Own Custom Build Computer With ECS Motherboard-No POST

[LENOVO-A880]

Re: Own Custom Build Computer With ECS Motherboard-No POST

Well, I do agree with you Agent24 ....polymod can come as a last resort. I should start to check the standard voltages on the motherboard with a multimeter but I've lot of hard time finding those rails like CPU core; Ram VDD; Northbridge VCC and Southbridge VCC or others which I'm not familiar with them yet. Honestly, I'm lacked of electronic components level skill, so I need your help finding those rails and signals to identify the problem precisely. It will always be great if you can really provide me with some clear pictures on those rails like you have said before..

...You need to check all these rails to be sure they exist and are the correct voltage. You need to check the power-on signals to SIO etc to see if they exist and are OK..

And please help me on how to trace those power-on signals on the the motherboard by referring the sequential part of the schematic (page30). I'm completely noob about this here.

[Agent24]

Re: Own Custom Build Computer With ECS Motherboard-No POST

Forget polymodding or anything like that for now.
You've got a new PSU, and the board still doesn't work, so start troubleshooting the board.

Troubleshoot the motherboard and repair until it's in a working state, and then maybe do some polymod. Don't start modding things when they don't even work to begin with! If you screw up the mod you won't know if the reason it doesn't work is because of the original fault or the mod. It just confuses things.


So.... First of all, I would check all the system voltages on the board and power-on signals.

See page 29 of the schematic for the power distribution chart and page 30 for the power sequence. You need to check all these rails to be sure they exist and are the correct voltage. You need to check the power-on signals to SIO etc to see if they exist and are OK.

Do you need help finding where to measure them?

[LENOVO-A880]

Re: Own Custom Build Computer With ECS Motherboard-No POST

....As it currently stands, your power supply needs, at the very minimum, an input filter choke (also known as EMI/RFI supression choke/coil), bigger input and output capacitors

.... I have replaced my unit PSU with a decent one which is the FSP HEXA+ 550W recently but the ECS motherboard still unable to boot up. Well, since I have narrowed the problem down to a PSU or motherboard, likely 95% chances of power related problem which caused motherboard being unstable. How about a PSU that keeps its output well within the required voltages, but has a huge amount of ripple and kill those polymer capacitors on the motherboard? And likely these capacitors here took up the ripple current from a poor quality PSU, causing them to heat up badly. Then how about a crappy PSU with non-functioning OVP. If that puts out high voltages, or high voltage spikes, there is nothing to shut it off, so the voltages could fluctuate fairly high too. Those sudden jumps between voltages could give voltage regulators problems too, which could give high output spikes to the RAM, CPU, chipset, GPU, etc. I've heard and seen horror stories of PSUs failing, and killing components. So my question here will a polymod on my ECS G31T-M7 motherboard especially on the PSU sides fix this problem here?

Thanks

*Update*

POLYMER CAPACITOR PLAGUE
A capacitor can fail open so that it's disturbing the flow of electricity in a circuit and then the circuit is no longer working at all. Polymer type capacitor can also failed shorted unfortunately or fail open without any visible signs. Polymer capacitor, don't have much of the problems of electrolytic capacitors. They don't leak or swell, due to absence of electrolyte which would cause gases inside. However it's possible one of them is shorted or damaged without showing any signs due to extreme heat (ex: MOSFETs near them shorted or broken and heating every others component around) but this would happen with any series of polymer type capacitors. It's also unlikely. More likely you have some shorted MOSFETs / cracked ceramic capacitors due to high voltages

[c_hegge]

Re: Own Custom Build Computer With ECS Motherboard-No POST

I think that there is a very good possibility that the PSU has just slow-cooked the motherboard. With only one cap per rail, I can almost guarantee that the ripple would have been way out of spec from day 1.

[Agent24]

Re: Own Custom Build Computer With ECS Motherboard-No POST

That is a cheap and horrible looking PSU and I would be suspicious of its capability. At this point I would try a known working\good PSU in the PC because:

The Asia'x capacitors are not known to be good, and in that PSU could well have dried out from age and heat causing high ripple levels which mean the board won't start and the +12v rail is low.

With an old, cheap and unknown condition PSU like that, the best thing to do is just swap with a known good one to start with.

[momaka]

Re: Own Custom Build Computer With ECS Motherboard-No POST

I didn't know that a PSU could destroy a mobo, and assumed that they would all have built in over-current protection as a basic feature. The PSU fan was a bit noisy before this and I disregarded it as being in danger of failing.

