HDD GURU FORUMS http://forum.hddguru.com/ |
|
Samsung EVO 850 - workstation won't boot http://forum.hddguru.com/viewtopic.php?f=10&t=42976 |
Page 4 of 4 |
Author: | Lardman [ January 29th, 2023, 17:11 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
DRUG wrote: @Lardman I am assuming he is connecting on the right place. It sounds awfully like the terminal is connected to the safe mode pins to me.
|
Author: | DRUG [ January 29th, 2023, 17:21 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
Lardman wrote: DRUG wrote: @Lardman I am assuming he is connecting on the right place. It sounds awfully like the terminal is connected to the safe mode pins to me.I'm re-reading the conversation, if he is shorting the 2 pins next to JTAG that's safe mode, the next two pins are UART. Let's hear what he says. |
Author: | fzabkar [ January 30th, 2023, 1:06 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
ISTM that you have mixed up the UART and Safe Mode pairs. The pair closest to the JTAG pads is Safe Mode. At least that would be consistent with Ace's video and @sourcerer's manual (even though they are different models). Shorting the UART pads should do no harm, though, if they are indeed the UART. In fact, those two smaller pads may not be UART pads. One appears to be connected to ground. |
Author: | Lardman [ January 30th, 2023, 4:48 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
I just popped open a 120gb 850 evo I bought for r&d. Just to be difficult the layout is completely different, but I have confirmed the 2 smaller pads (mine are underneath) are definitely safe mode which are the ones silcontool has marked as such. I'll have a poke around for terminal when I get 5 mins. |
Author: | fzabkar [ January 30th, 2023, 14:45 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
Lardman wrote: I just popped open a 120gb 850 evo I bought for r&d. Just to be difficult the layout is completely different, but I have confirmed the 2 smaller pads (mine are underneath) are definitely safe mode which are the ones silcontool has marked as such. That would make sense. One pad would be grounded, the other would be pulled up to the Vio supply via a resistor. Hopefully those other two pads are connected the controller's GPIO pins and not to a supply rail. |
Author: | Lardman [ January 31st, 2023, 7:05 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
fzabkar wrote: Hopefully those other two pads are connected the controller's GPIO pins and not to a supply rail. I hooked terminal up to the extra pads and got nothing even with an added earth bond in case it was floating, thought it might be the cheap uart at first but get equally nothing using the ace adapter. The drive here is fine, and still working despite me fumbling about with the adapters set from 1.8v to 5v so I assume the OP's wont have suffered either.
|
Author: | pepe [ January 31st, 2023, 7:13 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
uart is not routed out to those pins as far as i remember. |
Author: | Lardman [ January 31st, 2023, 10:02 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
pepe wrote: uart is not routed out to those pins as far as i remember. I couldn't be sure I'd found it, I found a candidate pad for TX using the meter after scratching away some coating on the back below the crystal but without something like jtagulartor I can't confirm.
|
Author: | fzabkar [ January 31st, 2023, 13:19 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
@silcontool", are either of those "UART" pins next to the JTAG row grounded or shorted to ground? |
Author: | silcontool [ January 31st, 2023, 14:29 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
fzabkar wrote: @silcontool", are either of those "UART" pins next to the JTAG row grounded or shorted to ground? No. Neither of the 2 pins is grounded. Both pins have +1.87V on them. |
Author: | fzabkar [ January 31st, 2023, 14:40 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
silcontool wrote: fzabkar wrote: @silcontool", are either of those "UART" pins next to the JTAG row grounded or shorted to ground? No. Neither of the 2 pins is grounded. Both pins have +1.87V on them. Then I guess your drive has failed coincidentally, not because of any user error. I don't know which tools or skills you have, but you would need to determine whether any of those 3 capacitors is responsible for the short, or whether the load switch IC itself is shorted to ground. If it's anything else, then I don't know. One way to locate the short would be to check the temperature of each cap to see if it getting hot (a finger test may suffice). A better way would be to remove them one by one and retest the circuit for shorts. |
Author: | silcontool [ January 31st, 2023, 23:52 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
I'm going to buy another 850 EVO ssd to compare with and help figuring out a probable cause of the trouble. Any suggestions for tools I must have would be appreciated. Thanks |
Author: | fzabkar [ February 1st, 2023, 2:22 ] |
Post subject: | Re: Samsung EVO 850 - workstation won't boot |
I am not aware of any DIY tools to fix firmware problems in Samsung SSDs. At the moment you have a hardware problem that is relatively simple. Ideally you would use a hot air station to remove the caps and possibly the load switch. However, even if you resolve the hardware problem, you will then be back to the original firmware problem. |
Page 4 of 4 | All times are UTC - 5 hours [ DST ] |
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |