#qi-hardware IRC log for Friday, 2016-03-11

arossdotmeim not so sure that the Samsung cells are right for a few amp constant load looking at the review on that site03:12
whitequarka few amp is generally not a problem for cells03:48
whitequarkonce you're looking at >5A or 10A you start having problems03:48
wpwrakeintopf: on the topic of fixing monitors by swapping capacitors: the important parameters are capacitance, voltage, and mechanical compatibility12:08
wpwrakif you can't get the right capacitance or voltage, you can always use some larger value. you may be able to get away with slightly smaller values than the original, too, but you'd be taking chances.12:10
eintopfwpwrak: https://youtu.be/df1q81l_d0M?t=4m24s12:11
wpwraksize increases with capacitance and voltage, so this limits how far you can exceed the original values.12:11
eintopfI think I need these, but I better lookup again which capacitance they use12:11
eintopfand I don't do experimenting stuff :D12:11
eintopfjust replace the same values12:11
wpwrakpcb looks familiar :)12:12
wpwrakthe board12:12
wpwrakthe values are written on the caps. very easy to find those values :)12:12
eintopfyes, there is no unknown stuff on the board12:13
eintopfit's very open hardware friendly if you have the chance to open it12:13
eintopf-> Problem: Blinking power led, the display do not start properly. The main reason is the capacitors of internal power supply.12:13
eintopfexact my problem12:13
wpwraknow, you have to be careful about size. first, of course, you want to make sure the contacts have the same arrangement. those caps usually have them on one side, but there are also caps that have one on either side. you want to make sure you pick the right one.12:14
wpwrakif the original size isn't available, then you may be able to use something bigger, but you have to check the available space first12:15
wpwraki'd also check for burnt components. e.g., on my two problem monitors, i have various spots and components that look overheated. so i'm not sure just fixing caps will solve the problems.12:16
wpwrakalso, you don't need to replace all the caps, just the ones that look defective. you can tell by looking at their top. if it bulges to the outside or has even ruptured, the cap needs replacing12:18
wpwrakif the top is nice and flat it's probably okay12:18
eintopfyes ok.12:18
eintopfand the sizes, I solder them out and take them to the electronic market12:19
eintopfand say the people "I need exact the same but not from china pls"12:19
eintopfokay, I mean with china, not the cheapest parts12:19
eintopfwhich are available12:19
eintopfI think they all comming from china12:20
xiangfuwpwrak: Hello12:27
eintopfone of them12:32
wpwrakxiangfu: heya !12:37
eintopfI have all12:38
eintopfmaybe I should open the case at first and look into12:38
wpwrakeintopf: yageo is also a reputable company. so there's a chance they will last a little longer12:38
wpwrakeintopf: yes, open the case, take pictures, check if there's anything else that looks bad, write down all the values12:39
eintopfthey have all what I need from yageo12:39
wpwrakeintopf: in any case, you want to see which parts actually need replacing. you don't have to replace just everything. some caps will be perfectly fine.12:40
wpwrakxiangfu: how's life ? :)12:40
eintopfwpwrak: okay, I know what you mean12:41
eintopfwpwrak: https://www.youtube.com/watch?v=JEuPP6FKNMc12:41
wpwrakeintopf: when you look at the picture of that cap from conrad you can see the lines on the top. looks a bit like a peace sign12:42
wpwrakah yes, that :)12:42
eintopfI had some printer, then i heard some "puff and zzzzsss"12:43
eintopfI think then the elko was exploding12:43
eintopfbtw: it doesn't work after that again12:43
eintopfI just needed the stepper motors from that printer12:43
xiangfuwpwrak: We order 10 of N900, we will receive them next week.12:49
xiangfuwpwrak: I am trying to order 250 of them. but it really depends. but I THINK i can make it 50 in next week.12:50
xiangfuwpwrak: The link you sent to me. they don't ship to China. :(12:50
xiangfunot sure if they are real or not. they reply the us. they just don't ship to China12:50
eintopfstupid question: can I measure elkos with a multimeter?12:54
