wrote:
> On Jul 2, 12:32 am, Paul <nos...@needed.com> wrote:
>> gbrook...@gmail.com wrote:
>>> I've got an 8RDA+ system that was running fine early today. (It is not
>>> overclocked, but I'm thinking overclockers may have some insights too,
>>> hence the cross post.)
>>> It was left on while people left the room. When they came back a few
>>> hours later it was dead. Now it won't even POST.
>>> History: ~3 weeks ago it started giving a message at boot time saying
>>> the CPU had changed. (It hadn't)
>>> I swapped in a new CMOS Battery and after a lot of other Windows
>>> related issues had the machine running fine again, except that it
>>> would complain that the 80 conductor 2nd-ary IDE Cable was not
>>> connected. (it was)
>>> After a while longer, it failed to boot because it didn't detect the
>>> floppy (which was still connected). I went into the BIOS and told it
>>> to ignore that error. It booted fine and continued working.
>>> Now it's dead. A few times I was able to get the power and fans to
>>> come on but the system would not even get to the BIOS screen. I
>>> checked the PS with a volt meter and got proper voltages on the
>>> peripheral connectors (+5v, +12v) The LED error codes would stop at a
>>> different value each time it froze: 00, FF, C1, CF, 0d. It was very
>>> random. I would sometime get long beeps. Then I started getting hi-
>>> lo-hi-lo alternating beeps.
>>> I disconnected ALL the IDE cables and their power supplies and even
>>> the MoBo from the PS. Then I reconnected them all and now I don't
>>> even get power or fans. I can see the NIC lights (yellow and green)
>>> come on, and I can see the LED briefly flash FF (<0.5sec).
>>> I'm starting to think the BIOS Chip went south. Any other
>>> suggestions?
>>> This machine has been a trooper and I'd hate to see it go.
>>> I'd appreciate any pointers.
>>> Thanks.
>>> Glen
>> The hi-lo-hi-lo police siren, suggests you should have a look at
>> the capacitors near the CPU socket.
>>
>> http://www.nforcershq.com/forum/1-vt65416.html?start=0
>>
>> There is a closeup here, of some bad capacitors. The reason the
>> ones around the CPU tend to go, is because they are under the
>> most stress (high ripple current). Also, look on the PCB, as there
>> could be a brown stain, where a liquid leaked and dried up.
>>
>> http://www.badcaps.net/images/caps/kt7/image004.png
>>
>> If you don't stop using a motherboard, when the capacitors start
>> to go, there can be collateral damage. The MOSFETs or the
>> toroidal coils near the caps, can fail as a result of the
>> overload caused by failed caps.
>>
>> People have managed to fix things like this, but at some
>> point, the amount spent on parts or tools, outweighs
>> any possible saving. For example, one guy used to charge
>> $50 to re-cap a board, but for that price, you might find
>> a whole replacement board on Ebay. Some enjoy stuff like
>> this, and for them the money is not an issue.
>>
>> Paul- Hide quoted text -
>>
>> - Show quoted text -
>
> Thanks for the suggestions. I checked all the electrolytics on the
> board and they all look pristine. No evidence of swelling or
> leakage.
>
> Other ideas?
>
> Glen
>
The thing is, your symptoms suggested I/O related problems,
and the problems don't necessarily all share the same
voltage. There are regulators on the motherboard, some
to power the CPU, some for the chipset, one for AGP slot,
and so on, and something like that could be having a problem.
Not all the important voltages on the board, show up in the
hardware monitor BIOS screen.
About all you can do, is start unplugging stuff, and see if
you can get any error beeps out of it. That would tell you
BIOS code is running, the CPU is working, and the chipset
has power. For example, with no video card or RAM present,
you should get a beep code. And the beep code should continue
to repeat.
If the checksum on the main BIOS code was bad, then the
BIOS may attempt to access the floppy, looking for a way
to repair the BIOS. The code to do that, is in the boot
block in the BIOS.
And since you have a POST code display, that is an even easier
way to check for progress. If the display stays at FF, then
there isn't any processing going on.
If the display can only show the FF code for a short period,
I'd be asking what was powering the display. From experience,
you probably know whether that display has a blanking function,
and is capable of turning off the LEDs on the display, under
normal circumstances. Or whether the LEDs on the display,
would normally be running all the time.
Paul