Yes, a PSU can indeed destroy a motherboard when it fails catastrophically. This usually happens with cheap power supplies, since they lack some protection circuits (or when the protection circuits are not implemented properly).

However, the worst are power supplies that seem to work "fine" (i.e. all voltages come up), but they have too much ripple on the output, causing the PC to crash or not boot reliably. And looking at the pictures you posted, this could very well be the problem here. Your PSU has undersized input caps, only a single output cap per rail and without PI coils... Basically, your PSU likely is outputting too much ripple, which could easily be causing the motherboard not to boot.

Those scorch marks on PSU metal case show some components catastrophically failed, but only the discolored on the PCB (PIC-D) will tell if something else might be overheated (PIC-C).

Could be dust too. I've seen similar "phenomena" in other electronics. Usually fine dust in combination with heat causes it. If this was due to components that failed in the PSU, it wouldn't have worked at all.

How can I check if my motherboard or the system wasn't sufficiently damaged before I replace a new PSU to test on it?

Aside from a few basic checks, you can't really. A good power supply is needed to test the computer. If you don't want to buy a new power supply, see if you can borrow one from a friend (and preferably a good one).

How can I check if the Processor and RAM can still be reused on the system as they can be easily toasted by PSU fault?

It is extremely rare for the RAM or the CPU to get toasted. The voltage regulation circuits on the motherboard provide fairly good isolation from the PSU.
That said, if the RAM is toasted and you try it on another computer, in almost all cases the PC just won't boot, but the motherboard won't be destroyed.
Trying a toasted CPU in a good motherboard is a little less safe (depending on how the manufacturers designed the motherboard), but again, in most cases the motherboard will survive the "bad" CPU. Probably will trip the PSU short-circuit protection if the CPU is badly shorted. However, if you are using a cheap power supply, as mentioned above, the PSU may not trip and blow up.

So all in all, it is good to have a reliable power supply on hand.

Do you recommend any advise to reapply the thermal compound on the Processor and SouthBridge chipset heatsink with better thermal paste?

Well, if you want to rule that out as a possibility of the PC not booting, then go ahead.

Normally, I don't reapply thermal compound when *testing* computers, unless the compound looks extremely dry or the CPU has an exposed-core (i.e. one without a heat spreader, such as AMD socket A/462, Pentium 3, or a mobile CPU).

You have socket 775 CPU, and it more than likely has a heat-spreader. So for testing, you don't necessarily need to reapply thermal compound - just leave the old one on there. But if you already have thermal compound on hand or can get it for cheap, then give it a try.

Normally what will be the watts of soldering iron that can be used to replace the capacitors on the PSU circuit board?

For most PSUs, 35-40W is about enough. But if you are new to soldering, around 50W might be a little better for you. However, if you are planning to recap motherboards, 60W may be better to have.

That said, I don't think a simple recap will help your PSU too much. If anything, it needs a few mods in there as well - and unless you can obtain the needed parts for cheap, it isn't really worth it. Of course, that also all depends on what kind of power supplies you have on your market in Malaysia. If you can get a new decent PSU for a good price, then that might be the best option. Otherwise, you may have to just get a bunch of junk power supplies and see if you can make a "decent" one by taking parts from the others - but that's something I would rather not have you do if you are inexperienced with electronics component level repair.

As it currently stands, your power supply needs, at the very minimum, an input filter choke (also known as EMI/RFI supression choke/coil), bigger input and output capacitors (for output capacitors, you may want to up the capacity to at least 3300 uF per rail, since your PSU does not have PI coils), and clean that likely-conductive brown glue.

*UPDATE: Here I have found some information about the brown crusty stuff on the PSU circuit board. This stuff is probably glue (like RTV), used to secure the large components like transistors heatsink and capacitor with high capacity from snapping their tiny little legs during soldering and assembly. As it ages, it can become conductive enough to short components and kill them.

Good job on your research . That brown stuff in your PSU is exactly like you found - cheap glue that turns conductive over time. Clean it off as much as you can - or at least from all metal parts and component leads. That could very well be why the board is starting to darken around the 5VSB section.

[LENOVO-A880]

Re: Own Custom Build Computer With ECS Motherboard-No POST

Hi Agent24,

Thanks for your analyzed on the 12V line which indicated the PSU will actually fail without any signs. I didn't know that a PSU could destroy a mobo, and assumed that they would all have built in over-current protection as a basic feature. The PSU fan was a bit noisy before this and I disregarded it as being in danger of failing. First couple photos are some brown crusty stuff on the bottom of the 2 primary-side capacitors on the board. Is that electrolyte or just adhesive to hold the capacitors in place before soldering (PIC-A)? The leg of one of the heatsink for those transistors show signs of this brown crud as well (PIC-B). If it was a leaking capacitor, I'll replace them with new one....

