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Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Mar 21 04:11AM +1100 On 20/03/2017 11:58 AM, Phil Allison wrote:   > ** I have already pointed out that Sydney's biggest spare parts > dealer( WES components) has the BF470 in stock for under $1.   > Sylvia lives in Sydney.   **I am VERY wary about buying anything from WES now. From their shitty electrolytic caps (Jamicon - horrible things, one batch of 100 I purchased had a 30% failure rate - I had to recall half a dozen units I serviced as a precaution) to counterfeit semiconductors, I've been caught several times. As have some of my colleagues. I readily admit that small, cheap devices are likely to be fine though. I purchased some large, Japanese flatpack (two screw mounting types) from WES last year. Same type as the ones in the amp. It failed during bench testing. Subsequent tests on replacement devices revealed a breakdown Voltage (VCEO) of around 90 Volts. The original devices are specc'd at 230 Volts. I ended up using single screw mounted devices (same ratings), obtained from an accredited supplier. No problems. A mate did battle with a TV set flyback MOSFET a few years back. After many hours chasing his tail, I suggested he stop buying WES supplied parts and go to Element14 for the MOSFET (less than $5.00). Problem solved. WES were kind enough to refund his money for the dodgy MOSFETs, but not the considerable amount of wasted time.   Never again. All my electros are sourced from Element14 or RS Components. Panasonic is my favourite brand. Phenomenally low failure rate and well priced. That free delivery from RS is very nice. My spend with WES has fallen dramatically.     -- Trevor Wilson www.rageaudio.com.au

ohger1s@gmail.com: Mar 20 10:39AM -0700 On Monday, March 20, 2017 at 1:18:00 PM UTC-4, Trevor Wilson wrote:   > -- > Trevor Wilson > www.rageaudio.com.au   I learned the hard way about counterfeit semis decades ago. Home stereo amps that would blow up in a week after repair, horiz/HV output transistors shorting on power up, hybrid smps ICs that just didn't work or would cause severe oscillation, vertical output ICs running hot and failing in days, PTV convergence hybrid modules that defied alignment...   Here in the U.S., the only suppliers I trust are DigiKey, Mouser, and B&D Enterprises. I'm sometimes forced to buy parts through AliExpress. These are carefully tested. If one is bad, the batch gets scrapped.

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Mar 21 05:36AM +1100 > B&D Enterprises. I'm sometimes forced to buy parts through > AliExpress. These are carefully tested. If one is bad, the batch > gets scrapped.   **Phil was the first person to alert me to counterfeit semis here in Australia.       -- Trevor Wilson www.rageaudio.com.au

Phil Allison <pallison49@gmail.com>: Mar 20 05:14PM -0700 Trevor Wilson wrote:   > electrolytic caps (Jamicon - horrible things, one batch of 100 I > purchased had a 30% failure rate - I had to recall half a dozen units I > serviced as a precaution)   ** I must have bought hundreds of Jamicon electro fromn WES over the last two decades- never had a single faulty one.   > to counterfeit semiconductors, I've been > caught several times. As have some of my colleagues.   ** WES had a lot of fake TO3 devices - popular ones like MJ15003 and MJ15024 in their stocks. The problem was they were reluctant to admit it or remove them from stock.   The typical attitude of such businesses is " the customer is always wrong ".     > Subsequent tests on replacement devices revealed a breakdown Voltage > (VCEO) of around 90 Volts. The original devices are specc'd at 230 > Volts.   ** That sounds like the big Sanken ones, eg 2SC2922 and 2SC3264 etc.   Never had a bad one of them from WES either.   Recently acquired stock might be different.       ... Phil

Phil Allison <pallison49@gmail.com>: Mar 20 08:28PM -0700 Trevor Wilson wrote:   > **Phil was the first person to alert me to counterfeit semis here in > Australia.   ** My god, when was that?   I have been seeing fake MJs since 1980.     .... Phil

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Mar 21 02:32PM +1100 On 21/03/2017 2:28 PM, Phil Allison wrote: >> Australia.   > ** My god, when was that?   > I have been seeing fake MJs since 1980.   **A long time ago. I couldn't say when. I buy all my non-Jap semis from Element14 or RS and have done for a long time. No problems with those guys.     -- Trevor Wilson www.rageaudio.com.au

Phil Allison <pallison49@gmail.com>: Mar 20 09:09PM -0700 On Tuesday, March 21, 2017 at 2:38:24 PM UTC+11, Trevor Wilson wrote:   > > I have been seeing fake MJs since 1980.   > **A long time ago. I couldn't say when. I buy all my non-Jap semis from > Element14 or RS and have done for a long time. No problems with those guys.   ** I bought MJs and Hitachi TO3 mosfets from authorised dealers long before the likes of Farnell & RS arrived here.     .... Phil

John Robertson <spam@flippers.com>: Mar 21 08:34AM -0700 On 2017/03/19 7:13 AM, Cursitor Doom wrote: >> assemble this thing? With some kind of right-angled soldering iron?   > I'm x-posting this to a more appropriate forum, Sylvia, the guys there > will be better able to assist you with this...   You may be able to find your BF472s sourced from India:   http://www.diyaudio.com/forums/solid-state/269984-bf471-472-good-replacement-2sa1381-2sc3503.html   I did a search and no BF numbers showed up, however they did manufacture the device recently according to the referenced PDF. You may have luck tracing the part through CDLI's distribution network. It never hurts to ask!   I would also check T710 (BF458) and T707 (BF199) as well though before ordering anything. A simple gain test should suffice. Try to find a reliable source for these transistors, there are a lot of Chinese (etc.) fakes out there!   Have you upgraded the electrolytic capacitors in your scope? They are most likely well past their Best-Before date!   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

"Nicholas R Forystek" <randall@sosouix.net>: Mar 21 07:38AM -0600

avagadro7@gmail.com: Mar 20 12:02PM -0700 the S5 female was bent out by the dealer. Is there an insert or DIY fix for too large females ?

Jeff Liebermann <jeffl@cruzio.com>: Mar 20 09:56PM -0700 > the S5 female was bent out by the dealer. Is there an insert or DIY fix for too large females ?   I had the same problem on a media player. The earphone plug just rattled around in the jack and was intermittent. It was a piece of junk and not worth fixing, but I just couldn't throw it away. So, I built a pigtail, with a male 3.5mm plug on one and a female 3.5mm receptacle on the other. To increase the plug diameter, I just built up the plug diameter by applying some solder to the plug. I also reamed out the jack to a slightly larger hole size so the soldered plug would fit. I'm not very proud of this jack but it was cheap, easy, and worked long enough for me to find a better player.   -- 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

avagadro7@gmail.com: Mar 20 11:40PM -0700 https://goo.gl/kDK0d3   There's a group of 'schematics'   Serious work fir 2 channels but mono's OK ...not sure if S5 delivers mono.   There is the problem of a silicone sheath ground 'wire' in there ? If so heating the tip burns off the Si prob crimped in...is this correct ?   How about an AL or copper rectangle placed into the female n secured via a bend n run on the case ?

makolber@yahoo.com: Mar 20 10:58AM -0700 > As far as I can tell, the components in question are not custom. IC 503 is a > standard dual op-amp whose DC output voltages start creeping up until it > reaches Vc or 12 volts and then the positive half of the signal is clipped.   there are either schematic documentation errors or design errors re IC 503   The + inputs to IC503 don't appear to have ANY DC connection, all connections are via caps. The DC voltage on the + inputs is therefore undefined. This is is either a design error or a documentation error. If DC voltage is being set by the the cap leakage, then that is your problem. Use a 100K connected to a variable DC supply and see if you can't move the DC voltage to the correct value. If you can, then you should be able to figure out the rest. m

"David Farber" <farberbear.unspam@aol.com>: Mar 20 04:04PM -0700 > correct value. If you can, then you should be able to figure out the > rest. > m   I was wondering the same thing! I will check and report back to you.   Thanks for your reply. -- David Farber Los Osos, CA

Jon Elson <jmelson@wustl.edu>: Mar 20 02:55PM -0500 > work when connected to 50 or 60HZ mains. Please can someone give me an > explanation on how these circuits work, how to test both circuit and > compressor? Thanks The problem is the motors have no provision for starting, that is supplied by the motor drive circuit that gradually increases applied voltage and frequency as the motor picks up speed.   If the windings are not shorted to the housing, the motor is most likely good. (Can't test the compressor as a whole so simply.) The drive circuits are VERY complex, probably using IGBTs and a logic circuit to drive them, which likely has a microprocessor in it. I'm not sure we can really tell you how to test the drive circuit on such a forum as this. And, be aware there are dangerous voltages in such circuits.   Jon

Stijn De Jong <stijndekonlng@nlnet.nl>: Mar 20 11:18AM -0800 On Mon, 20 Mar 2017 14:53:09 +0100, Carlos E. R. wrote:   > white background instead of black. There I switch off the WiFi, than on > again, and it instantly connects to my WiFi remembering its password.   > This behaviour started about last November or December.   As I recall, my WiFi used to scan and show all the WiFi networks, and for those that I tapped on, it would first ask for the password and then always remember it from thence forward.   Now, it won't even scan, and yet, other apps (like Fritz WLAN) see the AP SSIDs quite clearly, and, if I *connect* to the network once manually into Android WiFi settings, then it remembers it from thence forward.   Funnily, if I don't connect, then it won't remember neither the SSID nor the passphrase, which is odd to say the least.   Anyway, my next factory refresh should solve whatever setting it was that screwed it up. I screw with Android settings often so this is just a nit in the scheme of things. I just don't understand why as what Jeff noted is good but I don't think it applied to my situation (which itself, admittedly, is different than most since I screw with settings all the time).

avagadro7@gmail.com: Mar 20 12:06PM -0700 CRC electronics cleaner at Walmart.   ask Al for a switch lubricant   http://www.alliedelec.com/chemicals-adhesives/lubricants/

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