search for schematic of motherboard AsRock 4-core-dual sata2 fsb1066

[pelule]

Does anyhoe have the schematic of the AsRock Quad-core Dual sata2 fsb1066 motherboard?
  See details: https://www.asrock.com/mb/via/4coredual-sata2/
Or any tip how to to find the error?

My PC was running perfekt for many years (most the time powered on, seldom shut down).
Now we have an unusual hot season of more than 75 days of high temp so far. So I shutdown the system yesterday to reduce temp in my lab. Today morning it didn't start-up again.
If I press the power button the Pwr-LED lights on, but does not start up.
If I press the power button for longer time, the Pwr-LED goes off (as it should).
If I bridge the supply PowerOn the board gets power (fan & drives power on), but the CPU does not start.
Voltages are ok (in tolerance).
So I started to removed the external cables (LAN, USB, Audio) to remove the board, when it suddenly started. Unfortnuately I shut it down again to verify operation. It did not start-up again.
So I assume a on-board power-on circuits issue - potentially caused by:
1) weak(loose cable connection (tested, none found)
2) broken wire on the PCB (tested by knocking on the board at different locations, none found)
3) a bad capacitor (none suspicios found on a visible check)
4) bad power-on switch FET/Transistor (I cooled the semis around the power supply connector with cooling spray, none found)
So next planned step is to have a deeper into the power-on circuitry, thus I need the schemetic.
Any tipps or suggestions are alos highly welcome.
Thanks in advance.
/PeLuLe

[Rasz]

- you wont find diagrams for desktop boards
- 11 year old pentium4/core2 with 2GB ram limit is high time for upgrade. Replacement is free-$5.
- asrock are known for dying while turned off ) They arent exactly quality products, seems like thats where Asus send all of its under performing employees during the spinoff, you could say they werent sending their best. Things like bios corrupting on its own, or badly designed standby circuit frying from latchup/bad poweron voltage sequencing (whole series of 1150 boards died this way).

If you really need such old and useless computer find nearest recycling center and grab one from there, or check local classifieds (https://www.quora.com/What-are-the-best-websites-in-Germany-for-classified-ads) for similar computers people want to throw away.
If you want to learn about fixing pc motherboards ... find a broken laptop, because there are schematics available
If you have an emotional connection with this turd and really want to fix it start by finding all voltage regulators on the board and measuring outputs(while on/off). Check visually all the electrolytic caps, I wont tell you about ESR meter because its 2-5x the value of replacement board . Standby regulator is usually somewhere in the middle of the board near/between southbridge and ram slots, you have 2 candidates on your board. Check battery, reprogram/replace bios chip. PC post card is $3, so again more than replacement board should be .
Test with minimum configuration, that is bare motherboard with wither
-CPU
-pc speaker (will beep if cpu is running at all, we can go from there)
or
-CPU
-one ram stick
-ps2 keyboard (will blink twice signalling being initialized, that means almost whole bios ran without trouble, we can go from there)

[pelule]

Thanks for the feedback "Rasz".
Yes - you fully correct - a new system may be an option - I have a new 2017 systems for my video & office work.
This is may "old style data storage" system for SCSI, ZIP, 5.25 & 3.5 disks, IDE, SATA, USB, CD, Tape).
The performance is more than suffciant for that functions I need.
In addition I really hate to throw away & buy new, when there is a problem without at least trying to fix - you may call me stupid.

Meanwhile went further in the failure analysis.
"Power-On" signal on the ATX-Supply Connector is going "low" when pushing PowerOn button (and power LED went on), but "PowerOK" signal remains low.
Disconnected all loads (memory, add-on cards, drives, USB ... = mininimum system) and the systems powered on.
Step by step I re-plugged & powered-on (memory, video card, HDisk) - systems powered on each time.
Then let it powered-on to see if system runs stable - after ~1hour systems suddenly shut-down. Could be started again, but shut down again after a few seconds.
Seems the problem depends on temperature (actual I have 33°C in my lab).
Will investigate further...