Those scorch marks on PSU metal case show some components catastrophically failed, but only the discolored on the PCB (PIC-D) will tell if something else might be overheated (PIC-C).

Questions

1. How can I check if my motherboard or the system wasn't sufficiently damaged before I replace a new PSU to test on it?
2. How can I check if the Processor and RAM can still be reused on the system as they can be easily toasted by PSU fault?
3. Do you recommend any advise to reapply the thermal compound on the Processor and SouthBridge chipset heatsink with better thermal paste?
4. Normally what will be the watts of soldering iron that can be used to replace the capacitors on the PSU circuit board?

*UPDATE: Here I have found some information about the brown crusty stuff on the PSU circuit board. This stuff is probably glue (like RTV), used to secure the large components like transistors heatsink and capacitor with high capacity from snapping their tiny little legs during soldering and assembly. As it ages, it can become conductive enough to short components and kill them. Notice there is some corrosion on the leg of the heatsink (PIC-B). The dried out glue can absorb moisture from the air & begin to corrode components like capacitors; heatsink. Here is a forum post that talks about it: (http://www.electronicspoint.com/awfu...ds-t61364.html)

[Agent24]

Re: Own Custom Build Computer With ECS Motherboard-No POST

Your voltages are all within tolerances but the 12v line seems a little low. It could indicate the PSU has issues.

I would really advise you try another, known working PSU before you delve into trying to troubleshoot a motherboard problem that may not exist.

At the very least, have you looked inside the PSU to check there are no bad capacitors? If there are any, the PSU is suspect and you must try another one.

[RJARRRPCGP]

Re: Own Custom Build Computer With ECS Motherboard-No POST

[*]Could a bad Northbridge chipset be the culprit here?

More likely a bad socket pin on socket 775 than a bad northbridge.

Did you inspect the socket?

[LENOVO-A880]

Re: Own Custom Build Computer With ECS Motherboard-No POST

Hi Agent24,

I put back those Teapo 100uF 16V and Nichicon 1000uF 6.3V to the ECS motherboard. I tested it with a (12V based) computer basically with CPU, heatsink, and the PSU which I had previously tested it without loads on it. Those 5V and 3V rails fluctuate a bit but 12V is almost stable. Are these results here acceptable?

20-pins connector:

+3.3V ORNG WIRE(T1)
PIN 1, 2, 11 - 3.23V

+5V RED WIRES(T2)
PIN 4, 6, 19, 20 - 5.24V

+12V YELLOW WIRE(T3)
PIN 10 - 11.89V

+5VSB PURPLE WIRE(T4)
PIN 9 - 5.10V

-12V BLUE WIRE(T5)
PIN 12 -(-11.91V)

POWER_OK GREY WIRE(T8)
PIN 8 - 5.23V

4-pins connector on 12V:

PIN 1 / PIN 3 - 11.84V(T9)

PS_ON logic signal

GREEN WIRE (PSU SWITCH ON)
PIN 14 - 0.05V(T6)

GREEN WIRE (PSU SWITCH OFF)
PIN 14 - 3.92V(T7)

..however those symptoms from my first post are still remaining unchanged till now. BTW others like the CPU and Northbridge chip, both were running quite warm when powered up. Now it appears the board "flex" under the CPU socket when the heatsink is on. Anyway likely if the PSU is good I will have a few questions to begin here...

Question:

1. Would it be likely a CPU unable to communicate with rest of board due to broken traces, bad chipset, or power issues?
2. Could this be a possible bad BIOS chip, or bad communication with BIOS chip to the point where no meaningful code is executing on power on?
3. Could a bad Northbridge chipset be the culprit here? Can a burned component like voltage regulator or PWM chip will likely be the one?
4. Would like to know how to test a bad motherboard and also replacing components like FET if it turns up to be the problem..

[Agent24]

Re: Own Custom Build Computer With ECS Motherboard-No POST

It sounds like your PSU is OK - with no load anyway. All the voltages look fine.
To confirm you could try reconnecting the PSU to the computer, powering up and reading all voltages again. If the PSU is the problem, you may notice some significant difference in voltage.

If you have another PSU, or another PC to try this PSU in, that will also help to narrow it down between PSU or motherboard...

