H57H-AM2 Motherboard with CPU voltage problem

[dicky96]

Hi guys
I have this H57H-AM2 V2.0 motherboard here, I'm trying to fix it to improve my own knowledge.

It has an i5-650 CPU. The board is basically dead - the fan spins but it doesn't beep or POST (00 on post diagnostic card), testing just with a bare board+CPU

What I have found is that the CPU voltage seems unusually low (unless I just need more experience to determine that is true) Also the CPU does not get warm with the heatsink fitted and without the heatsink it just heats up very slowly

The attached image shows what voltages I am getting. The first figure is with no CPU fitted and the second is with the i5 CPU

I don't have another LGA1156 CPU or motherboard here at the moment to prove if the CPU is any good

I did wonder if this is a BIOS problem as I have seen boards powering up but acting 'dead' with a corrupted BIOS, but I don't know how to program the BIOS as it appears to be embedded in the Super IO chip IT8721F.

I assume I can use an exterrnal SPI programmer but how do I connect that? I found some tutorials for that on youtube but from what that taught me i need to know where to connect CS, MOSI, MISO and SCLK.

There are 4 header pins right near the IT8721F but two of those pins connect to ground so that can't be what I need, and I couldn't find a datasheet nor any info in the motherboard manual.

[piernov]

Re: H57H-AM2 Motherboard with CPU voltage problem

The ITE IT8721F doesn't have a flash memory for the BIOS, it is an SPI ROM located somewhere else on the board. (see attached picture)

From your picture, I get that there are 3 phases for CPU VCore ( 1.3xxV/0.8xxV ), 1 phase for VCCSA ( 1.147V/1.117V), and one phase for VCCAXG (0.0V/1.001V).

Typically CPU VCore will start at a higher voltage then drop a bit after BIOS is running, and usually VCCAXG won't come up if BIOS is not running. So basically my guess is that the board is actually getting pretty far in the POST process.
Which in itself is kinda weird if you have no RAM... I don't exactly remember the behaviour on 1st gen though…
To check the CPU VCore behaviour you can probe the CPU VCore then turn on the board, it should start at 1.1V then drop to 0.9V.


PS: dunno if this subforum is the best place to post this stuff, I don't check the posts here very often, I take a regular look at the Laptops subforum and the Motherboards with Bad Capacitors section instead usually.

[dicky96]

Re: H57H-AM2 Motherboard with CPU voltage problem

Thanks piernov. you obviously have the knowledge I am trying to gain. My mistake for not being able to find the ROM chip.

I'll work through your suggestions of the voltage boot up sequence and try to understand what is happening.

I'm not sure where to post this sort of discussion as there is not a section here for desktop motherboards, gaming motherboards and GPU which is where I want to concentrate my effort

I have asked if that section could be added

best regards
Rich

[ChaosLegionnaire]

Re: H57H-AM2 Motherboard with CPU voltage problem

just post it in the relevant subforum in the motherboards with bad caps section even if the problem isnt bad caps related, just post it there anyway because some people post their boards there even if the problem isnt bad caps. this looks like a gigabyte board from the model number but from the pics it looks like a board made for the oem computer market so an admin should move this to either the ecs epox and gigabyte subforum or major manufacturers board subforum.

[stj]

Re: H57H-AM2 Motherboard with CPU voltage problem

nice rust on the cpu clamp.
you may want to look with a magnifying glass at the socket pins - if any arent straight - see if they are loose.

i have seen several boards with bad sockets because they where stored or moved without a cpu and something hit the pins.

[dicky96]

Re: H57H-AM2 Motherboard with CPU voltage problem

@sti yes I had wondered about the rust on the CPU clamp
I don't have the kit to remove/change CPU sockets - Yet.... but I can look under the clamp as you suggest. The pins are fine, on my microscope

@ChaosLegionaire
OK I'll use those sections in future - I took the Forum headings too literally

OK there seems to be something wrong with the BIOS chip. Its a Winbond 25Q16BV. I selected W25Q16BV in the TL866

When i tried using the clip to read the Eprom on the motherboard it just said 'Current Protection' though I don't see any shorts form the Eprom pins to ground on my multimeter.

