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 Post subject: Re: Need help with a Crucial SSD, short circuit in 5v line
PostPosted: June 25th, 2015, 23:07 
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You should be measuring 5.0V between those two IC pins. That's the SSD's supply voltage.

What voltages are you measuring at the 2V5, 1V0, 1V5, and 5VF test points? Also measure the voltage at the 1.0uH coil near the 88SS9174-BLD2 flash controller.

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 Post subject: Re: Need help with a Crucial SSD, short circuit in 5v line
PostPosted: June 26th, 2015, 0:10 
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Voltages are as follows

2V5 0.19v - 0.20v
1V0 0.61v - 0.62v
1V5 0.01v
5VF 3.30v - 3.31v (this is the actual test point, IC leg was 4.35)
1.0uH coil 3.30v - 3.31v


I'm using ground from the JTAG header and from the 5V test points near the LCT regulator, both give the same reading.


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 Post subject: Re: Need help with a Crucial SSD, short circuit in 5v line
PostPosted: June 26th, 2015, 3:45 
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If your PSU is delivering 5V at the SATA terminals but only 4.35V at the TPS3801T50DCK IC, then something weird is going on with your PCB. Otherwise, if the PSU is delivering 4.35V at the SATA terminals, then it is either a lousy PSU, or it is improperly loaded. This is what can happen if the 12V rail of a 5V/12V PSU is unloaded, as would be the case if the SSD (a 5V-only device) is the only device attached to the PSU.

Anyway, the 3.3V supply is working. Just for the sake of completeness, what are the markings on the 16-pin LT chip on the underside of the PCB?

Your most recent voltage measurements would suggest that the LTC3545 chip is faulty, or that its 3 regulators are not being switched on, or that one or more of its outputs are overloaded.

Can you measure the resistances between ground and each of the 1.5V, 1.0V, and 2.5V test points (with the power switched off)?

Can you measure the RUN1/2/3 and Reset voltages?

Can you tell me the markings on the serial flash memory (?) and the 5-pin chip near the 25MHz crystal?


Attachments:
flashmem.jpg
flashmem.jpg [ 21.46 KiB | Viewed 2922 times ]
Regs_Run.jpg
Regs_Run.jpg [ 183.02 KiB | Viewed 2922 times ]

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 Post subject: Re: Need help with a Crucial SSD, short circuit in 5v line
PostPosted: June 26th, 2015, 16:17 
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Ok, this is getting a bit weird...

I don't know if RUN1..3 have to be measured in that exact order, but I did it that way, then waited for the SDD to cool and discharge to take some other readings.

Here goes:
Resistances:
2V5 24.9~25
1V0 25.6
1V5 12.2

Voltages
RUN1 it tilts from 1.90 to 3.27 till it sits stable there (3.27)
RUN2 This one is a bit of a wildcard, it could be totally stable at 1.40, then go all the way up to 3.27 and stay
RUN3 Same as RUN2
RESET I never got anything concrete from this one, 1.40, 2.90, 1.30, 1.0, seems to change as long as power keeps running

RUN1..3 :As soon as 1 of them reads 3.27 all of them will do the same, but if I remove GND, they will start tilting till they get to 327

Also, as the time runs and the device is still powered, some other voltages will change
2V5 0.12
1V0 0.49
1V5 0
5VF stable 3.30 as before

AVI Vdd, Coil, will remain stable

The 16pin chip reads 3412A N2962
The supposed flash chip, well, I'm not completely sure, will try some other lamp/light magnifier combinations, but I read C075 so far

As for the testing suply, I'm using both a PC PSU rated 250W (from an old dell computer), and a standalone supply for a USB HDD.
After you told me the PSU could possibly be unloaded, I added another hard drive and some fans.
The reads remain almost the same even in the different time lapses, if I measure the SATA molex it will read 5.0~ in both PSUs, but as soon as I connect the SSD the will read 4.75 aprox (from the connected molex), all other molex in the Dell PSU will read 5.0~ correctly.


