Need help with a Crucial SSD, short circuit in 5v line

[bidomo]

Hey everyone!

Well, I ruined a pair of hard drives, because I accidentally shorted the 5v line in a SATA molex, so both hard drives are unresponsive...

Well, here I'm gonna talk about my SSD, its a Crucial M4, but I haven't found someone who could fix it, or they want me to send it overseas, so, better try my luck If someone could help me maybe...

The SSD just start building up some heat in an specific area on the drive, and nothing else.

The picture with the zoomed area is where the heat builds op, don't know if it is normal











Could this possibly be fixed?

Any help will be appreciated.

[fzabkar]

I don't see any protection on the 5V supply other than the zero-ohm resistors between the SATA connectors and the controller. I would start by measuring their resistances.

I would also measure the resistance between ground and each of the voltage test points (2V5, 1V0, 1V5, 3V3, 5VF, etc).

[fzabkar]

The chip in the hot area is a triple switchmode regulator. It probably generates the 2.5V, 1.0V and 1.5V supplies.

LTC3545, Linear Technology Corp, Triple 800mA Synchronous Step-Down Regulator, 2.25MHz, 2.25V to 5.5V Input, marking LCSR:
http://www.linear.com/docs/26043

The 16-pin chip on the other side of the PCB appears to generate the 3.3V for the NAND array. I can't see its markings, although its logo would suggest that it is another Linear Technology part.

I would also examine the chip adjacent to the 5VF test point, plus the small chips to its right.

These chips would probably be available for a few dollars from places like mouser.com or digikey.com.

[bidomo]

The zero ohm resistor is ok, will check the voltage test points

[MarkGreenwood (KE)]

Its usually the regulator with these..

[angleton]

I've actually run into a very similar problem. I have a previous gen C300 (very similar PCB) whose 0-ohm jumper from the 5v rail blew open like a fuse. I replaced that guy (with an actual fuse), and now only voltage test points that are giving me wrong values are the 5VF, 1V0, and 2V5 around that regulator area; all three of those points are shorted to ground somewhere and registering 0V. I haven't pinned the culprit down yet myself, and I'm wondering if you've made any more headway on this.

[fzabkar]

@angleton, I suspect that "5VF" is a filtered +5V supply. I would measure the voltages around this test point. It appears that the +5V input disappears somewhere in this area.

Also, I would check all the other zero-ohm resistors at the SATA power connector, if you haven't done so already.

As for the other voltages being "shorted to ground", have you actually measured the resistances between these points and ground?

[angleton]

Good point yeah, I was jumping ahead of myself thinking they were shorted. I'm still digging, but the resistance values I'm seeing are:

5VF: This guy seems to peak out at 10M ohms.
2V5: 80K ohms
1V0: 60 ohms

With it off for a bit now, the 5VF is around 7.5M, the 2V5 has dropped to around 77K, and the 1V0 to around 55.

The other 0-ohm resistors are good - no resistance.

[angleton]

Oh wow, correction: 5VF is at 10 ohms (not 'M' ohms) with power, and it shoots way up into the millions after the power is off.

[fzabkar]

Measure the Vin and PVin voltages at the LTC3545 regulator. They should be +5V.

If they are missing, then it will probably be because 5VF is not present. In fact 5VF may be the chip's supply voltage. It would help if you could supply a detailed photo or scan of this area.

Attachments

[fzabkar]

Oh wow, correction: 5VF is at 10 ohms (not 'M' ohms) with power, and it shoots way up into the millions after the power is off.

You must NOT measure the resistances when the board is powered on.

BTW, you must be careful NOT to short adjacent pins with your probe when the drive is powered on. Doing so will result in catastrophic damage.

[fzabkar]

Could you carefully measure the voltages indicated in the regulator photo?

Could you also measure the voltages around the "5VF IC"?

Attachments

5VF_IC.jpg (36.36 KiB) Viewed 24688 times

[bidomo]

I'm really sorry for the late response...

Well, I've tested the regulator voltages, the upper one is giving me 4.70, the one below is giving me 4.76.

As in how to measure the voltages around the 5VF, I wouldn't know how to do it properly, I was trying to read the 5VF IC with a magnifier, but I couldn't read it, instead, I've noticed the IC to be a little inflated, I might be wrong, I would try to upload a high res picture as soon as possible.

[bidomo]

I haven't got my hands on a camera yet, but the inflated aread in the 5VF can be felt to the touch, and can be seen clearly under the daylight.

[fzabkar]

A CCD scanner (not CIS) produces much better results than most cameras.

[bidomo]

I'll have to assume my scanner is CIS, because the scanned image was horrible (photosmart multifuctional), I guess I will have to try some other scanners...

[HaQue]

If you put the PCB on a table near a white wall, and shine a desk lamp on the wall, not the PCB, you can get great pictures from an iPhone quality camera. I take virtually all my pictures with a 4S. I take anything that needs better with a new canon EOS.

trick is not to take the picture too close.

[bidomo]

Well, I don't have a big phone right now (battery failed in my moto g), so I used my sister Galaxy 3 mini, but I don't have a good lamp, well, at least I believe the problem can be appreciated in this photo

[fzabkar]

According to the following thread, the "5VF" device is a power supply supervisior IC.

http://www.eevblog.com/forum/repair/cru ... icron-c400)/

TPS3801T50DCK, Texas Instruments, marking AVI, SOT23, 4.0V / 25ms PSU supervisor, 7V abs max:
http://www.ti.com.cn/cn/lit/ds/symlink/tps3801-01.pdf

If that is the only problem, then the repair should be relatively easy. A similar IC can be had for less than $1, or you could even manipulate the 5VF output (5V Fail) manually.

Attachments

4V_supervisor_pinout.jpg (11.64 KiB) Viewed 23702 times

4V_supervisor_block_diag.jpg (38.18 KiB) Viewed 23702 times

[bidomo]

Ok, So I've measured the IC (leg 1 and 4), it's reading between 4.27V and 4.35V, so, is the oscillator part to be blamed?

I'll ask some friend about this, maybe he could be able to help me with this.

I would be happy to take this drive to a experienced technician, but there's no such a thing around here, when it comes to SMD components, nobody knows nothing, a few good techs aren't so far, but they can't be trusted at all (they will rip me off both with my money and drive as soon as they can confirm it to be working again, it's like a mob zone)