Hi everyone. I'm new to the site, but have found it very helpful in fixing the other drives that suffered the problem I will soon describe, and in identifying components of this MX300 that I'm still having problems with. I'm hopeful that you'll be as understanding and as helpful as I've seen so far, but please feel free to redirect me if I have missed something in my search and this has already been covered before!
I have a Crucial MX300 2.5" form factor, 275GB, with model #: CT275MX300SSD1 (if you need any other numbers, let me know!).
I suspected I had an underperforming PSU, and in the process of being a good debugger and isolating the problem, I changed out /only/ the PSU and not the cables (several of you know where this is headed), and promptly fried my hard drives' components because there is apparently no standard pinouts for PSUs, and I gave my drives 12V to their 5V rails. Fortunately my Samsung SSD had protection and survived unscathed (I think), and my HDDs only had their TVS diodes shorted for an easy fix. The MX300 was another story entirely, with at least 2 components letting the smoke out. I am shocked there was no protection closer to the supply rails, but I'm no circuit designer, so /shrug.
There were two clearly blown ICs, which due to similar layouts and the photos revealing letters that I'd previously been unable to see, and thanks to
this lovely post, I determined were buck converters (
TLV62080-ish). I figure, "hey, I can try to fix that." Digikey's out of them, but "maybe I can just hook up a voltage source or two once I figure out what they were set to." Unfortunately, without knowledge of the circuit, I'm not sure if there's anything else wrong or things that I might expect might be wrong, or whether or not what I'm reading from my multimeter makes sense. So I'm hoping to get some clarity on this circuit from you experts.
Here are my main issues so far:
- I don't know the /intended/ local circuit around the chips. This prevents me from calculating what the output voltage would be as configured by the resistors.
>>> Right now it appears the resistors connected to the feedback pin are just parallel connected to ground which seems weird, but I noticed that the larger capacitor seems to be shorted (oh, now that I'm thinking about it, maybe that's an inductor? I don't suppose there would be any reason for the cap to fail, and that would explain the 0 Ohm reading... Does anyone know a good way to tell the difference with a basic multimeter?)
- The resistance readings I'm getting on the resistors is different for each of the regulators, but I don't know if that's due to the damage just changing the circuit config or not.
After running into these roadblocks I requested some quotes from some companies around this SF Bay Area, and promptly concluded that I could not afford the $650+ they were expecting it to cost, so I'm hoping to solve this problem myself, even if I have to pay another student (hopefully way less) who has steadier hands for the fine soldering.
So question #1: Does anyone know what each of the chips are programmed to output?
Question #2: Does anyone know of other components that I should check that they would expect to be damaged?
Question #3: Assuming I can get the parameters of the converters and their circuits, if I can't get my hands on any more of those buck converters (apparently there's a 38 week lead time on digikey...), I could try just hooking up some voltage supplies. But I don't know whether or not using an external voltage supply would damage anything. Would it?
Question #4: If it would be "safer" in terms of data stability to just transfer over to a replacement PCB (versus possibly getting the voltage wrong or missing another problem with the circuit), what components would I have to transfer? I know for HDDs you need to pair the disks with the "BIOS chip" when replacing a board; is there a similar chip that handles addressing for SSDs (and anything else)?
(As a tangential aside, now that I've transfered the data off of them, I'd like to keep using the other affected HDDs for other purposes, but with new PCBs. However, I don't want to transfer their BIOS chips to the replacement boards. If I just put brand new PCBs in, I should be able to just format the drive and use it normally assuming I don't need the old data on them anymore, right?)
I've attached photos (and realized the pixel 5a lens is really crap with macro apparently), and am happy to take more photos, provide more information, or take any readings you want! Just let me know what I can do to help you help me
Thanks so much!