibimakai]

I have even replaced the hdd daughter board, so it is hard to believe that the connector is causing these issues.
I will check the connector, just in case.
It recognizes a USB stick. Starts installing Windows, but it won't find a hdd.
I haven't checked the battery, but it holds the date.

[tibimakai]

It's been a while since I have looked at this laptop, but I have just had a bulb turn on above my head.
The laptop hard drive, has to have a 12V supply as well, other than 3.3V and 5V supply?
I don't have it.
No matter what I try, HDD won't show in BIOS.
I would appreciate any help.

[piernov]

No, 2.5" laptop HDD don't use 12V.

[tibimakai]

What else could be, that no hdd shows up in the BIOS? 3.3V and 5V is there.

[tibimakai]

There is only the ITE IC and the CPU on this board. What could cause this issue?
BGA solder issue at the CPU?

[tibimakai]

Nobody can help?

[FrozenHaxor]

Most likely cause is the PCH part of the CPU is bad, it controls SATA I/O directly.

[tibimakai]

Can't be solder balls cracking?
Thank you, for your reply.
How "easy" is to replace the CPU?

[FrozenHaxor]

I have a BGA machine with optical system and it takes lots of experience to do it right. Intel CPUs are notorious for doing a "banana" and warping on cooldown, I avoid replacing them like a plague. I usually condemn boards that need this repair as it's not worth it most of the time, and new CPU itself will cost more than complete used working board in this case. If you suspect cracked BGA soldering then you could do a reflow, but all of the glue needs to go before doing it, and you still need a BGA rework station to avoid warping, especially on cooldown. If the laptop wasn't dropped and there was no physical shock to the mainboard, it is most likely internal PCH fault and they are notorious for such problems, even Intel admitted so years ago.

[tibimakai]

Most likely I won't reball the CPU, just reflow it.
What is interesting, that initially when I got the board from Ebay, it was working great, I have installed Windows, and it worked.
After a while, it started to act up, sometimes it would not recognize the hdd, but a reboot took care of that. This started to become more frequent, until it would not recognize it at all.

[FrozenHaxor]

Does your HDD connect directly to the mainboard via ribbon or is there a daughter board with connector that mates to the mainboard?

[tibimakai]

Daughter board. I have already purchased another one, and it is still the same issue.

[FrozenHaxor]

Did you inspect the other part of the connector on the mainboard? Some Asus boards are prone to failures of them causing odd issues. If it's okay then it's a PCH problem.

[tibimakai]

Yes, I have when over with the solder iron.