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bitrex <user@example.net>: Mar 14 01:02AM -0400 I have a Behringer rackmount EQ on my desk again, exhibiting intermittent distorted or no output, no meter movement, etc:   Example image:   <https://imgur.com/a/SCVFbGq>   Problem affects both channels, I've traced it down to what seems to be open/damaged dual-gang potentiometers, the big ones on the far right in the pic for "warmth" (i.e tube distortion/coloration) control.   Here's the relevant portion of the schematic, the dual gang Alps pots in question are labeled VR27A/B and VR28A/B:   <https://imgur.com/a/eFmo1Zq>   I have my own functional unit to compare against; when I test those pots on mine in-circuit with the control board unplugged and removed from the rest of the circuit, with the pots at center position, measuring from the ground lugs to the other pins I get various resistances in the kilohm range, 4k, 8k, etc.   When I do the same on the faulty unit I measure open circuit on everything. on the pots on _both_ channels.   An open-circuit pot failure on both channels seems unlikely but can't really see what else it could be, the TL074 op amps IC1 and IC2 tested good, all power supply and tube bias and plate voltages look OK with no signal, etc.   Anything else to test to be sure before I yank them out and replace? De-soldering and replacing this kind of PCB-mount pot from plated-thru holes is super-annoying...

"pfjw@aol.com" <peterwieck33@gmail.com>: Mar 14 04:14AM -0700 A common spike could take out both, certainly. Before going ahead and replacing the pots - can you determine a source for such a spike, or how it could have happened?   Could also be a manufacturing defect common to both sections.   Peter Wieck Melrose Park, PA

Fox's Mercantile <jdangus@att.net>: Mar 14 06:36AM -0500 > Could also be a manufacturing defect common to both sections.   Behringer is known as the "Pep Boys"of studio equipment.   -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

"pfjw@aol.com" <peterwieck33@gmail.com>: Mar 14 05:26AM -0700 > Behringer is known as the "Pep Boys"of studio equipment.   I would be more inclined to use "Harbor Freight" for comparison. Pep Boys does stock a great deal of OEM equipment, as well as the cheap stuff. Harbor Freight does not.   Peter Wieck Melrose Park, PA

N_Cook <diverse@tcp.co.uk>: Mar 14 12:26PM On 14/03/2019 05:02, bitrex wrote:   > Anything else to test to be sure before I yank them out and replace? > De-soldering and replacing this kind of PCB-mount pot from plated-thru > holes is super-annoying...   What happens if you solder 5K, say, across the o/c parts of all pots?

bitrex <user@example.net>: Mar 14 12:20PM -0400 > I would be more inclined to use "Harbor Freight" for comparison. Pep Boys does stock a great deal of OEM equipment, as well as the cheap stuff. Harbor Freight does not.   > Peter Wieck > Melrose Park, PA   Eh, I think they get ragged on unfairly sometimes. It's not an otherwise cheaply made box, the enclosure is solid heavy steel enclosure, massive toroidal power transformer, linear power supply with conservatively-rated parts, the pots are Alps, the soldering-work looks great (compared to some truly awful crap I've seen from China.) It's essentially a solid-state EQ with a over-drivable tube exciter stage prior to it going into the four parametric bands I think it sounds quite nice strapped across the output of a mixer with some bass and treble boost and the "honky" mid-range cut a bit before going into a PC's ADC for recording lil jam sessions.   They're all pushing 20 years old tho stuff just breaks sometimes.   The most reliable piece of studio gear I have probably is my Behringer MX602 line mixer, running most every day for 19 years and all it's needed so far is a replacement headphone volume pot

Adrian Caspersz <email@here.invalid>: Mar 13 05:00PM On 13/03/2019 12:43, pfjw@aol.com wrote: that is, do not transport it openly in the family minivan.   > Bottom line: A proverbial ounce of caution beats the hell out of a pound of care. Common sense, rubber gloves, a breathing mask, Lysol, Bleach, Moth-balls, Insecticides (which often do not work on Spiders or Ticks, so read the label), and other elementary precautions conscientiously and carefully applied will "safen" even the nastiest of wild radios.   Beryllium dust, Hydrofluoric acid, Snakes, Radium Paint, Polychlorinated biphenyls, Lead, brominated flame retardants, Cadmium, Mercury, hexavalent chromium, Cyanide, Polyvinyl chloride, Methyl ethyl ketone peroxide ...   To be on the safe side, a Hazmat suit for ya electronics work?   -- Adrian C

John-Del <ohger1s@gmail.com>: Mar 13 10:45AM -0700 On Wednesday, March 13, 2019 at 1:00:07 PM UTC-4, Adrian Caspersz wrote:   > To be on the safe side, a Hazmat suit for ya electronics work?   > -- > Adrian C   I sprinkle at least a few of those on my Corn Flakes in the morning..

