- World's Worst Soldering! - 20 Updates
- Harman Kardon 930 lost channel. Hoe to trouble shoot ? - 5 Updates
| Chris <cbx@noreply.com>: Oct 07 04:41PM On Sun, 07 Oct 2018 09:35:55 -0700, tabbypurr wrote: > photos not too clear, but looks like you need to be applying more > solder. If there's black muck involved, clean the joint better. mebe theres something wrong wiht your browser as they show up v. clear indeed on my monitor at any rate. outstandingly clear in fact i would say. rotten soldering! |
| Jeff Liebermann <jeffl@cruzio.com>: Oct 07 10:36AM -0700 On Sun, 7 Oct 2018 16:08:34 -0000 (UTC), Cursitor Doom >https://www.flickr.com/photos/128859641@N02/45109856712/in/dateposted-public/ >https://www.flickr.com/photos/128859641@N02/44247281105/in/dateposted-public/ >As you can see, the "world's worst" tag was no exaggeration! There may be hope for you yet: 1. How many watts is your soldering iron? It looks like the mess made by too low power or too fine a tip. 75 watt seems about right. 2. Is the soldering iron temperature controlled? If yes, raise the temperature and work fast. Mine runs at 750F (400C) for 60/40 lead-tin. If no, go shopping and buy a decent adjustable temperature controlled soldering station. Get a fine tip for fine work, and a thicker tip for the big stuff (so that the tip doesn't go cold as soon as you touch the work). 3. Are those 3300uF 25V caps 85C caps or 105C? The photo looks like 85C. If so, they'll last about 6 months inside a hot oscilloscope. 4. Clean the enamel off the wires with sandpaper before you solder. Tin the wire ends before attaching to a lug or PCB rivet. I've dragged some of the local hams into my palatial office and demonstrated how easy it is to solder properly with a decent soldering iron. They're usually amazed at how well THEY can solder using my equipment. That's when I discover that they're using something from Radio Shack or that came with their childhood wood burner kit. I just did a quick scan of what's available on eBay and noticed that they now have OLED display aftermarket temp controllers for HAKKO soldering irons. I'm tempted: <https://www.ebay.com/sch/i.html?_nkw=soldering+station+temperature+controlled> Also, if you don't have a hot air SMD workstation, this might be a good time to get one because they often include an adjustable temperature controlled soldering iron. -- 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 |
| Steff <e-post.nu@gmx.com>: Oct 07 07:56PM +0200 Really bad.. Im suprised that the diods are still alive after that burn. Have to be a newly employed that did not get His/her 2hr education before doing the job Den 2018-10-07 kl. 18:08, skrev Cursitor Doom: |
| tabbypurr@gmail.com: Oct 07 11:19AM -0700 On Sunday, 7 October 2018 17:41:44 UTC+1, Chris wrote: > mebe theres something wrong wiht your browser as they show up v. clear > indeed on my monitor at any rate. outstandingly clear in fact i would say. > rotten soldering! Turns out you're right, the test card shows the grey scale is a mess. Settings can't fix it. Ah well... NT |
| tabbypurr@gmail.com: Oct 07 11:22AM -0700 On Sunday, 7 October 2018 18:36:07 UTC+1, Jeff Liebermann wrote: > Also, if you don't have a hot air SMD workstation, this might be a > good time to get one because they often include an adjustable > temperature controlled soldering iron. It's also fair to say that even with a right piece of junk one can solder properly if you have the skill. In a drawer somewhere I have a 1950s Solon where the tip hangs loosely, but it still solders ok. NT |
| John Robertson <spam@flippers.com>: Oct 07 11:58AM -0700 On 2018/10/07 10:36 AM, Jeff Liebermann wrote: > controlled soldering station. Get a fine tip for fine work, and a > thicker tip for the big stuff (so that the tip doesn't go cold as soon > as you touch the work). A good soldering station and good hand tools (eg. - strong needle nosed pliers, shard edge clippers) are indispensable for repairing equipment properly. > 3. Are those 3300uF 25V caps 85C caps or 105C? The photo looks like > 85C. If so, they'll last about 6 months inside a hot oscilloscope. I spotted what looks like "10..." curling over the edge on the edge of one of the caps, so he is at least using 105C caps. The caps should be secured though. > 4. Clean the enamel off the wires with sandpaper before you solder. Sandpaper may be too aggressive if a rough grit, that can introduce scratches to the copper leaking to the potential for breakage. I suggest using something more like wet/dry emery cloth of about 1000 grit - true, it is another sandpaper, but less likely to scratch. > Tin the wire ends before attaching to a lug or PCB rivet. The invented bridge rectifier was poorly made for the space allowed, and those bridge modules are readily available. If you need to make a bridge module wrap the leads at least one loop around the others for a mechanical junction prior to soldering. Then there less risk of a solder joint breaking and introducing random loose parts into your equipment... > have OLED display aftermarket temp controllers for HAKKO soldering > irons. I'm tempted: > <https://www.ebay.com/sch/i.html?_nkw=soldering+station+temperature+controlled> This looks handy - so I've ordered a couple for the shop: https://www.ebay.com/itm/352464262209 Nice to be able to check calibrations by comparison. > Also, if you don't have a hot air SMD workstation, this might be a > good time to get one because they often include an adjustable > temperature controlled soldering iron. John :-#)# |
| <698839253X6D445TD@nospam.org>: Oct 07 06:58PM Cursitor Doom >Check it out and enjoy at my expense: >https://www.flickr.com/photos/128859641@N02/45109856712/in/dateposted- >public/ Cool >and... >https://www.flickr.com/photos/128859641@N02/44247281105/in/dateposted- >public/ Now that is an interesting bridge rectifier. Here a raspberry replacing a big chip: http://panteltje.com/panteltje/raspberry_pi_FDS132_matrix_display_driver/index.html That thing has been working all day now since Dec 2013 without a glitch. http://panteltje.com/pub/matrix_display_zoom_IMG_6609.JPG Nothing to worry about. Even older, 1985 or so, still works: http://panteltje.com/pub/8052AH_BASIC_computer/8052AH_BASIC_computer_wiring_img_1756.jpg >As you can see, the "world's worst" tag was no exaggeration! Na, it is OK. I sort of like soldering, but only 60/40, maybe it is the lead ... :-) http://panteltje.com/pub/z80/graphics_card_top.jpg http://panteltje.com/pub/z80/graphics_card_bottom.jpg have many boards like that.... Scroll down can you find the SMDs on the board? http://panteltje.com/panteltje/raspberry_pi_dvb-s_transmitter/ that is some Giggle Hz stuff too. It is still working, in fact added some stuff. Soldering is simple. You need a good temperature controlled soldering iron, some solder wick, some 60/40, and there you go. I count to 14 at 320 C for it to flow ... around pins. :-) |
| tabbypurr@gmail.com: Oct 07 12:57PM -0700 On Sunday, 7 October 2018 19:58:49 UTC+1, John Robertson wrote: > module wrap the leads at least one loop around the others for a > mechanical junction prior to soldering. Then there less risk of a solder > joint breaking and introducing random loose parts into your equipment... People often overestimate the strength of solder - it's close to zero. Always make some sort of mechanical bond first, or reliability will not be yours. NT |
| Cursitor Doom <curd@notformail.com>: Oct 07 08:06PM On Sun, 07 Oct 2018 10:36:05 -0700, Jeff Liebermann wrote: > There may be hope for you yet: Unfortunately not! > 1. How many watts is your soldering iron? It looks like the mess made > by too low power or too fine a tip. 75 watt seems about right. I have 15W, 25W, 40W and 80W irons. This atrocity was carried out with the 15W one which has a pointed tip for some reason. > soldering station. Get a fine tip for fine work, and a thicker tip for > the big stuff (so that the tip doesn't go cold as soon as you touch the > work). You're very kind in attributing this train wreck of a repair to my having the wrong tools, Jeff. Sadly I don't believe it's the case. This kind of work requires a steady hand and a keen eye and I possess neither. > 3. Are those 3300uF 25V caps 85C caps or 105C? The photo looks like > 85C. If so, they'll last about 6 months inside a hot oscilloscope. I followed the original spec as far as possible. The originals were 5500uF, 30VDC and 85C. I couldn't get the right capacitance within the space available so used 33's in parallel. The old 85C's lasted for decades so your 6 month assessment may be a bit pessimistic. > 4. Clean the enamel off the wires with sandpaper before you solder. > Tin the wire ends before attaching to a lug or PCB rivet. Yes, I did do that. I know what I *should* do but it doesn't help. > Also, if you don't have a hot air SMD workstation, this might be a good > time to get one because they often include an adjustable temperature > controlled soldering iron. Can you imagine the carnage I'd leave behind attempting SMD stuff?? :-D -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition. |
| John Larkin <jjlarkin@highlandtechnology.com>: Oct 07 01:26PM -0700 On Sun, 7 Oct 2018 11:58:41 -0700, John Robertson <spam@flippers.com> wrote: >scratches to the copper leaking to the potential for breakage. I suggest >using something more like wet/dry emery cloth of about 1000 grit - true, >it is another sandpaper, but less likely to scratch. I scrape magnet wire with an x-acto knife. That leaves a shiny surface that wets nicely. I think the professional wire strippers use rotating knives. https://www.dropbox.com/s/27px827y9ed4mev/T850_L1_Tinned.jpg?raw=1 https://www.dropbox.com/s/zcbo3i2krozy7g0/T850B_L1.jpg?raw=1 A serious high-power, controlled temp iron is basic to good soldering. I like my Metcal. -- John Larkin Highland Technology, Inc lunatic fringe electronics |
| tabbypurr@gmail.com: Oct 07 01:34PM -0700 On Sunday, 7 October 2018 21:06:43 UTC+1, Cursitor Doom wrote: > > time to get one because they often include an adjustable temperature > > controlled soldering iron. > Can you imagine the carnage I'd leave behind attempting SMD stuff?? :-D 15w is way too low power for what you're doing there. 25w & 40w are the ones to be using. 15w is better for smd work, hence the pointed tip. You'll learn. We'll give you a hard time till you do. NT |
| <698839253X6D445TD@nospam.org>: Oct 07 08:36PM John Larkin wrote >I scrape magnet wire with an x-acto knife. That leaves a shiny surface >that wets nicely. I think the professional wire strippers use rotating >knives. I just select 375 °C as soldering temperature, that burns the magnet wire insulation, and then you can just tin it. Scraping damages the wire. But watch out for the terrible possible toxic smell. |
| John Robertson <spam@flippers.com>: Oct 07 01:41PM -0700 On 2018/10/07 1:26 PM, John Larkin wrote: > knives. > https://www.dropbox.com/s/27px827y9ed4mev/T850_L1_Tinned.jpg?raw=1 > https://www.dropbox.com/s/zcbo3i2krozy7g0/T850B_L1.jpg?raw=1 I have a brush that uses fiberglass. Cleans quickly, bends a bit to get the rounding needed, and doesn't run any risk of nicking the wire. Something like this: https://www.ebay.com/itm/191126624992 Also polishes edge connections, etc. a very useful tool. > A serious high-power, controlled temp iron is basic to good soldering. > I like my Metcal. For regular board work I like my Weller stations with the magnetic temp controlled tips, I mostly use the #7 medium or thin screwdriver tip. 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." |
| "jfeng@my-deja.com" <jfeng@my-deja.com>: Oct 07 03:06PM -0700 > and then you can just tin it. > Scraping damages the wire. > But watch out for the terrible possible toxic smell. I use a match to burn off the insulation. Sand paper also works without nicking the wire. I think I saw some kind of chemical stripper in the electronics catalogs, but I never tried those. |
| Ralph Mowery <rmowery28146@earthlink.net>: Oct 07 06:33PM -0400 In article <ebfb52f0-b273-43e1-8684-4b7f64278e9f@googlegroups.com>, tabbypurr@gmail.com says... > 15w is way too low power for what you're doing there. 25w & 40w are the ones to be using. 15w is better for smd work, hence the pointed tip. > You'll learn. We'll give you a hard time till you do. It seems to me that instead of a certain wattage of irons, the way to go now is an iron with high wattage, say 50 or 70 watts but is temperature controlled. Then match the size of the tip to the size of the work. Those hot air stations from China for about $ 60 seem to work fine for me as I am just doing it as a hobby and only use it once ever couple of weeks. The hot air works well for the heat shrink tubing and sometime to remove a daughter board from the mother board if it only ha a few pins. The iron heats fast and comes with several tips. Stay away from any solder that is not 60/40 or better 63/37. Size the solder to the job. Maybe adding some extra flux will help you. |