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 Post subject: Re: Need help with a Crucial SSD, short circuit in 5v line
PostPosted: June 26th, 2015, 17:55 
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I don't understand what you are doing when you say "if I remove GND", but the RUN voltages are OK. That would suggest that the LTC3545 IC is faulty.

The RESET voltage should be sitting at a constant high level, so there is something wrong there. I can't identify the "CC" component, so I'm not sure what part it plays.

I would try to source the two faulty ICs (LTC3545 and TPS3801T50DCK) from places like Farnell, RS Components, Newark, Digikey or Mouser.

Just for completeness ...

LTC3412A, Linear Tech, 3A, 4MHz, Monolithic Synchronous Step-Down Regulator:
http://cds.linear.com/docs/en/datasheet/3412afe.pdf
http://www.farnell.com/datasheets/1692450.pdf

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 Post subject: Re: Need help with a Crucial SSD, short circuit in 5v line
PostPosted: June 26th, 2015, 18:11 
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Just for completeness ...

SN74LVC1G07, Texas Instruments, Single Buffer/Driver With Open-Drain Output, marking C075, DBV package:
http://www.ti.com/lit/ds/symlink/sn74lvc1g07.pdf

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 Post subject: Re: Need help with a Crucial SSD, short circuit in 5v line
PostPosted: June 26th, 2015, 23:01 
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I'm really sorry, but I wasn't clear enough when I said "if I remove GND", what I was trying to say is, I've been taking all of my reads without moving the multimeter from the ground in between reads, but if I removed it from ground, and try to read the voltage again, it will give me a different value.

Well, I will have to buy those 2 ICs, and then will see what happens.

Thanks for the help, I hope I can get this budy to work again.


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 Post subject: Re: Need help with a Crucial SSD, short circuit in 5v line
PostPosted: July 2nd, 2015, 19:46 
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Coul I possibly use another IC instead of the 3545? Only found a 5 pack, and what use do I have for the other 4?


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 Post subject: Re: Need help with a Crucial SSD, short circuit in 5v line
PostPosted: July 2nd, 2015, 23:59 
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well nevermind my previous post, it seems I've found both ICs in digikey, but there are a lot to choose from, I guess I will need a bit of help choosing the right parts...

http://www.digikey.com.mx/product-searc ... 3801T50DCK

http://www.digikey.com.mx/product-searc ... ?k=LTC3545


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 Post subject: Re: Need help with a Crucial SSD, short circuit in 5v line
PostPosted: July 3rd, 2015, 16:16 
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Look up the full part number in the datasheet, determine the package style, and then compare its dimensions against the original part. Make sure you get the LTC3545 part, not the LTC3545-1. The "IUD" version appears to have industrial temperature specs, so the "EUD" part should be OK for you.

The following appear to be the correct choices, but please verify them for yourself.

http://www.digikey.com.mx/product-detai ... -ND/416765

http://www.digikey.com.mx/product-detai ... ND/1814424

The only other concern I have is in regard to the "CC" component. I don't recognise it, nor do I understand its function. :-(

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 Post subject: Re: Need help with a Crucial SSD, short circuit in 5v line
PostPosted: November 25th, 2017, 0:33 
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MT41J128M16HA-15E:D, Micron, marking D9LGQ, FBGA96, DDR3-1333 SDRAM, 1.5V, 1.5ns, 16M x 16 x 8 banks:
https://www.micron.com/~/media/documents/products/data-sheet/dram/ddr3/2gb_ddr3_sdram.pdf

M25P80V6G, STMicroelectronics, serial flash memory, 8-VFQFN, "V" = 2.7 - 3.6V:
https://www.jameco.com/Jameco/Products/ProdDS/321672-DS09.pdf

MT29F128G08CFAAB, Micron, L74A NAND flash

SN74LVC1G04, Texas Instruments, marking CC, single inverter gate, 1.65V - 5.5V, X2SON(4):
http://www.ti.com/lit/ds/symlink/sn74lvc1g04.pdf

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