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harry newton <harry@is.invalid>: Dec 27 03:28PM Talk about drastic!   Apple throttled your iPhone by cutting its speed almost in HALF!   "After replacing the battery, Geekbench showed that the scores had nearly doubled."   <http://nymag.com/selectall/2017/12/is-apple-slowing-down-iphones-with-aging-batteries.html>

"David Farber" <farberbear.unspam@aol.com>: Dec 26 02:16PM -0800 I'm servicing a Behringer EUROPOWER PMH2000. The + and - 15 volt regulators need replacing because the leads have failed. The transistor is mounted to the chassis at a 90 degree angle and then soldered to the pc board. The problem is that pc board fits very tightly into the chassis. The leads on the regulators keep getting flexed with each pc board removal. Anyway, I want to replace them because a couple of the leads have broken off. They are packaged in a TO-220 case. The center tab is nonmetallic so it is insulated from the chassis. Though the schematic says terminal 2 is grounded in the 7815A anyway, I was wondering if it made any difference whether or not I purchased ones with metallic backing or ones with a plastic backing.   I just looked at the LM7915 spec sheet and it says that terminal 1 is ground and terminal 2 is the input which is reversed from the positive regulator. It also doesn't mention whether or not it has a metal tab, which if it did, would have to be insulated from the chassis. Do any of you have any experience replacing these regulators in a chassis mount situation?   Thanks for your reply. -- David Farber Los Osos, CA

whit3rd <whit3rd@gmail.com>: Dec 26 04:56PM -0800 On Tuesday, December 26, 2017 at 2:16:52 PM UTC-8, David Farber wrote: > want to replace them because a couple of the leads have broken off. They are > packaged in a TO-220 case. The center tab is nonmetallic so it is insulated > from the chassis.   I presume, however, that the tab connects to the chassis for heatsinking?   Best practice if the strain on the component is breaking wires, is to use a strain-relieved wiring connection, like a few-inches pigtail wiring from the regulator to a female Molex KK socket; this will plug onto male pins mounted in the printed wiring board, 0.100" centers spacing just like the LM78xx.   Those regulators are available in fullpak (epoxy insulated tab), metal-tab-wth-hole, and short-metal-tab (for soldering to a surface mount "heatsink").

Phil Allison <pallison49@gmail.com>: Dec 26 11:42PM -0800 David Farber wrote:   ---------------------- > want to replace them because a couple of the leads have broken off. They are > packaged in a TO-220 case. The center tab is nonmetallic so it is insulated > from the chassis.   ** The *mounting tab* is definitely metal, just coated in epoxy to insulate it.     > It also doesn't mention whether or not it has a metal tab, which if it did, > would have to be insulated from the chassis. Do any of you have any > experience replacing these regulators in a chassis mount situation?   ** If the originals are held on with a clamp, you need to buy the same again.   If held with 3mm bolts, you can use the ones you have.   BUT you MUST add insulating bushes and mica pads to BOTH - plus a smear of white thermal grease.   Bolting the positive one straight to the chassis is likely to result in ground loop hum.     ... Phil