Anyway I unsoldered it and found I could get my clip to hold it tightly even though not mounted to a PCB (see pic)

When I try to read it, everytime i get a different ID code, example 0x
DC 00 80
EF 40 0E
DC 00 A0
DC 00 80 (again)
DE 00 28


When I read it with Check ID deselected, it reads and produces a 2Mb BIN file but it is mostly FF with small blocks of data, and if I read it again I get slightly different BIN files

I've attached two of them. So if I am not making some newbie error then there appears to be a problem with the BIOS chip

Rich

[piernov]

Re: H57H-AM2 Motherboard with CPU voltage problem

When on the board, the programmer cannot supply enough current because it'll try to power the whole 3V power rail, which is also connected to southbridge, Ethernet controller and a lot of stuff like this.

When off the board, it just looks like it's not making good contact. Clean the pin and maybe use some sand paper or something like that.

[dicky96]

Re: H57H-AM2 Motherboard with CPU voltage problem

When on the board, the programmer cannot supply enough current because it'll try to power the whole 3V power rail, which is also connected to southbridge, Ethernet controller and a lot of stuff like this.

When off the board, it just looks like it's not making good contact. Clean the pin and maybe use some sand paper or something like that.

OK thanks
I'll solder it to the SOP8 header board that came with the TL866A. Then I can be sure

[dicky96]

Re: H57H-AM2 Motherboard with CPU voltage problem

OK, so I tried cleaning the pins on the eprom with an emery board (well that's what the missus calls the things she files her nails with, anyway) but I still couldn't get a good contact on the clip

So I soldered it to the SOP8 pin header instead. I could then read the eprom properly, which Check ID ticked. I could also use the clip lead to connect to the chip once it was soldered to the pin header PCB and read the BIOS properly.

I made a backup of the eprom BIN file and compared it with a downloaded BIOS which I think is the right one for this motherboard as it appears to be an OEM item used in various computers http://www.mxdtr.com/h57h-am2-drivers-bios-update/

They were very similar in structure but different.

As I am not sure that is the correct BIOS file I then unsoldered the BIOS and was going to put it back on the motherboard, but had a change of heart and soldered it back to the SOP8 header.

I read it again and compared with my original backup some areas had changed! I took a third backup and that was identical to backup number 2.

I wrote the original backup and it verified OK. I then decided to write the downloaded BIOS file anyway, and that also programmed and verified OK.

So I'm a bit confused how the contents changed apparently by unsoldering and resoldering.... maybe this chip does have a problem?

I then put the reprogrammed BIOS back in the motherboard and it was behaving exactly the same as before. so I decided to have a look at the CPU voltages on startup as piernov suggests

I couldn't see the Vcore start high then drop low on my Fluke multimeter, it just went from 0 to the low 0.8xxx voltage. Similar with VCCAXG it just goes directly to 1.1V on power up.

Thinking maybe the Fluke wasn't fast enough I decided to look on my scope instead.

If there is any delay from power on to VCCAXG going to 1V then I can't see it. Same with Vcore it just seems to go directly to 0.8xxxV on power on.

Then I had this really bright idea

I thought, seeing as the BIOS is an SPI chip, it might be a good idea to fit the SOP8 clip to the BIOS chip on the motherboard and connect it to my Saleae16 logic analyzer - cos that can read and analyze SPI data

I'm thinking if I capture the data coming from the BIOS and save it as a file then maybe I can then put that into a disassembler and see what the CPU is actually executing.

But... I didn't get that far. I decided to have a quick look around the BIOS pins on my scope first - and as far as I can see the pins are all static at 3.3V apart from ground at 0V. I don't see any CLK, DO, DI or CS pulses even at power on. I would have thought i should see something.

This is turning into an interesting diagnostic problem. I hope others here are enjoying it as much as me.

So What next?
Get a known good LGA1156 CPU (I can buy a used i3 gen 1 for less than 5 euros)?
Have a look at the Super IO pins (though I didn't find a datasheet yet)?

Rich

[stj]

Re: H57H-AM2 Motherboard with CPU voltage problem

check the clock generator/PLL chip.
make sure it's crystal is running and it has outputs.

[dicky96]

Re: H57H-AM2 Motherboard with CPU voltage problem

check the clock generator/PLL chip.
make sure it's crystal is running and it has outputs.

That sounds like a good idea. Also is there somwhere I can probe the CPU reset pin?