[LENOVO-A880]

Re: Own Custom Build Computer With ECS Motherboard-No POST

Something else to try is to "load" the supply with 12v and 6v car bulbs to see
if the 12v and 6v voltages hold up

seriously I have never tried that before but do you have any photos or perhaps some links from another sites to safely perform this type of PSU test that you mentioned to test with a 12V and 6V bulbs. Another thing is will this test show any kind of signs that a PSU is bad like current will be drawn to those car bulbs, ending up to be dimmer than normal? It sounds sensible to me if they do. Anyway thanks for giving me such important information regarding any other possible solutions to my problem here.

[selldoor]

Re: Own Custom Build Computer With ECS Motherboard-No POST

Something else to try is to "load" the supply with 12v and 6v car bulbs to see
if the 12v and 6v voltages hold up

[LENOVO-A880]

Re: Own Custom Build Computer With ECS Motherboard-No POST

........All ATX PSU have a PWR_GOOD signal which outputs a high level (should be between 3v and 5v) when the PSU is running and its self-monitoring circuitry determines the voltages are OK. This signal is output on the GREY wire.

You did not mention in your previous posts if you had changed the PSU or not.......then at least check the PWR_GOOD signal is present.

.....sorry here for not giving the PSU a full check on those serious PWR_GOOD logic voltage and also for all the rest of the rails. At this point I made a recheck again using my DMM. Hopefully this time I can really isolate any problems related to the PSU before I further up the test on the motherboard for suspected logic short. Again here I would like to say thanks a lot Agent24 for replying my previous post and I feel a bit upset for all of these retarded posts and still no solution has been found. I will keep trying to repair this ECS motherboard but before that this is what I have tested on the PSU without attaching the 24-pin connector to the motherboard:

20-pins connector:

+5V RED WIRES(PIC-A)
PIN 4, 6, 19, 20 - 5.23V

+5VSB PURPLE WIRE(PIC-B)
PIN 9 - 5.13V

+12V YELLOW WIRE(PIC-C)
PIN 10 - 12.05V

+3.3V ORNG WIRE(PIC-D)
PIN 1, 2, 11 - 3.3V

POWER_OK GREY WIRE(PIC-E)
PIN 8 - 5.23V

Additional 4-pins connector:

+12V YELLOW WIRE(PIC-F)
PIN 10 ABOVE - 12.05V

+3.3V ORNG WIRE(PIC-F)
PIN 10 ABOVE - 3.3V

+5V RED WIRE(PIC-F)
PIN 20 ABOVE - 5.23V

GND BLACK WIRES(ALL)
PIN 3, 5, 7, 15, 16, 17 - COM

BTW I think the voltages which I checked here are still within +5% tolerances if not mistaken. If all of these voltages are still within the normal working PSU specifications, should I change to another PSU for further testing the motherboard or what kind of test should be performed next? Any suggestions please?

[Agent24]

Re: Own Custom Build Computer With ECS Motherboard-No POST

I couldn't check whether the PSU will be able to deliver 5V Power_OK signal at main ATX power connector if some of the capacitors on the motherboard are not intact yet. I have removed one of the Nichicon 1000uF and Teapo 100uF from the motherboard. I have heard that countless cases where faulty capacitors have caused inductors to overheat, and other bad stuffs to arise. Those 2 capacitors can be found from the attachment below this post here...

I might have been confusing you. All ATX PSU have a PWR_GOOD signal which outputs a high level (should be between 3v and 5v) when the PSU is running and its self-monitoring circuitry determines the voltages are OK. This signal is output on the GREY wire.

This signal will be generated by the PSU regardless of the state of any attached hardware, or even if there is no hardware attached and you are turning the PSU on by pulling PS_ON (Green wire) low.

Sometimes the PSU can fail in such a way that all the output voltages are OK, but the PWR_GOOD signal is not generated. If the PWR_GOOD signal is not generated, the motherboard will assume the PSU has wrong voltages and the motherboard will not come out of reset.

You did not mention in your previous posts if you had changed the PSU or not. You did say the voltages were OK but you did not mention the PWR_GOOD signal. If you cannot try a different PSU, then at least check the PWR_GOOD signal is present.

[LENOVO-A880]

Re: Own Custom Build Computer With ECS Motherboard-No POST

I will try to help but can you upload the whole schematic file or give the link of where you found it? It's hard to read the file you have uploaded.

Thanks for the reply. I'm really sorry about the hard to read schematic file which I got it from an unknown website. Tried power up with only a PSU but without the CPU & its 12V. Still couldn't get any POST or beeps.

Did you check Power_OK signal from the PSU at the main ATX power connector?