| Ralph Mowery <rmowery28146@earthlink.net>: Oct 07 06:37PM -0400 In article <c18c654d-d03a-4922-aecb-630adea5516e@googlegroups.com>, jfeng@my-deja.com says... > > Scraping damages the wire. > > But watch out for the terrible possible toxic smell. > I use a match to burn off the insulation. Sand paper also works without nicking the wire. I think I saw some kind of chemical stripper in the electronics catalogs, but I never tried those. The high temperature iron sometimes works and sometime not depending on the wire. I usually use a Bic lighter and one of the Scotchbrite pads to finish cleaning the wire. |
| John Larkin <jjlarkin@highlandtechnology.com>: Oct 07 03:46PM -0700 On Sun, 07 Oct 2018 20:36:00 GMT, <698839253X6D445TD@nospam.org> wrote: >I just select 375 °C as soldering temperature, >that burns the magnet wire insulation, >and then you can just tin it. Beldsol and some similar wires are meant to be thermally stripped. >Scraping damages the wire. Not #14! -- John Larkin Highland Technology, Inc lunatic fringe electronics |
| DecadentLinuxUserNumeroUno@decadence.org: Oct 08 01:00AM > You need a good temperature controlled soldering iron, > some solder wick, some 60/40, and there you go. > I count to 14 at 320 C for it to flow ... around pins. 60/40 is for plumbing. The electronics industry settled on and proved to be the best 63/37 and for decades it was. This RoHS shit is the worst thing the world ever did. Metallic form lead is not dangerous to the environment. If it were, there would be huge lead levels around all the damned police shooting ranges in the nation. There is not. |
| bitrex <user@example.net>: Oct 07 09:36PM -0400 On 10/07/2018 12:08 PM, Cursitor Doom wrote: > As you can see, the "world's worst" tag was no exaggeration! Eh. This was the soldering job in a commercially-sold SMPS bench power supply from an Amazon.com reseller, IIRC, this was how it looked when it left the mfgr, I took this photo immediately after opening the enclosure and pulling the PCB (it had stopped working! can you believe it) <https://www.dropbox.com/s/65km6pbq8wzch54/IMG_20171005_104357775.jpg?dl=0> |
| Jeff Liebermann <jeffl@cruzio.com>: Oct 07 07:09PM -0700 On Sun, 7 Oct 2018 11:58:41 -0700, John Robertson <spam@flippers.com> wrote: >scratches to the copper leaking to the potential for breakage. I suggest >using something more like wet/dry emery cloth of about 1000 grit - true, >it is another sandpaper, but less likely to scratch. I'm using 400 grit wet/dry sandpaper for removing enamel. No reason other than it seems to last longer than the finer grits and I have a fair number of sheets. For very thin magnet wire or litz wire, I use finer sandpaper. If I want to scrape off the insulation, I use a moderately dull edge kitchen knife that won't cut or gouge the copper wire. If I try to solder magnet wire that still has some coating on the wire and was not tinned, I get a black carbonized blobs, like in the photo. >This looks handy - so I've ordered a couple for the shop: >https://www.ebay.com/itm/352464262209 >Nice to be able to check calibrations by comparison. I have one of those. It's a counterfeit clone and is not made by Hakko. This is what the real FG-100 looks like: <https://www.ebay.com/itm/New-Hakko-FG100-02-Thermometer-Fahrenheit-Fg-100-US-Authorized-Dealer/361688237097> Note the price. I haven't bothered to verify the calibration on mine, but it seems to indicate what I would expect. -- 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 |
| Steff <e-post.nu@gmx.com>: Oct 07 10:06PM +0200 > I also want to point out that soldering as an electrician is probably different from soldering in a receiver. I recommend getting an old piece of electronics to try replacing a component and see if you can do it reliably. Better to find out on a piece of junk. Older circuit boards have a higher failure rate due to excessive heat. I had an old Sony board where the pads lifted too easily with a 700° tip but were OK with a 600° tip (Metcal). > I like old HK gear and would prefer to hear you have it working again. > G² I love HK products and specially the older septon ones. So giving life to my old 930 have high priority for me as well. Mu dad buy it new and had some JNL speakers with it.. I got is when I left home in 1979 as a 19 year old and it have been with me ever since, so ofcourse I will try to keep it alive. Best Amp I ever had. I did have a Sansui that was OK but still this one is the best. I also have an oscilloscope and multimeter så I will try to separate the pre amp from the poweramp and se if the prombel is located in the power amp for sure. I already order some effekt transistors to prepare to change them since i Still belive it is in the "end transistors" I found 3 off them in Italy for a decent price (25 USD for 3) So thanks so far for all advise I keep updating until it works hopefully with all you guys help. Sorry for my English My native language is Swedish so bare with me please. |