[stj]

Re: H57H-AM2 Motherboard with CPU voltage problem

maybe,
does the board have pads on the bottom that mirror the bga pads for the chipset?

[dicky96]

Re: H57H-AM2 Motherboard with CPU voltage problem

@stj - no I don't think so. I've attached some pics of the rear of the board

I had a look around to see if I could identify the clock generator chip. I think it may be this one RS4180BL but can't find a datasheet to confirm that. I didn't spot any other likely candidates, in fact I eliminated quite a few chips and there are several crystals in the area around RS4180BL

One of the crystals X1 is 25MHz and has some nasty corrosion around it. However it does appear to be oscillating but with a low level signal. See pics. The RTC Crystal has the same sort of amplitude. I'll have a look in my spares to see if I have another 25MHz crystal just to be sure it is good, but I think it probably is.

There is another crystal KX1 very close to the RS4180BL and the markings are not distinct and that is oscillating at 14.29MHz at a much greater amplitude.

I had a look around the capacitors and resistors surrounding the RS4180BL but could not see any other oscillations (multiplied/divided frequencies for example)

Also there was some more corrosion around this chip. I've resoldered some of the iffy looking joints on passives and then used flux and reflowed the RS4180BL. It looks cleaner now but it didn't make any difference.

The RS4180BL is cold. Also the Super IO doesn't seem to get warm either. I had a bit of a poke around the passives near to the Super IO and I could find some 0V levels, some 3.3V levels and some floating voltages around 1V but no 'activity/signals' as such.

The DDR3 Voltage is present 1.5V.

I think I'll have a look at the pin out for DDR3 slots and look if there is anything worth checking there such as clock signals

The lack of datasheets for RS4180BL and the Super IO IT8721F isn't helping matters

Rich

[stj]

Re: H57H-AM2 Motherboard with CPU voltage problem

did you check the battery voltage?
and cleaning the board may help.

[dicky96]

Re: H57H-AM2 Motherboard with CPU voltage problem

did you check the battery voltage?
and cleaning the board may help.

Yeah I replaced the CMOS battery with a new one. And it is not discharging over the last few days, it's fine

What would you suggest for cleaning the motherboard? We get this all pervasive greyish brown dust here which gets into everything, but on the plus side it almost never rains here :-)

I use Isopropyl Alcohol and a dry paintbrush to clean small areas of boards, and to clean flux after rework.

I do have an ultrasonic cleaner on my list of equipment to buy.

I looked up the pinout for the DDR3 slot to see where the Clock signal should be. It looks like I have no system clock to be honest. I can get a pack of RS4180BL from aliexpress or even ebay for a few euros but would have to wait for them to arrive from China.

I found a simple schematic for a Crystal Oscillator tester so I'm gonna build one tomorrow and then I can desolder that corroded looking one and test it just in case the amplitude really is too low.

I do have a couple more 25MHz crystal 'pulls' in my spares box, they are the two pin ones but the tall package, not the low profile type though i doubt that would matter.

Rich

[stj]

Re: H57H-AM2 Motherboard with CPU voltage problem

dish cleaning soap, boiling water from the kettle and a kitchen sink is my board cleaner.
the key is to quickly dry if afterwards - i use a fan heater - others use hair dryers - and other methods.

[piernov]

Re: H57H-AM2 Motherboard with CPU voltage problem

If the RTC clock was an issue the board wouldn't turn on at all. 25MHz is a typical clock for PCH, so that should be good too.

Not sure why CPU VCore would start at 0.9V instead of 1.1V though. Maybe something to look into, maybe not. CPU sets the VCore voltage, so it could be a CPU issue.

RAM doesn't matter at this point, memory controller inside the CPU is not initialized.

[dicky96]

Re: H57H-AM2 Motherboard with CPU voltage problem

I have a cheap used i3 gen 1 cpu on order from ebay, I'm trying to build up a stock of known good test processors and boards for each socket type anyway

I also ordered some RS4180BL from aliexpress as they were cheap. I had a good look around the chip today on my scope and it doesn't seem to be doing very much, most pins are static 3.3V or 0V or floating about 1V. Just four have oscillations on them, two of those connect direct to the Crystal. Shame I couldn't find a datasheet for RS4180BL though, it would be really useful.

So that lot will take some time to come from China, guess I will have to look at a few other boards I have in the meantime.