SA400S37/240 Kingston SSD GB - Stopped working - IC get hot

[Spotmen]

Hi,

I am not sure how to fix this ssd. 5V rail goes under that chip called "AFNM 899" It's connect to the "body" of that chip, I've removed it to control. From thermal camera is see that chip getting hot and the little component (marking 12x) getting hot as well. I can't find where voltage is going. If I google AFMN I get to a Maxim chip for 12V... can't be that one.

Any idea ? Should I try to replace it ? and what is the little "resistor with 12X" ?

regards
Spot

Attachments

[Lardman]

Is it a
MP5010B
http://www.mouser.com/ds/2/277/MP5010B_r1.0-480360.pdf

[Spotmen]

Thank you very much. Do you think I should replace it ?
How did you find out it was that chip from AFMN marking ? I have another ssd with marking AFNG 817, how can I check if it's compatible ?

[fzabkar]

Mate, forget the thermal camera. Break out a multimeter and measure the resistance between ground and the output of that IC. I'm betting that you will find that one of the downstream components is shorted. The IC is getting hot because it is probably trying to drive into a short circuit.

As for part markings ...

http://markingcodes.com/search/c/afn

[fzabkar]

PCB protection devices - Electronic Fuse:
https://www.hddoracle.com/viewtopic.php?p=8872#p8872

[Spotmen]

Thank you both for your quick reply.

So If I lift the little component (mark 12X... current limitator ??) next to the limitor switch, then I see 5V on output, so that IC is working as Fzabkar tought.
Now to find the culprit, I should inject 1 V after the 12 X "resistor" while It's still lifted so the bad component will get hot ?

If I measure the caps around, they are all shorted.

Thanks

[Spotmen]

I tried to remove the "resistor x12" and the cap. before they were all shorted but that doesn't help. If I remove the resistor, I can measure 5V on one side and the other side is shorted to gnd. So the voltage must go somewhere else but I can't find where.

Attachments

[Lardman]

I can't see anything via potato vision.

If you've pulled it and your short on the downstream but not the up, then work your way towards the pmic, Assuming your pmic outputs aren't grounded (have you checked them) there won't be a lot options for where the short could be.

If you just want the "please bro" solution break the circuit at the fuse and pulse 0.8v on the downstream side and see what's getting hot on the thermal cam.

[fzabkar]

Mate, get a real camera and show us a photo that we can use.

Hint: If you can't see the part markings in your photo, then neither can we. What are we supposed to do with black rectangles?

[fzabkar]

Is this the "X12 resistor"?

https://m.littelfuse.com/products/polyswitch-resettable-pptcs/surface-mount/minismd/minismdc125f_2.aspx

If so, then removing it will disconnect all power to the SSD. It's not the problem (it's a resettable fuse, aka polyswitch).

[Spotmen]

Yes X12 seems to be resettable fuse, when I disconnect it, I don't get anything. the other IC is MRVL G868B 632GAD.
I'll do add measure on those pics.

Attachments

[fzabkar]

88PG868, Marvell, dual step-down converter, I2C, 2.7V - 5.5V in, 3A & 1A, 1.1MHz, QFN-24:
https://web.archive.org/web/20190609080912/www.marvell.com/power-management/assets/Marvell-DC-DC-Power-Regulators-Product-Portfolio.pdf

@Lardman has already advised you how to proceed. You need to measure the resistance between the 5Vin and 5Vout pins of the AFN chip. If there is a short to ground at the input, then the chip is bad. If there is a short to ground at the output, then you need to remove the chip and retest for shorts. If the short goes away, then the chip is bad. If the short persists, then there is a fault downstream.

In any case, you can bypass the AFN chip by bridging 5Vin to 5Vout.

[Spotmen]

thank you. I'll try tomorroow.

[Spotmen]

ok, took forever to fix it but finally it's done. The problem was on PCB. It was bended at one corner. I didn't pay attention. so VCC and GND were touching each other.

Thank you for all your help.