larscto find out the max voltage, just increase it, once it starts to smoke you found it12:56
eintopfI meant the capacitity12:59
larscto get the capacity charge it up and then discharge over resistor and measure the time it takes to discharge12:59
larscsome multimeters might support this12:59
eintopfah, ok.12:59
eintopfI have that13:00
eintopfohh, I know RC thing from study13:00
eintopf"low pass filter"13:00
larscthe datasheet says it can measure capacitance13:01
wpwrakxiangfu: sounds great ! are all those from the same source or different sources ?13:03
eintopfyes, 40/400 nF/4/40/100 µF, ± 3 %13:03
eintopfbut elko's? I thought the small ceramic one only13:03
eintopfbut I can't put the cermaic one into a normal power supply13:04
larscif it is larger than 100uF it can't I guess13:04
wpwrakxiangfu: (don't ship to china) interesting :) but their whole shipping arrangement looked a little odd, so perhaps that isn't surprising13:04
eintopfah, ok.13:04
eintopfso if I solder some damage elko, I will measure the capacity... just because I can13:04
eintopfand then check13:04
wpwrakeintopf: you'd need something like this: https://www.conrad.de/de/komponententester-voltcraft-lcr-100-101392.html13:08
wpwrakor you can just charge the cap to a known voltage, add a resistor to the terminals, measure the time it takes to discharge to a certain voltage, then do the math :)13:09
wpwrakeintopf: or this (cheaper, but without inductance): https://www.conrad.de/de/komponententester-digital-voltcraft-smd-200-cat-iii-600-v-anzeige-counts-6000-123007.html13:18
eintopfI think I just replace the ugly looking caps13:24
wpwrakyup, you can't go wrong with that :)13:30
eintopfI think I will cleanup my second workspace (currently there is a papercraft stardestroyer project) and then open the monitor13:32
eintopfI will take pictures for you!13:32
eintopfI open the case13:51
eintopftwo little pieces are falling down from the case :(13:51
eintopfI think it will hold without it13:51
eintopfanother thing got broken14:14
eintopfsome cable connector safety mechanism14:14
eintopfI thought I helped a little bit with a screwdriver14:15
eintopfbut it was to much14:15
eintopfwpwrak: https://www.dropbox.com/s/zlww8tiksajfj1y/IMG_20160311_151323.jpg?dl=0 - do they looking okay?14:16
wpwrakah, try not to break connectors :)14:18
eintopfwpwrak: do you think it's okay?14:19
eintopfwhen I put it into that again14:20
wpwraknot sure about the caps. maybe try to have them in focus ?14:22
wpwraki guess the connector will be fine14:22
eintopfwpwrak: https://www.dropbox.com/s/q04nc5ske9hpb1q/IMG_20160311_152438.jpg?dl=014:25
eintopftwo of them (at another position looks fine) but these five I need to replace them14:27
wpwrakah yes, they look rather suspicious14:47
eintopfwpwrak: i have solder them all out15:27
eintopfit think i heat my fingers too15:27
eintopfwas difficult :(15:27
wpwrakyeah, properly cooking one's own fingers can be tricky :)15:58
eintopfno the last one was most difficult16:04
eintopfand I hope I added no new other connections16:04
eintopfI go to into the city now16:35
eintopfand buy the missing parts16:36
eintopfI have all parts20:23
wpwraknow the fun begins :)20:23
eintopfwpwrak: https://www.dropbox.com/s/64qugjlq6vepbni/IMG_20160311_214103.jpg?dl=020:42
wpwrakpretty :) and now, the fireworks !20:47
eintopfI try to connect it with power21:03
wpwrakwhoa ! what was that flash at the horizon ?21:04
eintopfit works21:06
eintopfbut I got a little shock21:06
eintopfwhen I touched the power button21:06
eintopfnow I have fear21:06
wpwrak(works) great ! (shock) leave it turned on :)21:08
eintopfthank you all21:10
eintopfnow I am not frustrated anymore each morning when starting the pc 21:10
eintopfor comming back when the monitor was in sleep mode21:10
eintopftook 5 minutes to bring some picture21:10
eintopfnow I need to clean the screen21:11
eintopfI put it again on the vesa connector21:19
eintopfneed to readjust the vesa connector tomorrow21:19
eintopfbut it works21:19
eintopfand picture is somewhat better than before21:19
wpwraknice bonus :)21:32
eintopfnow I want to repair more monitors21:34
--- Sat Mar 12 201600:00

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