I couldn't check whether the PSU will be able to deliver 5V Power_OK signal at main ATX power connector if some of the capacitors on the motherboard are not intact yet. I have removed one of the Nichicon 1000uF and Teapo 100uF from the motherboard. I have heard that countless cases where faulty capacitors have caused inductors to overheat, and other bad stuffs to arise. Those 2 capacitors can be found from the attachment below this post here...

Attached here is the link to the SIO chip specification. I'm still learning through page 9, 10, 11 & 24 but not totally understand. Besides that I will like to ask for another help about the Nichicon PW series capacitor which C_hegge stated from this post...

About the Teapo....YOu can replace it either with another GP cap or bette,r an entry level low ESR cap (Nichicon PW or HE, Panny FC, or NCC LXZ)

Will this Nichicon PW Part No: UPW1C101MED1TD can replace the Teapo 16V 100uF from the motherboard. The Nichicon PW series link can be found here (http://my.element14.com/nichicon/upw...tor/dp/2370577). BTW thanks again to you C_hegge for the valuable information about this capacitor replacement which you have spent your time to provide them to me.

Thank you.

[Agent24]

Re: Own Custom Build Computer With ECS Motherboard-No POST

Thanks again for your reply Agent24. However I have managed to download the ECS G31T-M7 REV 1.0 schematic but don't really understand about the control signals from the SIO chip which you have mentioned from the post above. Do you have any suggestions on how to trace or locate the control signal pins? I have attached here the SIO pinouts which will be helpful to check for PWR OK voltages and its signal from the power supply.

I will try to help but can you upload the whole schematic file or give the link of where you found it? It's hard to read the file you have uploaded.

Did you check Power_OK signal from the PSU at the main ATX power connector?

[c_hegge]

Re: Own Custom Build Computer With ECS Motherboard-No POST

About the Teapo, if the datasheet doesn't state the ESR, then that means it is a General purpose cap (NOT a low ESR cap). YOu can replace it either with another GP cap or bette,r an entry level low ESR cap (Nichicon PW or HE, Panny FC, or NCC LXZ)

[LENOVO-A880]

Re: Own Custom Build Computer With ECS Motherboard-No POST

Agree. With my recent fun with motherboard troubleshooting I would say start with voltages and power good signals.

Is the PSU sending the power good signal, for a start? If not, it will make the board stay in reset state and do nothing.

Get a schematic of the board if you can. If you can't, get a pinout of the SuperIO chip and find the control signals...

Thanks again for your reply Agent24. However I have managed to download the ECS G31T-M7 REV 1.0 schematic but don't really understand about the control signals from the SIO chip which you have mentioned from the post above. Do you have any suggestions on how to trace or locate the control signal pins? I have attached here the SIO pinouts which will be helpful to check for PWR OK voltages and its signal from the power supply.

[LENOVO-A880]

Re: Own Custom Build Computer With ECS Motherboard-No POST

Which voltages did you check? And what were they?
You need to check CPU V_core, CPU Vtt, RAM Vdd (should be 1.8V), Ram Vtt (usually about 1/2 of RAM Vdd), Northbridge Vcc, and Southbridge Vcc.
Let me know if you need help locating those.

Thanks first of all and yes I do think I will need some references on the working voltages for those CPU V _core, CPU Vtt, RAM Vdd, RAM Vtt, Northbrige VCC and also Southbridge VCC . I was having a lot of troubles locating and spent quite a while checking those MOSFETS (VRM IN and OUT) by the way I think I found the problem. Unfortunately there was a shorted FET on the ECS motherboard from the reading on my multimeter. At the moment, I need to replace the shorted voltage regulator then only I will be proceeding to further testing the motherboard using schematic if possible. I think that is what I have managed to work on to save this motherboard.
Field Effect Transistor

Does the Num Lock light work if you repeatedly push the Num Lock key? And does it lock into an either OFF or ON state after a while? If yes, that usually indicates a hard crash (i.e. BIOS didn't finish loading or never even started)

I don't think the Num Lock is in anyway working as it should be but the mouse is OK. The Num Lock button I think is no stucked or defective. Both the mouse and keyboard are PS2 ports.

As for the Teapo - most appear to be on the 5VSB or USB V lines from what I can tell, or other non-important rails. The only troublesome Teapos are the one in the lower right corner of the board in your picture (by the RAM slots), and the one by the "SYS_FAN" connector, which .

Do you know if there are any replacement capacitors for this Teapo 16V 100 uF capacitor? I just have hard time finding it all around the sites like RS-Components, Element14 and Mouser but still fail to get one which is suitable. The ESR for this Teapo capacitor is almost no where to be found. Would you please help me!!!