- Autopsy on a failed 50W LED floodlight - 1 Update
- dead USB drive anyone? - 7 Updates
- Mouser Electronics - 7 Updates
| N_Cook <diverse@tcp.co.uk>: Jun 23 09:08AM +0100 Chinese no-name YXY-FGD-50W White goo under the LED metal backing, only covering about 1/3 of the area, as originally placed blob , not fully splurged. Bowing of the metal at rear of the LED array , probably at original placement due to blob shape of the goo , only maybe worsened in use. So heatsinking via the periphery only , ie delayed heatsinking. |
| rickman <gnuarm@gmail.com>: Jun 22 03:48PM -0400 frank wrote on 6/22/2017 7:47 AM: > it separately, but I'm asking the expert here :) > Did anyone ever found a way to open (or otherwise read) these little > data killer devices? Just to be sure, you are talking about a USB Flash drive, right? I've yet to find one I couldn't open. It would cost them extra money to make them hard to open, solid plastic. Not sure what you might be able to fix inside other than a failed solder joint though. Mostly they are a single Flash chip with a built in controller, nothing to replace without losing the data in the chip. The lesson here is that Flash chips are not terribly reliable for long term storage. Anything on a Flash drive should be backed up on another Flash drive or your computer hard drive or both. Backup, backup, backup. -- Rick C |
| John-Del <ohger1s@gmail.com>: Jun 22 01:15PM -0700 On Thursday, June 22, 2017 at 3:48:13 PM UTC-4, rickman wrote: > Just to be sure, you are talking about a USB Flash drive, right? I've yet > to find one I couldn't open. It would cost them extra money to make them > hard to open, solid plastic. A good buddy of mine had some data and pictures on a flash drive that he could no longer read on his computer or any recovery software. So I opened it up looking for bad solder on the chip or a problem with the USB connector. Sure, the plastic outer case opened up easily enough but there was nothing inside. That's right, nothing.. Other than a two piece outer plastic case, the drive was a USB connector soldered to a multi-layer board with no external components on it. Whatever it used for a chip was embedded inside the PC layer. > The lesson here is that Flash chips are not terribly reliable for long term > storage. Anything on a Flash drive should be backed up on another Flash > drive or your computer hard drive or both. Backup, backup, backup. I have a library of .bin files for TV mainboards on 4 thumb drives as well as three PCs I own and several PC from others in the business. Too many years removing soldered-in eeproms and reading them to lose them to a balky flash drive. |
| rickman <gnuarm@gmail.com>: Jun 22 06:49PM -0400 John-Del wrote on 6/22/2017 4:15 PM: >> to find one I couldn't open. It would cost them extra money to make them >> hard to open, solid plastic. > A good buddy of mine had some data and pictures on a flash drive that he could no longer read on his computer or any recovery software. So I opened it up looking for bad solder on the chip or a problem with the USB connector. Sure, the plastic outer case opened up easily enough but there was nothing inside. That's right, nothing.. Other than a two piece outer plastic case, the drive was a USB connector soldered to a multi-layer board with no external components on it. Whatever it used for a chip was embedded inside the PC layer. Was there a black blob on the board? That would be epoxy covering the die mounted to the board. I see that on high volume, low cost products which only need one or two chips. Actually mounting chips inside the PCB is not something I've ever seen or heard of before. Not saying it's impossible, but it would be done for low cost and I don't think it would be any cheaper than the epoxy blob and in fact may be slightly more expensive. >> storage. Anything on a Flash drive should be backed up on another Flash >> drive or your computer hard drive or both. Backup, backup, backup. > I have a library of .bin files for TV mainboards on 4 thumb drives as well as three PCs I own and several PC from others in the business. Too many years removing soldered-in eeproms and reading them to lose them to a balky flash drive. Flash memory inherently wears out. It also has issues being made. To deal with both problems the chips are made with extra capacity and error correcting codes are used to find and correct errors. When a sector is found to have errors, the data is copied over to a spare block and the old one is marked as bad. The problem comes when there are too many errors to read the data on a failing block or when all the spare blocks are used. This makes SSD storage susceptible to sudden failure. -- Rick C |
| Michael Black <et472@ncf.ca>: Jun 22 07:38PM -0400 |
| John-Del <ohger1s@gmail.com>: Jun 22 07:45PM -0700 On Thursday, June 22, 2017 at 6:49:36 PM UTC-4, rickman wrote: > > A good buddy of mine had some data and pictures on a flash drive that he could no longer read on his computer or any recovery software. So I opened it up looking for bad solder on the chip or a problem with the USB connector. Sure, the plastic outer case opened up easily enough but there was nothing inside. That's right, nothing.. Other than a two piece outer plastic case, the drive was a USB connector soldered to a multi-layer board with no external components on it. Whatever it used for a chip was embedded inside the PC layer. > Was there a black blob on the board? That would be epoxy covering the die > mounted to the board. Absolutely not. I know what an IC printed on a PC and covered with epoxy looks like (most modern consumer electronics remotes have them). This was a multi layer board with no exposed lands save for the USB connections. The rest of the board was green mask with no place for any parts to be soldered to. If he still has it I'll take a pic and upload it. |