N_Cook <diverse@tcp.co.uk>: Mar 13 06:29PM On 13/03/2019 17:45, John-Del wrote:   >> -- >> Adrian C   > I sprinkle at least a few of those on my Corn Flakes in the morning..   That's called hormesis, a little bit of what does you harm, does you good.

N_Cook <diverse@tcp.co.uk>: Mar 13 01:59PM > Bottom line: A proverbial ounce of caution beats the hell out of a pound of care. Common sense, rubber gloves, a breathing mask, Lysol, Bleach, Moth-balls, Insecticides (which often do not work on Spiders or Ticks, so read the label), and other elementary precautions conscientiously and carefully applied will "safen" even the nastiest of wild radios.   > Peter Wieck > Melrose Park, PA   And the perennial one, electrocution. The first time for me, in the UK so 240V. Aged perhaps 6 or 8 years old, I decided to unscrew the bakelite hemisphere of the dangling light switch. I assume it was off, but presumably learnt the hard way, that if something is off , then its not necessarily safe. Second time was as an electronics student, in same house as another electronics student. We decided to have a party in the derelict house next door, much better condition than our rented student house. Surviving ring main there, so a matter of connecting a lead between the 2 houses. Prearranged a string between the upper windows. Come the evening other electronics student tied the string to a lead with a plug on either end. He grabbed the live plug as he'd already plugged in the other end and got a shock. Then he tugged the string , so I could pull through , and of course the first thing I did was grab the live plug. So beware the stupidity of others . We both survived that and other electric shocks , to this day surprisingly.

Tim R <timothy42b@aol.com>: Mar 13 01:27PM -0700 On Wednesday, March 13, 2019 at 9:59:35 AM UTC-4, N_Cook wrote: > So beware the stupidity of others . We both survived that and other > electric shocks , to this day surprisingly.   Don't forget hurricane season is upon us. I don't know how people survive connecting a generator with those suicide cords, but they look like a Darwin award waiting to happen.

Peter Jason <pj@jostle.com>: Mar 14 07:38AM +1100 On Wed, 13 Mar 2019 05:43:22 -0700 (PDT),   >Although not many here are scroungers or scavengers, perhaps there are enough to merit this post. I have pulled any number of gems out of dumpsters, barn sales and yard sales, in any case. This applies mostly to the continental United States, but I am sure similar perils lurk everywhere. So:   Fructose & corn syrup. Fucks the liver, induces obesity, kills more people than the bugs.

John Robertson <spam@flippers.com>: Mar 13 03:17PM -0700 > Bottom line: A proverbial ounce of caution beats the hell out of a pound of care. Common sense, rubber gloves, a breathing mask, Lysol, Bleach, Moth-balls, Insecticides (which often do not work on Spiders or Ticks, so read the label), and other elementary precautions conscientiously and carefully applied will "safen" even the nastiest of wild radios.   > Peter Wieck > Melrose Park, PA   Thanks Peter, that is a good reminder! I have forwarded it to my shop manager for his annual review with staff. We get games in from all over the world and they haven't all been stored well.   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

tabbypurr@gmail.com: Mar 14 02:25AM -0700 > Another demonstration that Common Sense isn't.   > Peter Wieck > Melrose Park, PA   Up-pointing nails often go through ordinary shoes & boots well enough. Anyone scavenging anything ought to know that.     NT

tabbypurr@gmail.com: Mar 14 02:26AM -0700 On Wednesday, 13 March 2019 13:59:35 UTC, N_Cook wrote:   > presumably learnt the hard way, that if something is off , then its not > necessarily safe. > Second time was as an electronics student, in same house as another   so you must be writing from beyond the grave