| John-Del <ohger1s@gmail.com>: Oct 07 04:58PM -0700 On Sunday, October 7, 2018 at 4:06:45 PM UTC-4, Steff wrote: > So thanks so far for all advise I keep updating until it works hopefully > with all you guys help. > Sorry for my English My native language is Swedish so bare with me please. Sad to say, you're English is better than many native speakers... I've changed many hundreds of outputs over the years, and have never seen one "open". High current/wattage devices *generally* fail catastrophically, not open benignly, although there certainly are exceptions to every rule. So with a basic DMM, check for low ohm shorts. Out of circuit they should read a few hundred K ohms minimum if anything at all. On the diode scale, you should get two combinations that read about 0.600 if the outputs are silicon. I can't speak for your particular HK, but most amplifiers (not all) use a common speaker protection relay so a shorted transistor on one side will prevent the speaker relay from engaging, rendering both sides mute. Your HK being an older vintage piece may be configured differently. |
| jurb6006@gmail.com: Oct 07 06:44PM -0700 OK. Read. First of all that is a good piece. Not the most advanced but so what. The amp is a standard quasi comp design, not hard at all. Now, first of all for the outputs 2N3773s would be great. that is a JEDEC (US) number though and you might not be able to get them there. the originals are TO-3, try to stick with that and not use the plastic equivalent, I don't like how they mate to the original holes. the original design calls for less than a certain thermal resistance there and upsetting that is not good. If you got a friend in the US those 2N3773s are not expensive and fit alot more than just that amp. So take the outputs out. Short the base and emitter terminals of each as well as TR 624 and 604 (?) the bias transistors emitter to collector, if unsure of the basing just short it all the way around. Not with the outputs though, the basing is clear enough, the pins are E and B, those are what you short. (not to the other transistor...) Now use a DBT for the fuse whether it is blown or not. When powering up the lamp should light then dim gradually until it is about out. The voltage at the speaker outputs should be zero or close. If not, one of the drivers may be shorted, if you care to that can be checked with no power using the DVM on the ->|- scale of course. With a scope you should even be able to see an audio waveform at the output, put on some rock music, the waveform should be pretty much symmetrical up and down. DO NOT connect a load like a speaker or dummy or you will blow the drivers if they aren't already. Once you got that all straightened out and have it with not outputs in then put in the new ones. Leave the short across that bias transistor and connect speakers. There will be much distortion at low levels getting almost clean as you approach maximum power. Once it passes that test, remove power and discharge the filters. Remove the short from one of the bias transistors, power on, if that light does not dim as it did before there is a fault in the bias, do not run it like that load or not. All this assumes the resistors that join at the speaker outputs have been checked and are not open. Usually there is no smoke or burn so they need to be tested electrically. forget the exact value, to measure it accurately you need the right equipment, either a meter on which you can null the lead resistance or a Kelvin connection. If it is not open, 95 % of the time it is good. Those are the live tests mainly, there is not reason not to check the transistors and low value resistors before even starting