MSI B150M PC Mate, a shot in the dark?

[Uranium-235]

customer came to me with this board dead after 3 years of operation. They didn't warranty it even though the purchase date was within one day, according to them, it was 6 months out of warranty

I got him a PRO-VD, a board i've used for tons of customers many past three years. CPU and ram worked great

Power, No post, diagnostic LED's show CPU (which the CPU - i3-6100) did work in the new board just fine. Is there anyway to test this with no CPU? Think it could be a fet? These are small fets with a fairly big heatsink on there, but i'm not sure any heat will show with no CPU to pull current through them. Not even sure there will be voltage measured from the output vrm without a cpu. And if there is, How do I test these individual ones? They're so small, and very close together.

[piernov]

Re: MSI B150M PC Mate, a shot in the dark?

If a CPU VRM MOSFET was shorted the PSU would go into protection as soon as the board turns on.
Since the issue is that the board doesn't POST, you need a CPU in it to test.
First thing to try is to flash the BIOS.
Then check the CPU power rails (not sure what's on this board, maybe VCore, VCCIO, VCCSA).

Boardview for MS-7971 seems to be available but only on paid sites.

[Uranium-235]

Re: MSI B150M PC Mate, a shot in the dark?

this is no post, no video. I did some searching on how to flash with no post (i've done this before with corrupt HP's before from yesteryear). My search returned instructions on ASUS and gigabyte but no MSI

so other than physically unsoldering the bios chip and replacing it for a $15 one from ebay, any other idea?

edit: further research shows a JSPI header can flash the chip. Now all I need is the hardware

[momaka]

Re: MSI B150M PC Mate, a shot in the dark?

I'm with Piernov here - you need a CPU to test the mobo, and it's unlikely to be a CPU MOSFET issue.

It could be the BIOS, as he suggested.

But it could also be corroded contacts in the RAM slots. These days, many electronics use quite crap plating, so bad contacts are a fairly common problem. Removing and inserting the RAM a few times might just clean them enough.

And if you had a stock Intel push-pin -mounted heatsink on that CPU, you could have bad socket BGA too. When I used to work in a big PC store repair shop a few years back, HP would often send us refurbished mobos with flux around their CPU sockets. So I suppose that's not an uncommon failure point either. After all, those Intel stock push-pin heatsinks warp the shit out of most motherboards.

[Uranium-235]

Re: MSI B150M PC Mate, a shot in the dark?

I'm with Piernov here - you need a CPU to test the mobo, and it's unlikely to be a CPU MOSFET issue.

It could be the BIOS, as he suggested.

But it could also be corroded contacts in the RAM slots. These days, many electronics use quite crap plating, so bad contacts are a fairly common problem. Removing and inserting the RAM a few times might just clean them enough.

And if you had a stock Intel push-pin -mounted heatsink on that CPU, you could have bad socket BGA too. When I used to work in a big PC store repair shop a few years back, HP would often send us refurbished mobos with flux around their CPU sockets. So I suppose that's not an uncommon failure point either. After all, those Intel stock push-pin heatsinks warp the shit out of most motherboards.

I checked the ram in all four slots. if it was a ram problem it should have had the ram led lit (past CPU). I'll look around the cpu but these MSI pro boards are very solid, i've never had an issue with flexing, even though it was a pushpin heatsink.

I might end up getting one of those $5 flashers off ebay. Requires me to desolder the bios chip and solder it to the flasher, and back, but the chip almost looks like it was soldered manually, very wide board trace contact. Looks easy to undo with some flux

[staze]

Re: MSI B150M PC Mate, a shot in the dark?

I checked the ram in all four slots. if it was a ram problem it should have had the ram led lit (past CPU). I'll look around the cpu but these MSI pro boards are very solid, i've never had an issue with flexing, even though it was a pushpin heatsink.

I might end up getting one of those $5 flashers off ebay. Requires me to desolder the bios chip and solder it to the flasher, and back, but the chip almost looks like it was soldered manually, very wide board trace contact. Looks easy to undo with some flux

You ever figure this out? Got a board in this exact same situation... CPU tests good (alternate CPU even). Ram. PSU. GPU. all good... can't get board to post. Even found instructions for doing USB recovery, no luck (USB never powers up)

[Uranium-235]

Re: MSI B150M PC Mate, a shot in the dark?

I never got around to re-flashing the bios chip yet. I will try after certain expenses are resolved