| stratus46@yahoo.com: Jun 22 08:53PM -0700 On Thursday, June 22, 2017 at 4:50:57 AM UTC-7, frank wrote: > data killer devices? > Thanks > Frank A couple of years ago a coworker had a flash drive from his daughter that had research material for her doctoral work and she was very upset. I plugged it into my machine and it was indeed dead. I flexed it a little and got the Windows beep for USB. She had flexed it in the side of the laptop while using it in bed and cracked the solder connection(s) in the drive. I just stressed it while it copied off the data to the hard drive and copied on to a new flash drive. I never found out if there was any damage to the laptop but she was very happy to get her data back. I think she learned a lesson about backups. If it's a 'portable' drive particularly with those wide USB 3.0 cables, I've seen those break too often but are easily available. G² |
| rickman <gnuarm@gmail.com>: Jun 23 12:50AM -0400 >> Frank > A couple of years ago a coworker had a flash drive from his daughter that had research material for her doctoral work and she was very upset. I plugged it into my machine and it was indeed dead. I flexed it a little and got the Windows beep for USB. She had flexed it in the side of the laptop while using it in bed and cracked the solder connection(s) in the drive. I just stressed it while it copied off the data to the hard drive and copied on to a new flash drive. I never found out if there was any damage to the laptop but she was very happy to get her data back. I think she learned a lesson about backups. > If it's a 'portable' drive particularly with those wide USB 3.0 cables, I've seen those break too often but are easily available. I'm no fan of the typical USB connection for flash drives in laptops. It is far too easy to damage both the drive and the PC. I often use a short USB extension cable for plugging in a flash stick. But that still leaves the laptop connector vulnerable as the typical USB connector still creates are pretty big lever arm. I don't even like the "micro" size mouse dongles. I had a laptop bag ripped from putting the laptop in it with the dongle installed. The tear ended up running and destroyed the whole bag. -- Rick C |
| Jeff Liebermann <jeffl@cruzio.com>: Jun 22 11:19AM -0700 On Thu, 22 Jun 2017 07:55:33 -0700 (PDT), "pfjw@aol.com" >in the past were about to be discontinued (as obsolete) >by the manufacturer. >Few suppliers bother with this level of service. It's fairly common practice among the various distributors. They expect you to panic at the thought of having to redesign your product for a different part. You then purchase a huge number of the soon to be obsolete parts, so that you're not stuck dealing with the greedy obsolete parts jobbers. In other words, the notice that the part is about to become discontinued is a very effective sales pitch. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| "pfjw@aol.com" <pfjw@aol.com>: Jun 22 11:35AM -0700 On Thursday, June 22, 2017 at 2:19:43 PM UTC-4, Jeff Liebermann wrote: In other words, the notice that the part is > about to become discontinued is a very effective sales pitch. Rick & Jeff: By any standard, I am a onsie-twosie buyer, so this sort of notice is of interest to me as indicative of a level-of-service. I might buy 200 capacitors of a common value, or diodes (1-3 year supply, but sure to be used) so as to reach price-points, but other than those few things, I usually purchase in 10-or-less amounts, and then most purchases are task-specific. Put another way, what I repair is personal, not-for-money, and not time-critical. Peter Wieck Melrose Park, PA |
| Andy Burns <usenet@andyburns.uk>: Jun 22 08:34PM +0100 > what I repair is personal, not-for-money, and not time-critical. Mouser's computer doesn't know that ... |
| rickman <gnuarm@gmail.com>: Jun 22 03:42PM -0400 Jeff Liebermann wrote on 6/22/2017 2:19 PM: > be obsolete parts, so that you're not stuck dealing with the greedy > obsolete parts jobbers. In other words, the notice that the part is > about to become discontinued is a very effective sales pitch. That is a bit of a cynical attitude. Would it be better for them to *not* tell you in advance so that you end up placing an order only to be told the parts are discontinued? Lattice did a rather unusual thing in that they set a last order data some 3 years before the last delivery date, so you could schedule deliveries well in advance. Arrow bought some 80,000 that I know of. I was still shipping units but on a very erratic, completely unpredictable schedule so I waited and monitored the inventory. By the time I needed parts the count had dropped to 78,000, so clearly they were not flying off the shelf. My orders ramped up so I called for a quote. I had so much money coming in I considered buying a significant supply of 5,000. They still would not give me a decent price in spite of the fact that these parts just were not selling. Good thing I waited. I found out the products that my designs were going in were being EOL'd at the end of the year. I would have been stuck with 5,000 pieces. Arrow still has 72,000 pieces so unlike last year, I am not the only one buying them. But they will be a decade selling them at the double and triple prices they are listed for now. -- Rick C |
| Chuck <chuck@mydeja.net>: Jun 22 04:02PM -0500 On Thu, 22 Jun 2017 07:55:33 -0700 (PDT), "pfjw@aol.com" >Few suppliers bother with this level of service. >Peter Wieck >Melrose Park, PA Great company. I've ordered regularly from them for 28 years without them making one mistake. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
| Michael Black <et472@ncf.ca>: Jun 22 07:35PM -0400 |
| ggherold@gmail.com: Jun 22 06:34PM -0700 > Few suppliers bother with this level of service. > Peter Wieck > Melrose Park, PA I've had better luck with digikey and EOL warnings. But I order more stuff from DK too. (Newark never.) George H. |
| You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com. |
No Response to "Digest for sci.electronics.repair@googlegroups.com - 15 updates in 3 topics"
Post a Comment