Compaq CQ56 has been a huge pain in the ass.
Some guy called me today about that CQ62 board i had for sale. If you remember, i fixed that board it a couple weeks ago by flashing the BIOS (after reballing produced no results). This board is compatible with several models including the CQ56 which he had. I only tested the board as far as "powers up, shows video" as i did not have the other parts such as keyboard, screen original cooler and so on.
He said he'd been quoted a pretty high price by a shop for repairing his board ($130), and that he would rather buy my board for $63 (plus $15 for installing the board, free installation if i get to keep the old board). His board still showed video, albeit with all kinds of fuzzy stuff over it. It still ran with the AMD display driver though.
I took the laptop apart and found something nasty. The NB did not have the thermal rubber on it anymore, there was just a blob of pretty dry white goop. He said he went to the warranty shop right after the warranty expired, and had it cleaned there. That was a couple years ago. Since then he's been taking it apart and cleaning it himself, but he said he never removed the heatsink or changed the paste. Alright, moving on...
He also had a Phenom II he wanted installed in place of the Athlon II it had. Okay no problem... As my luck would have it, my board worked great except one thing. The #!*$% board would give an error message saying that the fan wasn't working correctly on boot, and the fan would be maxed all the time.
I measured the fan RPM sensor circuit, and found it shorted. But it only had a pull-up resistor to 3.3v, and then it went straight into the KBC. F#!*. I put a lithium battery on the circuit and indeed, the KBC was the only thing getting hot.
Now, i would rather do a reballing rather than replace a KBC (especially for such a stupid issue), so i told him to leave the laptop here as it was getting late, and i'll fix his board instead.
I took the NB off his board and there was discoloration under the die, both on the chip and the board. Something told me that the chip is toast, but i reballed it anyway. I put it back on and it would crash when trying to load the AMD driver, only safe mode worked. I removed and re-installed it but same thing. I removed the undervolting resistor (yes, i'd undervolted it too), no change. I then took the board back out and measured the capacitors on the top of the chip, and some sections indeed measured shorted. This was confirmed later when i pulled the chip back out.
I believe the chip died during the desoldering process, so i could have caught it earlier on if i measured it. Oh well.
I had a spare RS880M so i reballed that one, lifted the original one from the board (again) and carefully cleaned the pads (again). I had some more solder mask scraping off but nothing that would make it short out. Soldered this chip on the board, it measured ok. Tried to power it on, nothing. No fan and just the wireless light on the keyboard lit up.
I thought that some flux had somehow made it in the CPU socket from my dirty hands handling the CPU and i was right. After brushing some IPA in the CPU socket, the fan turned on, but still no display. I plugged in my POST card and it seemed to be doing something, so i tried the VGA output. It worked. Hmm.
Then i thought i'd gave the display connector a good cleaning too, and guess what... We can haz video on LCD. AMD display driver now installed fine, and everything worked great. Hooray!
And undervolting it works as well. 
Another thing that needed some brushing was the touchpad ribbon, but oddly enough, the problem was at the touchpad side, not at the board side... I cleaned the ribbon well and flipped it around and now the touchpad works great too.
It's doing RTHDRIBL and Prime95 Blend test right now. I'll leave that running until i wake up.
IMO this thing doesn't deserve a Phenom, but hey, if that's what the guy wants... It's got an SSD in it too, and for what it is, it's not too shabby indeed, but i still wouldn't have put a quad-core in it. I get to keep the old Athlon II too and the price for the chip replacement will be quite a bit higher than $63 (but lower than $100+ he was quoted elsewhere), so i'm not complaining. But this was a LONG night.
Morale: Just because thermal pad/rubber is crap, it doesn't mean it'll work better WITHOUT it...
I have of course replaced the thermal rubber for the NB and used high quality paste on the CPU.
Funny thing, there's another CQ56 waiting for me at work tomorrow. But that one only needs the dust bunnies kicked out and the touchpad fixed.
He said he'd been quoted a pretty high price by a shop for repairing his board ($130), and that he would rather buy my board for $63 (plus $15 for installing the board, free installation if i get to keep the old board). His board still showed video, albeit with all kinds of fuzzy stuff over it. It still ran with the AMD display driver though.
I took the laptop apart and found something nasty. The NB did not have the thermal rubber on it anymore, there was just a blob of pretty dry white goop. He said he went to the warranty shop right after the warranty expired, and had it cleaned there. That was a couple years ago. Since then he's been taking it apart and cleaning it himself, but he said he never removed the heatsink or changed the paste. Alright, moving on...
He also had a Phenom II he wanted installed in place of the Athlon II it had. Okay no problem... As my luck would have it, my board worked great except one thing. The #!*$% board would give an error message saying that the fan wasn't working correctly on boot, and the fan would be maxed all the time.
I measured the fan RPM sensor circuit, and found it shorted. But it only had a pull-up resistor to 3.3v, and then it went straight into the KBC. F#!*. I put a lithium battery on the circuit and indeed, the KBC was the only thing getting hot.
Now, i would rather do a reballing rather than replace a KBC (especially for such a stupid issue), so i told him to leave the laptop here as it was getting late, and i'll fix his board instead.
I took the NB off his board and there was discoloration under the die, both on the chip and the board. Something told me that the chip is toast, but i reballed it anyway. I put it back on and it would crash when trying to load the AMD driver, only safe mode worked. I removed and re-installed it but same thing. I removed the undervolting resistor (yes, i'd undervolted it too), no change. I then took the board back out and measured the capacitors on the top of the chip, and some sections indeed measured shorted. This was confirmed later when i pulled the chip back out.
I believe the chip died during the desoldering process, so i could have caught it earlier on if i measured it. Oh well.
I had a spare RS880M so i reballed that one, lifted the original one from the board (again) and carefully cleaned the pads (again). I had some more solder mask scraping off but nothing that would make it short out. Soldered this chip on the board, it measured ok. Tried to power it on, nothing. No fan and just the wireless light on the keyboard lit up.
I thought that some flux had somehow made it in the CPU socket from my dirty hands handling the CPU and i was right. After brushing some IPA in the CPU socket, the fan turned on, but still no display. I plugged in my POST card and it seemed to be doing something, so i tried the VGA output. It worked. Hmm.
Then i thought i'd gave the display connector a good cleaning too, and guess what... We can haz video on LCD. AMD display driver now installed fine, and everything worked great. Hooray!
And undervolting it works as well. Another thing that needed some brushing was the touchpad ribbon, but oddly enough, the problem was at the touchpad side, not at the board side... I cleaned the ribbon well and flipped it around and now the touchpad works great too.
It's doing RTHDRIBL and Prime95 Blend test right now. I'll leave that running until i wake up.
IMO this thing doesn't deserve a Phenom, but hey, if that's what the guy wants... It's got an SSD in it too, and for what it is, it's not too shabby indeed, but i still wouldn't have put a quad-core in it. I get to keep the old Athlon II too and the price for the chip replacement will be quite a bit higher than $63 (but lower than $100+ he was quoted elsewhere), so i'm not complaining. But this was a LONG night.
Morale: Just because thermal pad/rubber is crap, it doesn't mean it'll work better WITHOUT it...
I have of course replaced the thermal rubber for the NB and used high quality paste on the CPU.Funny thing, there's another CQ56 waiting for me at work tomorrow. But that one only needs the dust bunnies kicked out and the touchpad fixed.
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