Showing posts from June, 2018

Lg Stylo 4: a disappointing "upgrade'

I've been saying a lot of positive things about the Stylo 3, and had high hopes for the 4th edition. Sadly LG is not the only one not reading my blog ;-)
Most disappointing is that the Stylo 4 does not have a removable back. No longer can you replace they battery. Or other broken components (which I have actually done on my Stylo 3). In this day and age there isn't such a huge improvement in phones every year. Continuing to make them disposable instead of repairable is morally questionable, and I thought that at least the the Stylo team had this figured out. The Stylo 3 was trivially easy to disassemble, and replacing a broken LCD took 10 minutes. No longer with the Stylo 4, which has a glued on back just all the other phone of this era.

Testing a generic 128gb microSD card: it's junk!

I purchased a 128GB SD card from ebay, for $10. At this price it pretty much had to be a lower capacity card that's been programmed to report greater capacity than it really has. Given how good ebay's buyer protection is I was curious to see how one of these preformed. Man, it's junk.

Delivery was quick, just 3 days. The package is so generic it doesn't even have a capacity printed on it. You have to look at the microSD card itself for that, which as advertised on ebay says 128GB.  No speed listing or anything but I will say it was a very easy to open package. So in that one way only, it was superior to what you would get in the store.

Windows recognized it as having 125GB of space, A somewhat odd compromise between marketing GB (1GB=1000^3) and real GB (1GB = 1024^3). FYI  a real SD card marketed as 128gb has 119 real GB. Since we don't expect it to have all that space anyway, who cares. So I tried writing just 1GB to it. Write speed quickly dropped to 1MB/s, and then  failed completely at about 400MB!  I had to reinsert the card to get windows to see it. Interestingly, it now claims to have a 55 GB file on (I've heard of hardware that employes file compression but never file expansion!).

Unsurprisingly, the 400MB that did get written were highly corrupted. I got tired waiting to see how much was actually good, since read speed was just 65KB/s! I mean, what is that? Class .0001? After reading 280MB, only 60mb of the data "written" was stored.

I tried the same trick I  used with my other fake SD card and added a dummy 500mb partition to the start of the disk so that the real file system would start at a later, perhaps better functioning region of flash memory. But that failed even worse, with only 80MB "written" before the drive became inaccessible.

So in conclusion, this generic SD card is complete junk. I paid $10 for "128"GB, but got perhaps .06GB. At that price ratio, a full 128gb would cost $2000! So that's a pretty bad deal. Of course, I asked for a refund, but even at $0, .06GB isn't worth anything.

Testing a fake 128GB Samsung EVO+ micro SD card

For about $45 you can buy a Samsung 128GB Micro SD card from Amazon. Sellers on Ebay offer them new for a lot less. I selected one for $26, shipped (from S. California), suspect it would be a fake, but curious what I would get. What I got looked reasonably real (shown here after opening).

My phone and laptop both reported full 128GB of space. Interestingly, the case contained the regular disclaimer that 1GB = 1000,000,000 bytes, but presumably in an attempt to avoid suspicion the card reported a full 128GB of space (using 1024^3 = 1GB). I tested it by copying some files to it and immediately had problems. The transfer rate was abysmal, between 1 and 2 MB/s, nothing close to the advertised rate on the package. And Windows kept on saying the card wasn't inserted, or needed to be checked for errors. After checking for errors some of the files were missing. I figured maybe the first part of the disk was bad, corrupting the FAT file system data, so I partitioned the disk in two, starting with a dummy 8mb partition.

The dummy partition helped. The write speed of the disk went up to about 5MB/s and Windows stopped reporting damage to the file system.

I also got more systematic and used a tool called H2testw to verify the actual storage space on the card. h2testw is not the nicest tool, but it got the job done, revealing that a full 24gb of "usable" space on the disk. Well, sort of usable: even keeping within that fraction of space, some of the data written was corrupted, though well below 1%.  So the card had about 20% of the advertised 128gb, which is a pretty bad deal for $26, especially given the random corruption of that 24gb (undetected until read back). For comparison, Amazon currently sells real 32GB Samsung cards for $16, or 50 cents/GB, whereas this card cost about 100 cents/GB.

I suppose I could use it to store my MP3 collection for playing back on a old phone. Time will tell if the usable storage remains usable long enough to make even that worthwhile.

Final note: that SD card adapter was so cheap that it failed after just a couple insertion/removal cycles. See the crack in the lower left corner. Thus, all my tests were conducted with a genuine Samsung adapter.

Repairing Win7 autochk "Cannot open volume for direct Access" error after power loss

My Win7 PC recently lost power while it was doing heavy work (compiling my latest android app). The result was file system corruption that could not be fixed the normal way (by scheduling to run chkdsk during bootup).  Here's the very useful error message Win7 gave me:

Checking file system on C:
Cannot open volume for direct access
Autochk cannot run due to an error caused by a recently installed software package.  Use system restore....
An unspecified error occurred (766f6c756d652e63 3f1)

I doubt a power failure really counts as installing a software package, MicroSoft.

What's going on here is unclear, but the problem persists; no amount of rebooting and running chkdsk at bootup fixes it, you always get this message. Nor could I run chkdsk while the OS is fully loaded (since it's my C drive).

But there is a solution, it seems. Reboot into system repair mode (F8 during boot up), and then select the command prompt. Find you C drive (it almost certainly won't be labeled as C; in my case it was H), and run chkdsk /r on it. For some reason it does not let the file system corruption prevent the scan here. The process is slow: on my mostly full 110GB SSD drive (samsung 840), it took a good 30 minutes. But it found and fixed the errors and now my PC can boot properly. Somewhat oddly the scan concluded with "Failure to transfer logged messages to the event log with status 50." but this seems to be non-fatal. 

Sony PSone power supply 7.5v 2a scph-113 disassembly and failed repair

Didn't work & I thought maybe the plug flip mechanism was the cause since there was no conductivity between the prongs and the DC tip. Breaking it open meant breaking glue so it wouldn't have been a pretty fix even if it worked. But it didn't - on the inside it was possible to measure continuity between the prongs and the circuit board. And no caps were visually failing, so I gave up :-(

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