"pfjw@aol.com" <peterwieck33@gmail.com>: Mar 14 04:17AM -0700 > > Melrose Park, PA   > Up-pointing nails often go through ordinary shoes & boots well enough. Anyone scavenging anything ought to know that.   > NT   Tabby:   I, too, can describe any of dozens of catastrophic conditions combined with a fundamental lack of common sense that will give bad results. Such a list would run to the point where eyes start to glaze over, and the basic message will be lost.   The basic message is: Be Careful. Be Aware.   Peter Wieck Melrose Park, PA

"pfjw@aol.com" <peterwieck33@gmail.com>: Mar 14 04:19AM -0700 On Wednesday, March 13, 2019 at 4:38:17 PM UTC-4, Peter Jason wrote:   > Fructose & corn syrup. > Fucks the liver, induces obesity, kills more > people than the bugs.   Its all sugar, and in moderation, no worse than starch, alcohol, apples, oranges, cherries and cantaloupe.   Peter Wieck Melrose Park, PA

N_Cook <diverse@tcp.co.uk>: Mar 14 11:04AM TO18 size of can but inerference fit? mounted in a brass mount with lens, no type number seen. Actively passing 60mA drops 1.3V and DVM-D test shows 1V one way, so diode function , but no IR out as tested with IR zapper tester of IR photodiode in series with optical LED , indicates on or flashing of any working zappers ever tried with it. So are they known to fail optically, perhaps overdriven, but not go o/c or low ohms , still functioning as a diode though. ? Kit specs say 910nm and no tab seen , but TO-18 can type , although that could be machined off to clear the brass barrel , any machining not seen as axial view only, due to the surrounding brass barrel. So something like SFH400 to 2, FPE500 to 530, OP223,224,231,232,233, or TIL23 to 25 but none of those are specified as exactly 910nm , ranging 880 to 950nm. Initially I will try heating the assembly to 120 deg C and blast of freezer spray to TO18 package , to try breaking presumed assembly-heated interference fit , to split apart. Other than finally drilling out or seriously heating if laquer fit, any ideas to break apart without destroying any marking. Hand scratched on the brass is number 3738 presumably relating to a test of the lens combination or perhaps coding of date in 1978 , as 1979 kit.

Tim R <timothy42b@aol.com>: Mar 13 05:42PM -0700 Less than a month ago (Feb 20th) I put 3 bulbs from a 4 pack of GE 60 w equivalent dimmable LED bulbs in a ceiling fixture in the bathroom. Two are dead now. I've tried them in other fixtures and they don't work; I've tried other bulbs in the bathroom and those do work.   The weird thing is the symptom. Screwing them in and out, occasionally they will flash on, as if a connection was making briefly. This is true in multiple sockets.   They have a 5 year warranty, but must provide the proof of purchase, which nobody saves, and mail to GE at my cost. Pretty safe warranty risk I'd say. The box says 13 year life. I got about 3 weeks out of these.

Tom Biasi <tombiasi@optonline.net>: Mar 13 08:54PM -0400 On 3/13/2019 8:42 PM, Tim R wrote: > Less than a month ago (Feb 20th) I put 3 bulbs from a 4 pack of GE 60 w equivalent dimmable LED bulbs in a ceiling fixture in the bathroom. Two are dead now. I've tried them in other fixtures and they don't work; I've tried other bulbs in the bathroom and those do work.   > The weird thing is the symptom. Screwing them in and out, occasionally they will flash on, as if a connection was making briefly. This is true in multiple sockets.   > They have a 5 year warranty, but must provide the proof of purchase, which nobody saves, and mail to GE at my cost. Pretty safe warranty risk I'd say. The box says 13 year life. I got about 3 weeks out of these.   Happens quite often with cheap LEDs.

"jfeng@my-deja.com" <jfeng@my-deja.com>: Mar 13 08:24PM -0700 I think this was in Electronics Design: The solder joints for the LEDs were a vulnerable point, and they attributed it to insufficient heat sinking. The lifetime was maximized in the bulb up position and minimized when the bulb was down, presumably due to the difference in the convection. The apparent amount of heat sinking varied from brand to brand.   You can test this hypothesis by opening the dead bulb (voiding your warranty) and applying power to each of the LEDs individually. I think you need 10-12V for each LED.

