MSI B85-G43 GAMING no Vcore voltages.

[taxxin]

I have a B85 Gaming board here with fancy extruded dragon heatsinks, so the guy i got it off was running a gaming I7 not sure if its a K model or not? but its possible there was some overclocking going on.

Symptoms:

• With GPU and ram inserted, board can start up and stay on, I have a Post Card here TP611 or whatever and it reads 0.0 the whole time no post codes. from standby to on there is no change in LEDS, just PCIRST which is always on.
• Probing around in ON state I can see Most voltages are present, 3.3v, 5v, 1.5v PCH is receiving its 3.3vSb and 1.06V on the core voltage, slightly warm to the touch.
• No substantial Vcore voltages,
• CPU_IO reads 0v,
• CPU_CORE3 0.7v,
• CPU_CORE2 0.6v
• CPU_CORE1 0V
• CPU_VCOMP 0V
• CPU_VCCIN 0v
• CPU_VCCIO also 0V
• Probing around on the mosfets show a steady 12v on the high side of the mosfet with 0v on the drain, this suggests that they are not being activated by the driver?
• I also probed around for resistance with the CPU removed, 100-200kohm on some points of the mosfet im guessing the 12v rail and about 3-5kohm on the other side which is probably the VCORE side. No obvious looking shorts.

Things ive tried:
Removed and flashed bios chip with latest MSI bios.

So It would be handy if anyone here had schematics for this board, but if not I might start with looking at the datasheets for the mosfet drivers on the Vcore. I would like to know exactly why they would not be activating the mosfets gates and whether or not some kind of short circuit protection is in place. Or even see try to see if the drivers themselves have failed.

Please let me know if there is anything that i may have missed?

[re-atari]

Re: MSI B85-G43 GAMING no Vcore voltages.

Just checking, but you did connect your POST card to the TMP or LPC_Debug connector, right? On MSI boards, they only work on TPM or LPC_Debug. When inserted in PCIe connector the POST card display just shows '00' with the 2 decimal points lit alternating.

[taxxin]

Re: MSI B85-G43 GAMING no Vcore voltages.

Just checking, but you did connect your POST card to the TMP or LPC_Debug connector, right? On MSI boards, they only work on TPM or LPC_Debug. When inserted in PCIe connector the POST card display just shows '00' with the 2 decimal points lit alternating.

I have tried a small pin connector on the bottom on the board labelled JTPM1 which i am assuming is the TPM port, its also smaller than the rest of the connectors making it unsuitable for USB connections and such. There is also another one called JSPI1 which i am assuming is the connector for flashing the BIOS via SPI interface. Ive tried both orientations and both do light up just the same.

I have not tried the PCIE slot though perhaps i should?

[taxxin]

Re: MSI B85-G43 GAMING no Vcore voltages.

I have taken some photos of what seem to be the mosfet drivers for this board, i guess the first step is to check that they are all receiving their appropriate VCC voltages

[taxxin]

Re: MSI B85-G43 GAMING no Vcore voltages.

Found Schematics and Possibly the correct datasheet for one of the controllers, i found it quite difficult to pull a datasheet based on the laser etched markings on the chips

[taxxin]

Re: MSI B85-G43 GAMING no Vcore voltages.

I found what seemed to be a short between two pins in the main cpu phase controller, UP1649Q so i hit it with the hot air and some flux and it seems that VCORE has reappeared. 1.7v thoughout the VCORE and about 0.6 -1.0v from each of the 4 cores. previous to this the CPU was cold to the touch now its getting quite hot after the VCORE returned.

Stuck the post card in through the JTPM connector down the bottom and all im getting is 00 with no flashing decimal points the only leds that are lit are PCI RST.

With the Card in the PCI or PCIE slots i get three lit LEDS 3VSB, PCI RST and PCIE RST. also no codes but a blinking decimal point.

Could i have damaged the LPC/SIO or even the POST card by having it in backwards? there is 3v, 5v and so on in this connector and I fear that having it in the wrong hole will hurt something.

I get no response from the keyboard, no lights for the caps lock button. NO vga output but i am getting 5v out from all the usb connectors.

So latest development, Ive come to believe that the SIO chip is faulty mainly because it no longer works after putting the hot air to it, no more 3.3v and no more power to reset button when i leave the power on jumped. however its still getting power to the chip via 3.3v and 5v and so on. so ive ordered another one from there https://shop.ectransistors.com/1-PCS...9-IC-CHIP.html dont know if its a scam website or not, but they seem to be the only people on google selling this SIO chip.