the powered tests. Main thing you want id no open transistors and no shorted transistors. These methods have made me a bunch of money because I do not waste silicon. And BTW, did you say something about 3 of them ? They need to be replaced in pairs. If one shorts, the feedback in the circuit tries to pull the voltage back to zero and that can exceed the design maximums of the other output in the channel. If the original AC fuse is not blown use that meter and look for open resistors all over those output circuits, if anything shorts something has to give. If what gives it in the bias circuit you could lose your new outputs in less than a second, that is why the first run is done with zero bias. As far as making sure the problem is in the output stage, just take a pair of RCA cables and switch left and right. If the problem switches to the other channel then all this is moot and now we are in the preamp. The scope will come in VERY handy if that is the case. If it does go to the other channel a mono switch would be nice but I do not wee one. In this case you can just short the volume controls together, either the top (not grounded) side or the wipers, doesn't matter, if you get both channels then the problem is before that. At that point there ain't much left. (ain't is a word used only by those with exceptional command of the English language lol) |
| stratus46@yahoo.com: Oct 07 06:49PM -0700 On Sunday, October 7, 2018 at 1:06:45 PM UTC-7, Steff wrote: > So thanks so far for all advise I keep updating until it works hopefully > with all you guys help. > Sorry for my English My native language is Swedish so bare with me please. Hi Steff, Your English is way better than my non-existent Swedish. So you have a scope and meter and are way ahead of the game. Most folks don't realize they also have a test generator called their computer. I make test signals frequently with Adobe Audition 3. Audacity is free and works as well. I would bet money the output transistors have not failed. I got the service manual from HiFiEngine and noted the only thing between the speaker connector and the amplifier is the speaker switches for local and remote speakers. There is no 'protection' or fault detection or relays The first thing to do is verify all the power supplies are good. I can't make out if the amplifiers run on +/- 34 or +/- 39 Volts. While the power amps have twin power supplies, the signal system (AM,FM, phono and tone controls) run off the left channel transformer (+B2, -B2) The B3 supply should be around 20 Volts positive and should have nearly no ripple. You'd see ripple with your scope set to AC coupling and turn up the sensitivity to 50 mV per division. I would expect it to be 0-5mV. If I had it on the bench I would run a 1KHz signal into AUX 1 or 2 and verify normal signal at the 'preamp out' jumpers on the back of the unit. If you want to test tone controls you can generate a 'chirp' (frequency sweep) in Audacity and observe the output on the scope. I predict no problems at preamp output. With no speakers connected (speaker switch off is the same thing) there should be sound on the headphones even if the speaker fuses are blown. Good luck and let us know. G² |
| jurb6006@gmail.com: Oct 07 07:09PM -0700 On Sunday, October 7, 2018 at 6:58:59 PM UTC-5, John-Del wrote: > Sad to say, you're English is better than many native speakers... Yup. the mistakes are mistakes, not laziness. > I've changed many hundreds of outputs over the years, and have never seen one "open". I have, but they are usually intermittent. > I can't speak for your particular HK, but most amplifiers (not all) use a common speaker protection relay so a shorted transistor on one side will prevent the speaker relay from engaging, rendering both sides mute. Your HK being an older vintage piece may be configured differently. Actually none at all, there is no protection, no relay, delay or even output current limiting. It is still a good piece. The outputs are hefty enough to handle a sub 4 ohm real load, looks like a fairly healthy FM as well with the totally shielded front end. It's not PLL stereo but if it is stable there is no reason it can't perform. It doesn't have the best tone controls of lo and hi cut filters but eh, can't have everything. |
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