Jeff Liebermann <jeffl@cruzio.com>: Dec 26 09:04AM -0800 >Thanks for the help. This is an outdoor display, but I use it indoors.   To the best of my limited knowledge, indoor and outdoor Hannukah lights are the same.   Incidentally, look for the UL 588 label: <https://industries.ul.com/wire-and-cable/seasonal-lighting>   >So no animals have chewed on the wires.   Assumption, the mother of all screwups. Just inspect the wiring and see if there's any damage. You got used which means it could have been abused in a multitude of ways.   >I dont hasve whole sections out, >just two or three bulbs that dont light.   It could be a parallel wired affair with built in current limiting resistors as mentioned in the patent: <https://www.google.com/patents/US8007129>   >I could just leave it alone, >but if it's series wired, I know it will eventually overload other >bulbs.   Look at the way series arrays are wired. There's no way to overload them, unless you're into shorting out the LED's that died.   >(Yea, I need to get a better look at the way it's wired).   You need to get a better look at the way it's wired. You need to get a better look at the way it's wired. You need to get a better look at the way it's wired. You need to get a better look at the way it's wired. I thought it would help if I repeated that a few extra times.   >Plus >this was a very costly and very pretty display, so I want to keep it in >tip-top shape. (Which is why I only use it indoors).   Costly or overpriced?   >The reason I got this, was because it was a store display, and I got it >at a much reduced price.   Yes, but you're suppose to do that AFTER the holidays, when the stores unload all their holiday paraphernalia. Are you sure you got a good price, or did the store just unload something broken which they couldn't sell?   >So, running it in the store for weeks probably >killed the weak LEDs.   Unless overheated or run a unusually high current, LED's should last thousands of hours. You're thinking of the bad old days of incandescent lights, where replacing bulbs was a regular exercise.   Before you replace any LED's, You need to get a better look at the way it's wired and determine if there's an internal ohmsistor or current limiter. Replacing one of those with an ordinary LED is going to produce a very bright flash before the fuse blows.   >However there was no box or instructions.   If anything were included in the box, it would be a wholesale repudiation of responsibility and various legal disclaimers in a dozen foreign languages.   I originally suspected that if I did the research, I would find that there are a few giant factories in China making both the quality and the junk lights, which are then packaged, private labeled, distributed, and sold by a multitude of disreputable vendors. Well, more than a multitude. This list shows 863 manufacturers: <http://www.made-in-china.com/products-search/hot-china-products/Tree_Light.html> and 535,000 vendors in China: <https://www.alibaba.com/countrysearch/CN/christmas-light.html> Identifying your lights may be difficult.   >I'm sure >it was NOT made in the US, so finding the manufacturer is not gonna help >determine the proper bulbs.   There are no Hanukah light manufacturers left in the USA. <https://www.christmasdesigners.com/blog/made-in-usa-christmas-lights/>   -- 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

tabbypurr@gmail.com: Dec 26 09:46AM -0800 On Tuesday, 26 December 2017 17:04:57 UTC, Jeff Liebermann wrote: > On Tue, 26 Dec 2017 05:08:41 -0600, oldschool@tubes.com wrote: 8<   > >So, running it in the store for weeks probably > >killed the weak LEDs.   unlikely   > and determine if there's an internal ohmsistor or current limiter. > Replacing one of those with an ordinary LED is going to produce a very > bright flash before the fuse blows.   Quicker to just replace & see if they work. If the new LEDs light and the old don't, then different limited LEDs needed.     NT

Jeff Liebermann <jeffl@cruzio.com>: Dec 26 11:01AM -0800 >Quicker to just replace & see if they work. If the new LEDs >light and the old don't, then different limited LEDs needed. >NT   I was wondering what the white stuff that falls out of the sky around this time of year might be. Initially, I thought it might be snow, but after considering your suggestion, I suspect it might be the fallout from exploding white LED's that were tested using your methodology.     -- 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

tabbypurr@gmail.com: Dec 26 01:59PM -0800 On Tuesday, 26 December 2017 19:01:41 UTC, Jeff Liebermann wrote: > but after considering your suggestion, I suspect it might be the > fallout from exploding white LED's that were tested using your > methodology.   Lol. I doubt it. The OP hasn't a clue what he's got, the possibility of killing a 1 cent LED by overcurrent is no big deal.     NT

bitrex <bitrex@de.lete.earthlink.net>: Dec 26 09:18PM -0500 On 12/26/2017 08:16 AM, Fox's Mercantile wrote: >> is not gonna help determine the proper bulbs.   > Ya know, for someone who is constantly pissing and moaning about > "Unreliable Chinese shit" you sure seem to buy a lot of it.   Like politicians who want to ban porn because they've "done the research" on how awful it all is. Ah, ok, definitely tell me all about it then Mr. Expert

oldschool@tubes.com: Dec 26 06:44PM -0600 On Fri, 22 Dec 2017 18:04:44 -0500, "Percival P. Cassidy" >never totally extinguish but only dim to a a faint glow.   >Any way of using both the illuminated switch and the 40W LEDs?   >Perce   Are you using dimmable or non-dimmable LED bulbs?   That may make a difference.... (just a thought).

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