Aspire 5050 random lockups: think I know the problem

I bought my 5050 refurbished about two years ago with very little problems that I couldn't tackle. I apologize for all the text that I've typed below but I would like to detail my thoughts on why some of us experience random lockups [computer seems to freeze but might resume some time later like nothing happened]. My hopes are that others will read and possibly come up with more suggestions & chime in on this topic.

Cliffs:
1) lockup might be caused by rtc or surrounding circuitry
2) pressing lower right hand side of motherboard seems to fix temporarily.
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Sometimes the computer locks up and then it might continue after some time. It could happen as soon as you boot up (probably during POST) or after Windows is running.

By accident, I discovered that if I pressed on the lower-right hand of the laptop the computer resumes. This is not a simple press, but something like I'm almost trying to "bend" the corner off. I usually have to have the edge of the laptop off of the table in order for it to work. I'm not advising people to use this method but just telling my experience.

When the computer locks up, you can still move the mouse & the cursor updates, but you can't start new programs and programs that are already running seem to "freeze" (the desktop/Explorer included). You will see no hard drive activity (based on the LED). I usually know when the computer has 'resumed' correctly if I notice hard drive activity but we all know that's dependent on what tasks you are running.

A normal bootup on my computer at least is as follows:
1) Fan comes on
2) DVD/CD drive spins briefly
3) num-lock & caps-lock LEDs illuminate briefly
4) hard-disk LED comes on & hear hdd activity
5) BIOS POST stuff comes up on-screen
6) OS loads

A bootup that pauses from the get-go:
1) Fan comes on
2) DVD/CD drive spins briefly
3) num-lock & caps-lock LEDs illuminate briefly

So, as you can see #4, & #5 don't occur and the screen remains black. Using my 'pressing' method, #4 and #5 then occur and bootup continues.....until it gets to the OS.

Now, there's a reason I say 'OS' while in the previous text I've been saying 'Windows'. This is because the fact that I have a dual-boot system with Linux helped me to narrow down where the problem is.

Here's why: when I run Linux, I don't experience any freezing at all**, while if I boot up in Windows I have to manually 'unfreeze' every so often, sometimes having to 'press' constantly. Well you then might say it's an OS/software problem. But the thing is, freezing up happens even during or before the BIOS POST, so it can't be due to the OS only.

I think the problem is in the "real time clock (rtc)", and here's why:

Upon close inspection of booting up into Linux where I do not freeze up at all, I lied. There are two freeze-ups that occur during bootup & bootdown : when Linux retrieves the system clock on bootup, and saves the system clock on shutdown. The difference is that on Linux, it's not a freeze-up but a simple 5 or so second timeout and execution resumes as if nothing happened. The computer is not in a locked up state whatsoever during these 5 seconds. The exact error I receive is:

Code:

select() to /dev/rtc to wait for clock tick timed out

This means that the RTC didn't 'tick' so the i/o operation timed-out. I'm gonna guess and say that retrieving the hwclock on bootup and saving it on shutdown is really the only time linux tries to access the RTC, as I never experience any freezing-up at ALL.

I would go on a limb and say that Windows consistently tries to wait for an RTC tick as opposed to just accessing it on bootup & shutdown. If it doesn't, when it tries to wait for a tick, the timeout is either extremely long or simply a blocking operation. Therefore, for seamless execution, the RTC needs to keep ticking!

So in summary, I think the problem is with the RTC or the circuitry that connects it to the rest of the computer. Whether the RTC is in fact defective or there are some broken traces somewhere a physical adjustment temporarily connects that trace could be the problem.

Having the CMOS battery installed or uninstalled made no difference (just my CMOS values are always reset to defaults on every bootup, and the BIOS correctly says there is a problem in the CMOS storage or RTC).

I've also tried the usuals: no RAM, one DIMM at a time, no battery but off the AC adapter, hard drive disconnected, dvd/cd disconnected. Each variable still exhibited the lock-up which was fixed with a 'press'.

I have found the following threads which seem to relate to the problem I experience:

Aspire 5050 Booting trouble

Acer Aspire 5050- No Post

Acer 5050 - Locking Up

 

Bump for anyone with suggestions, comments, criticism, other things I should try, etc.