John Robertson <spam@flippers.com>: Mar 13 10:30PM -0700 On 2019/03/13 5:42 p.m., Tim R wrote: > Less than a month ago (Feb 20th) I put 3 bulbs from a 4 pack of GE 60 w equivalent dimmable LED bulbs in a ceiling fixture in the bathroom. Two are dead now. I've tried them in other fixtures and they don't work; I've tried other bulbs in the bathroom and those do work.   > The weird thing is the symptom. Screwing them in and out, occasionally they will flash on, as if a connection was making briefly. This is true in multiple sockets.   > They have a 5 year warranty, but must provide the proof of purchase, which nobody saves, and mail to GE at my cost. Pretty safe warranty risk I'd say.. The box says 13 year life. I got about 3 weeks out of these.   I have run into a similar failure mode on other 'dimmable' LEDs. A few we bought from Home Depot stopped dimming or even turning on IF they were installed in acircuit with and LED rated dimmer. Sometimes they would flash on. If they went into a similar fixture without the dimming (direct wall switch) then they work just fine.   Nothing wrong with the LED, it runs on the bench power supply. The circuit is cUL approved, so is not a really cheap knock-off. I'm assuming the power supply is at fault, but haven't traced the circuit to see where the failure points are. The primary filter cap charges up just fine though.   If you bought them at a big box store they should take them back and probably have your transaction record on file. If you bought on line then you are likely out of luck unless you can dig out the receipt from emails and credit card statement.   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

bitrex <user@example.net>: Mar 14 02:06AM -0400 On 03/13/2019 08:42 PM, Tim R wrote: > Less than a month ago (Feb 20th) I put 3 bulbs from a 4 pack of GE 60 w equivalent dimmable LED bulbs in a ceiling fixture in the bathroom. Two are dead now. I've tried them in other fixtures and they don't work; I've tried other bulbs in the bathroom and those do work.   > The weird thing is the symptom. Screwing them in and out, occasionally they will flash on, as if a connection was making briefly. This is true in multiple sockets.   > They have a 5 year warranty, but must provide the proof of purchase, which nobody saves, and mail to GE at my cost. Pretty safe warranty risk I'd say. The box says 13 year life. I got about 3 weeks out of these.   There's a large indoor mall down the road from me that was quite the happenin' spot in the 1990s, but like so many malls in the US post-Amazon is still hanging on but has seen better days.   At some point they replaced all the accent lighting on the support pillars on the right and left of this image with LED bulbs but they cheeped out and now about 500 of 'em are busted or flickering making the whole place look like a seedy German discotheque. No funds to pay anyone to replace 'em. Oh well.   <https://imgur.com/a/U5jWgpO>

Lucifer <LuciferMorningstar@bigpond.com>: Mar 14 05:24PM +1100 >> which nobody saves, and mail to GE at my cost. Pretty safe warranty >> risk I'd say. The box says 13 year life. I got about 3 weeks out of >> these.   The Chinese made 5 watt LED lamp in my bedroom stopped working, then it started working again.   >cheeped out and now about 500 of 'em are busted or flickering making the >whole place look like a seedy German discotheque. No funds to pay anyone >to replace 'em. Oh well.   Need to place someone on light duties.

tabbypurr@gmail.com: Mar 14 02:29AM -0700 On Thursday, 14 March 2019 00:42:41 UTC, Tim R wrote: > Less than a month ago (Feb 20th) I put 3 bulbs from a 4 pack of GE 60 w equivalent dimmable LED bulbs in a ceiling fixture in the bathroom. Two are dead now. I've tried them in other fixtures and they don't work; I've tried other bulbs in the bathroom and those do work.   > The weird thing is the symptom. Screwing them in and out, occasionally they will flash on, as if a connection was making briefly. This is true in multiple sockets.   > They have a 5 year warranty, but must provide the proof of purchase, which nobody saves, and mail to GE at my cost. Pretty safe warranty risk I'd say. The box says 13 year life. I got about 3 weeks out of these.   Common problem. Opening them may reveal a faulty LED or melted/oxidised solder joint. Or less likely something else.     NT

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