HDD GURU FORUMS :: View topic - Dead OCZ Vertex 4

perhaps L7 is broken open or something like that.

Hello, my Vertex 4 has just broken down, after connecting the power, the green diode does not light up, the disk is dead - interestingly, the disk starts when + 5V is applied to the right leg of the C185 capacitor, so it is rather without short circuits, I wonder if there is a problem with RT9991 control?

pepe wrote:

perhaps L7 is broken open or something like that.

L7 filters the incoming 5V supply. Therefore it must be OK. In any case, an open inductor would be unlikely.

fzabkar wrote:

pepe wrote:

perhaps L7 is broken open or something like that.

L7 filters the incoming 5V supply. Therefore it must be OK. In any case, an open inductor would be unlikely.

why MUST it be ok? it can break just as anything else can.
Since all the power comes through that, device could be dead if it is broken... unlikely things happen sometimes, so worth checking, it doesn't take more than a second.
would be my first step before analyzing the more complicated circuits...

L7 is on 5V supply line, so if it is open, all power is cut from the circuits, and in such case feeding 5V to ie a 3.3V line can make it alive for a short time for example, if the buck converters are cascaded.
i suspect some misunderstanding somewhere...

nope, i simply said it is worth checking, as it takes only seconds and can save a lot of other hassle if it is broken.
And i saw a few cases where the lower voltage converters were powered from 3.3V, not from the main input source.
On the other hand, it is also possible that if you rise the output of one of the controllers above the input level, it gets pulled up through the reverse diode of the output transistor, supplying power to the other converters .
just 2 scenarios where my consideration is not absurd.

pepe

ps: just repaired a motor driver system, where the break of the current sense resistor caused the whole microcontroller system to toast through protection diodes, as the VCC of the MCU was pulled higher through them. Kind of similar scenario here, just not that destructive as with 48V in the motor system...

okay, master, it's pointless coz you talk as if we were enemies...
i honestly wanted your oppinion but not in this style

pepe

Author:	PizzaAlways [ November 24th, 2020, 18:41 ]
Post subject:	Re: Dead OCZ Vertex 4
As I mentionned some of my measurements could be wrong, as I'm not used to do this kind of manipulation on components this small. I can redo any measurements you want, if that can help. As two of the memory chips are apparently overheating I hope they didn't get damaged beyond repair... Let me know what I can do to help. On a side note, I'm sorry for the numerous typos in my previous messages, I should have pay more attention and I will.

Author:	fzabkar [ November 24th, 2020, 20:28 ]
Post subject:	Re: Dead OCZ Vertex 4
Were the overheating chips the two hynix SDRAMs?

Author:	PizzaAlways [ November 24th, 2020, 20:47 ]
Post subject:	Re: Dead OCZ Vertex 4
No, it was two of the nand chips in the front. I don't know if any of the chips in the back were overheating as at this time as I didn't remove the back cover yet.

Author:	fzabkar [ November 24th, 2020, 21:10 ]
Post subject:	Re: Dead OCZ Vertex 4
I would retest the capacitors around the hynix SDRAMs, especially the 4 biggest capacitors.

Author:	orzech [ May 14th, 2022, 4:05 ]
Post subject:	Re: Dead OCZ Vertex 4
Hello, my Vertex 4 has just broken down, after connecting the power, the green diode does not light up, the disk is dead - interestingly, the disk starts when + 5V is applied to the right leg of the C185 capacitor, so it is rather without short circuits, I wonder if there is a problem with RT9991 control?

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Author:	pepe [ May 14th, 2022, 10:04 ]
Post subject:	Re: Dead OCZ Vertex 4
+5V should not be applied to the right side of C185 , that's probably 3.3 or even lower (i don't have a device at hand atm), but since it's an output of a DC-DC converter, should be lower than the input voltage (5V). So you might toast your ssd doing that. that's the bad news, the good one is that your ssd apparently works, and the problem is in the supply part, perhaps L7 is broken open or something like that. pepe

Author:	fzabkar [ May 14th, 2022, 14:53 ]
Post subject:	Re: Dead OCZ Vertex 4
pepe wrote: perhaps L7 is broken open or something like that. L7 filters the incoming 5V supply. Therefore it must be OK. In any case, an open inductor would be unlikely.

Author:	fzabkar [ May 14th, 2022, 15:01 ]
Post subject:	Re: Dead OCZ Vertex 4
orzech wrote: Hello, my Vertex 4 has just broken down, after connecting the power, the green diode does not light up, the disk is dead - interestingly, the disk starts when + 5V is applied to the right leg of the C185 capacitor, so it is rather without short circuits, I wonder if there is a problem with RT9991 control? Test for continuity between C185 and each of L2, L3, L4, L5 and L6. This will tell you which voltage is missing. Better still, just measure the voltages at each inductor.

Author:	orzech [ May 14th, 2022, 16:25 ]
Post subject:	Re: Dead OCZ Vertex 4
Thank you for your answer, I will check the continuity of individual coils, for sure after applying the power, there is only + 5V voltage to the branches, the rest of the voltage appears only after switching on (by shorting C185 with L7)

Author:	pepe [ May 14th, 2022, 17:37 ]
Post subject:	Re: Dead OCZ Vertex 4
fzabkar wrote: pepe wrote: perhaps L7 is broken open or something like that. L7 filters the incoming 5V supply. Therefore it must be OK. In any case, an open inductor would be unlikely. why MUST it be ok? it can break just as anything else can. Since all the power comes through that, device could be dead if it is broken... unlikely things happen sometimes, so worth checking, it doesn't take more than a second. would be my first step before analyzing the more complicated circuits...

