USB connection really flaky

Discussion about the new DM41X calculator
Dave Britten
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USB connection really flaky

Post by Dave Britten » Tue Oct 13, 2020 9:40 pm

Anybody else having a problem with this? I usually need multiple attempts to get it to connect in USB disk mode, and it sometimes doesn't stay connected. I tried copying over a couple modules, it froze mid copy, the calculator wouldn't respond to anything but the Reset button on the back, and now the entire FAT filesystem is completely corrupt. :/

dlachieze
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Re: USB connection really flaky

Post by dlachieze » Tue Oct 13, 2020 10:21 pm

This thread could be relevant for you depending on your USB cable plug.
DM42: 00425 - DM41X: β00066

Dave Britten
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Re: USB connection really flaky

Post by Dave Britten » Tue Oct 13, 2020 11:33 pm

Yeah, I think that's probably the issue. Seems like SM ought to look at moving the USB port to the side where the case is nice and flat and the port can sit more flush. And also fix the USB disk mode so that it doesn't completely lock up during a failed transfer or unexpected disconnect, forcing a press of the Reset button.

I'm off to see if I can find any good micro USB cables with low-profile collars, and grumble some more about losing the programs in RAM that I was writing...

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salvomic
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Re: USB connection really flaky

Post by salvomic » Tue Oct 13, 2020 11:42 pm

about Disk lock up:
in my new DM41X I have had two disconnections this evening; in the first the calc hanged and I had to reset, the disk was damaged and I had to format. So I did a backup.
In the second I made the reset but I could recover the state and the disk was ok, also if the Offing folder was apparently damaged, and I replaced it with that on the backup.
My cable is tiny and apparently has no "plastic problems" but I don't know why those disconnections in my MacBook (I use the same cable with DM42 and luckily I hadn't this problem). Maybe is could be the connector or a software random problem...

I noted inside the Disk of DM41X a folder "Backups": is it for the system or the user could use it (how?).
However, I made a whole backup copying all in a folder in the computer.

Salvo
∫aL√0mic (IT9CLU) :: DM42 (SN: 00881), DM41X (SN 00523), DM16, HP Prime, 50g, 41CX, 42s, 71b, 15C, 12C, 35s, WP34s -- Free42

rprosperi
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Re: USB connection really flaky

Post by rprosperi » Wed Oct 14, 2020 12:48 am

salvomic wrote:
Tue Oct 13, 2020 11:42 pm

I noted inside the Disk of DM41X a folder "Backups": is it for the system or the user could use it (how?).
However, I made a whole backup copying all in a folder in the computer.
Always look in the manual regarding how to use a built-in feature. In this case, look here:

https://technical.swissmicros.com/dm41x ... ull_backup

We worked hard and believe all 41X-unique features are documented in the manual.
--bob p

DM42: β00071 & 00282, DM41X: β00071, DM10L: 071/100

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salvomic
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Re: USB connection really flaky

Post by salvomic » Wed Oct 14, 2020 10:28 am

rprosperi wrote:
Wed Oct 14, 2020 12:48 am

Always look in the manual regarding how to use a built-in feature. In this case, look here:

https://technical.swissmicros.com/dm41x ... ull_backup

We worked hard and believe all 41X-unique features are documented in the manual.
you are right!
in this moment I'm a bit "more" abstentions-minded, so I tell myself: RTFM :)
Thanks SwissMicros for the great effort to give us these jewels!

Salvo
∫aL√0mic (IT9CLU) :: DM42 (SN: 00881), DM41X (SN 00523), DM16, HP Prime, 50g, 41CX, 42s, 71b, 15C, 12C, 35s, WP34s -- Free42

HPMike
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Re: USB connection really flaky

Post by HPMike » Thu Oct 15, 2020 3:24 am

Tonight I had a sudden disconnect from my pc that froze the calculator, and when I reconnected after reset, the files in the OFFIMG folder were gone, but otherwise the FAT disk seemed ok. The pc connected briefly the first time, then suddenly disconnected with message that it didn't recognize my device. My cable connection is very tight, and the cable is high quality (it's actually the cable that came with my HP Prime), so I don't think that has anything to do with this problem. I was connecting to re-flash my firmware back to the production level version, after downgrading to the last beta version to attempt to root cause a problem I was having saving program raw files to the FAT disk, and the beta version won't read the renamed production help file. Anyway, there have been a slew of issues with my unit, this being the latest.
DM15L, S/N 00548. DM42, SN: 00159. DM41X, SN: 00973.

Thomas_ER
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Re: USB connection really flaky

Post by Thomas_ER » Thu Oct 15, 2020 7:38 am

HPMike wrote:
Thu Oct 15, 2020 3:24 am
... My cable connection is very tight, and the cable is high quality (it's actually the cable that came with my HP Prime), ...
Hello Mike, some USB plugs (or their plastic housings) are a little too big for the DM42 (and the DM41X), maybe resulting in a unstable connection.
I helped myself with a little cosmetic change to the connector with a sharp knife. No electrical parts are changed. See the photos.
(Maybe that affects your other problem as well.)
Attachments
201015_USB_Plug_a.jpg
201015_USB_Plug_a.jpg (38.43 KiB) Viewed 358 times
201015_USB_Plug_b.jpg
201015_USB_Plug_b.jpg (40.49 KiB) Viewed 358 times
[ HP48/49/50/42S/WP34/HP Prime/ DM42 (#00185+00318) ]

HPMike
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Re: USB connection really flaky

Post by HPMike » Thu Oct 15, 2020 3:05 pm

Thomas_ER wrote:
Thu Oct 15, 2020 7:38 am
HPMike wrote:
Thu Oct 15, 2020 3:24 am
... My cable connection is very tight, and the cable is high quality (it's actually the cable that came with my HP Prime), ...
Hello Mike, some USB plugs (or their plastic housings) are a little too big for the DM42 (and the DM41X), maybe resulting in a unstable connection.
I helped myself with a little cosmetic change to the connector with a sharp knife. No electrical parts are changed. See the photos.
(Maybe that affects your other problem as well.)
Hello Thomas, I’ve aleady modified my cable head as you describe, and the connector is fully inserted into the USB port on my DM41X. I learned this long ago when I purchased my DM42, and experienced this problem.
DM15L, S/N 00548. DM42, SN: 00159. DM41X, SN: 00973.

Dave Britten
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Joined: Wed Jun 14, 2017 9:27 pm

Re: USB connection really flaky

Post by Dave Britten » Thu Oct 15, 2020 4:26 pm

I ended up butchering a USB cable like the photos, but on all four sides, and it goes completely into the socket now. My DM42 never needed such barbaric cable modifications, so I wasn't expecting different from the DM41X (the port is actually better aligned in the case opening than the DM42). Seems like it's working reliably enough this way.

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