[Rasz]

erm, just realized you went straight for the motherboard and I didnt even question it
those are classic dying power supply symptoms.

[pelule]

Hi Rasz
I agree, it looks like a power supply symptom - but it may also caused by a temperature switch off of the BIOS.
That I like to verify, when the room temp is down in the early morning.
I don't know the BIOS temp stettings, thus I like to check.

[joseph nicholas]

I have a question for anyone here, possible Rasz.

The bios screen on almost all computers in the hardware section gives alot of information about temperatures and voltages.  Plus alot of options on providing different voltage configurations for the cpu.  Is there a place on the internet with details about what the normal settings should be?

To take one value, the CR 2032 battery would this change as the battery ages?  The reason I ask is I've tried to replace this battery with a new one but they all seem to be defective with either no voltage at all or are they good but need to be recharged by the motherboard power supply?  My guess is that these lithium batteries are not rechargable but could they all be defective even when new?

Thanks in advance.

[Rasz]

I have a question for anyone here, possible Rasz.

The bios screen on almost all computers in the hardware section gives alot of information about temperatures and voltages.  Plus alot of options on providing different voltage configurations for the cpu.  Is there a place on the internet with details about what the normal settings should be?

To take one value, the CR 2032 battery would this change as the battery ages?  The reason I ask is I've tried to replace this battery with a new one but they all seem to be defective with either no voltage at all or are they good but need to be recharged by the motherboard power supply?  My guess is that these lithium batteries are not rechargable but could they all be defective even when new?

Thanks in advance.

3v lithium CR2032 batteries are non-rechargeable, Im not familiar with any motherboards showing cmos battery voltage level

[SaabFAN]

Just measure the 12V Rail with a Scope in AC-Mode and 20MHz Bandwidth-Limit activated.
If you see more than 120 mVpp at 2ms Timebase, a new PSU should fix the problem.
If the ripple-voltage is less, the problem is most likely located on the mainboard itself.

[Rasz]

Just measure the 12V Rail with a Scope in AC-Mode and 20MHz Bandwidth-Limit activated.
If you see more than 120 mVpp at 2ms Timebase, a new PSU should fix the problem.
If the ripple-voltage is less, the problem is most likely located on the mainboard itself.

personally I find it faster/easier to shotgun by swapping PSU for a known good

[xan]

It Will Be Harder to find schematics for this board... anyway... i suggest to start with PSU test, maybe using the same PSU on another board, if the PSU it's stable (and you don't have a scope) goes on! Remove all unnecessary hardware connected, install just one  DIMM module, If the sys is powered and can be turned on, so you can reflush BIOS, after force change BIOS Option to default settings, try to disable all features integrated like lan, pci, audio, etc .... as more as possible if you can (you need to locate the area where the problem is located) and then do a stress test (thera are more utility online), be carefull on temperatures on critical areas ,Power Mos, NothB, SouthB ....use a thermal couple or something like to inspect live temperatures (According on what you said before on 1st post).
A Question: What's the symptom on this board ?
For now you need only to take your time and make some extra test before remove some components! So Let's Do This! Good Luck 

[pelule]

Problem found & solved.
The cause:
The CPU cooler/fan had dirt and/or bad connection to the CPU - this caused the CPU to warm over the temp-limit & caused a safety shut down.
This early morning room temp was below 20°C and system started, runs ~20 minutes and suddenly shut down.
1st: used another PSU from my ok running office PC - same behaviour --> seems not related to the PSU.
    reconnected the "old" PSU.
2nd: I jumped into the BIOS temp monitor.
    Board temp stable at ~33°C, but CPU temp increased slowly up to 72°C and system shut down.
    Reproduceable.
3rd: cleaned the CPU cooler/fan from dust - thus I had to remove it and remount it again.
    (room temp ~28°C) Board temp stable at ~34°C, CPU temp increased slowly and become stable ad ~56°C
    no system shut down anymore.
Now system runs stable since more than 8 hours without any issue.
/PeLuLe