Author:	fzabkar [ May 14th, 2022, 19:23 ]
Post subject:	Re: Dead OCZ Vertex 4
pepe wrote: fzabkar wrote: pepe wrote: perhaps L7 is broken open or something like that. L7 filters the incoming 5V supply. Therefore it must be OK. In any case, an open inductor would be unlikely. why MUST it be ok? it can break just as anything else can. Since all the power comes through that, device could be dead if it is broken... unlikely things happen sometimes, so worth checking, it doesn't take more than a second. would be my first step before analyzing the more complicated circuits... ??? Obviously it cannot be open, because simply connecting 5V to one of the outputs of the two DC-DC converters would then do nothing.

Author:	pepe [ May 17th, 2022, 7:26 ]
Post subject:	Re: Dead OCZ Vertex 4
L7 is on 5V supply line, so if it is open, all power is cut from the circuits, and in such case feeding 5V to ie a 3.3V line can make it alive for a short time for example, if the buck converters are cascaded. i suspect some misunderstanding somewhere...

Author:	fzabkar [ May 17th, 2022, 13:42 ]
Post subject:	Re: Dead OCZ Vertex 4
pepe wrote: L7 is on 5V supply line, so if it is open, all power is cut from the circuits, and in such case feeding 5V to ie a 3.3V line can make it alive for a short time for example, if the buck converters are cascaded. i suspect some misunderstanding somewhere... Nonsense. The misunderstanding is at your end.

Author:	pepe [ May 17th, 2022, 18:53 ]
Post subject:	Re: Dead OCZ Vertex 4
then what do i miss here? Code: 5V L7 SATA conn. >----UUU----> to dc-dc converter if L7 is open, no supply to dc-dc conv, so no joy...

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Author:	fzabkar [ May 17th, 2022, 20:14 ]
Post subject:	Re: Dead OCZ Vertex 4
My understanding is that the OP powered up the SSD, found that one of the converter outputs was missing, and then injected 5V into this missing output (C185) while the SSD remained powered up. You appear to be suggesting that, if L7 is open, it is still possible to bring the SSD to life by injecting 5V into that one output. Clearly that's absurd, for the reason you have just stated.

Author:	pepe [ May 18th, 2022, 5:23 ]
Post subject:	Re: Dead OCZ Vertex 4
nope, i simply said it is worth checking, as it takes only seconds and can save a lot of other hassle if it is broken. And i saw a few cases where the lower voltage converters were powered from 3.3V, not from the main input source. On the other hand, it is also possible that if you rise the output of one of the controllers above the input level, it gets pulled up through the reverse diode of the output transistor, supplying power to the other converters . just 2 scenarios where my consideration is not absurd. pepe ps: just repaired a motor driver system, where the break of the current sense resistor caused the whole microcontroller system to toast through protection diodes, as the VCC of the MCU was pulled higher through them. Kind of similar scenario here, just not that destructive as with 48V in the motor system...

Author:	fzabkar [ May 18th, 2022, 12:44 ]
Post subject:	Re: Dead OCZ Vertex 4
pepe wrote: nope, i simply said it is worth checking, as it takes only seconds and can save a lot of other hassle if it is broken. And i saw a few cases where the lower voltage converters were powered from 3.3V, not from the main input source. On the other hand, it is also possible that if you rise the output of one of the controllers above the input level, it gets pulled up through the reverse diode of the output transistor, supplying power to the other converters . just 2 scenarios where my consideration is not absurd. pepe ps: just repaired a motor driver system, where the break of the current sense resistor caused the whole microcontroller system to toast through protection diodes, as the VCC of the MCU was pulled higher through them. Kind of similar scenario here, just not that destructive as with 48V in the motor system... When you dig yourself into a hole, the prudent thing to do is to stop digging.

Author:	pepe [ May 18th, 2022, 12:59 ]
Post subject:	Re: Dead OCZ Vertex 4
okay, master, it's pointless coz you talk as if we were enemies... i honestly wanted your oppinion but not in this style pepe

Author:	fzabkar [ May 18th, 2022, 13:40 ]
Post subject:	Re: Dead OCZ Vertex 4
pepe wrote: okay, master, it's pointless coz you talk as if we were enemies... i honestly wanted your oppinion but not in this style pepe The proper thing for you to have done was to admit that you made a silly mistake, and then we would both have written it off as a brain fart. If instead you try to defend a brain fart, the smell lingers for a lot longer.

Author:	fzabkar [ May 18th, 2022, 18:50 ]
Post subject:	Re: Dead OCZ Vertex 4
pepe wrote: okay, master, it's pointless coz you talk as if we were enemies... i honestly wanted your oppinion but not in this style pepe I apologise. After further thought, here is my opinion, FWIW. As I understand it, you are now suggesting that the output of one converter is able to (unintentionally) power all the others via the forward biased body diode of its MOSFET chopper. I agree that this is plausible. However, I still reject your first idea that a single converter has been designed to power all the others by cascading the outputs into the inputs. This would place undue stress on that converter, plus it would make power management untenable, or at least very complicated. I have yet to see any SSD which has been designed in this way. I realise that USB-connected m.2 SSDs are a case where a 5V source is reduced to 3.3V via a single converter on the bridge PCB, and the 3.3V output is then further reduced internally by the SSD. However, a native USB SSD, if it exists, would not do it this way.