Hopefully it should solve my problems completely. the only other thing that could be a problem is the PCH chip (southbridge) doesnt seem like anything is physically wrong iwth it but i have no real way to test it out

[re-atari]

Re: MSI B85-G43 GAMING no Vcore voltages.

I have tried a small pin connector on the bottom on the board labelled JTPM1 which i am assuming is the TPM port, its also smaller than the rest of the connectors making it unsuitable for USB connections and such. There is also another one called JSPI1 which i am assuming is the connector for flashing the BIOS via SPI interface.

I have not tried the PCIE slot though perhaps i should?

Correct, JTPM1 is the TPM connector, JSPI1 is the connector used for flashing the BIOS flashrom. Did you insert the POST card the right way round on the TPM connector, as in pin 1 on pin 1?

The doc's with my POST card state that on MSI boards it only gives out POST codes when inserted on the TPM connector. Only on Gigabyte mainboards is the POST card to be inserted in a PCIe connector. This appears to be true, as on my MSI X370 mainboard my TL611 only gave POST codes when inserted to the TPM connector and nothing when inserted in a PCIe connector.

[taxxin]

Re: MSI B85-G43 GAMING no Vcore voltages.

Correct, JTPM1 is the TPM connector, JSPI1 is the connector used for flashing the BIOS flashrom. Did you insert the POST card the right way round on the TPM connector, as in pin 1 on pin 1?

The doc's with my POST card state that on MSI boards it only gives out POST codes when inserted on the TPM connector. Only on Gigabyte mainboards is the POST card to be inserted in a PCIe connector. This appears to be true, as on my MSI X370 mainboard my TL611 only gave POST codes when inserted to the TPM connector and nothing when inserted in a PCIe connector.

okay thats good to know, I have the same post card posting up codes on another motherboard running on the PCI slot, so its probably still good. I had a suspicion that the SIO chip on this board is on its way out, looking and the schematics it has the LPC comms lines running right to this chip so im quite sure that the SIO handles post codes. replacing it will hopefully give me a better picture of whats happening.

[dicky96]

Re: MSI B85-G43 GAMING no Vcore voltages.

I don't know specifically about MSI boards but I did note that on ASUS Tuf Z270 putting the POST analyzer on the TPM pins the wrong way round didn't do any harm. In both orientations the LED display lit up but with it the wrong way round it was stuck on 00 and with it the right way round I get POST codes displayed

[taxxin]

Re: MSI B85-G43 GAMING no Vcore voltages.

I don't know specifically about MSI boards but I did note that on ASUS Tuf Z270 putting the POST analyzer on the TPM pins the wrong way round didn't do any harm. In both orientations the LED display lit up but with it the wrong way round it was stuck on 00 and with it the right way round I get POST codes displayed

well thats quite a relief to know, I tried the same post card on another older motherboard through the PCI slot and it seemed to work fine

[taxxin]

Re: MSI B85-G43 GAMING no Vcore voltages.

A little update, So the Nuvoton SIO chip arrived and i had a shot at trying to put it in, lucky for the me the backside of the board didnt have any capacitors or SMD components so i put it in direct contact with my 300w SMD heater, on the top i fluxed it and hit it with the hot air gun. sucessfully removed the chip without damaging anything.

Next up i decided to clean the solder pads up with my iron, i had it set to max and forgot that i still have the smd heater on and it was too hot and instantly oxidized the sodder, and actually ended up pulling one of the pads up off the pcb!! so anyways i turned off the heater and turned the iron down to 250C and cleaned the rest of the pads relatively easily,

I check the pad that i pulled off was pin 6 GP07 gpio or something like that according to the schematics it was not connected? it shows the pin out and leads to an X?? im assuming this is not connected? so i proceeded anyways because it seemed like a non critical pin.

So anyways now i tried to put the chip back on and halfway while trying to align the chip delicately with tweezers I had the hot air going 500C supposedly, and i heard that bacon crackle. I think perhaps the chip released its inner humidity by cracking.

So now its back together the symptoms are no power on when shorting the power pins Post card reads 00 with PCIE reset on. power gets its 5v. also noticed that the PCH core voltage used to be 1.3v and is now 0.39v on standby.

What do you think? over cooked the SIO chip? order another one? its gonna be another $15 bucks and 2 weeks wait for another.