Yes due to the hard access to the upside down led strip and being so close to the floor, I will probably prepare some handmade adapter with + and -. contacts at the proper place to push current to the strips one by one and see which one needs a proper voltage.
Thanks
edugimeno
Badcaps Veteran
Last Activity: 11-05-2024, 01:26 PM
Joined: 05-30-2017
Location: Spain
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Ok thanks but these led strips have been working properly at this restaurant for several years, and I've seen many lines coming down the wall to provide extra power supply points mid-length, but for some reason a big chunk of the whole setup started failing and I need to find out how to repair it without having to remove the whole thing, which is very long and very uncomfortable to work with, as it is installed facing down under a frame that's like 2-3 inches above the floor levelLeave a comment:
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Ok I will start supplying 12V on all connection leads I see and try to find out whats wrong after I see the results
Thanks a lot!Leave a comment:
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Thanks, but the problem is that the failing section is very very long and implies 2 large walls and 2 columns (4 sides each obviously) , hard to find where the connections come from (somewhere behind the panels, can't see them) and where the sections are joined together. I will give it a try thou
ThanksLeave a comment:
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Ok yes this is something I can try and it's not that hard, as there are +/- leads everywhere at the cut points...
So you think some power points have a bad connection? Don't you think a faulty led would do this?
What would be your procedure, I mean, if I start applying 12V to all points in the faulty section, what would I do if I find a point where the extra 12v stops the flickering?
THANKS!Leave a comment:
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Finding the wrong part at a loooong led strip, part works fine, part flickers, all parallel...
Hi There!
I'm trying to help my friend who owns a restaurant be just bought.
He has a very long LED strip running along all the walls and columns. The strip is attached facing down 2in above the floor, using a wall panel that ends in a metal rail that finishes the panel underneath
It's stuck using, I guess, the 2 sided tape that comes with the strip
The issue is that like 1/2 of the full length, including 1/2 one wall, another entire wall, and one column, flickers after 4 or 5 minutes ON. Particularly it flashes staying OFF most of the time and flashing ON for 1 tenth... -
Well I left the board "as is" working fine at the client's. He really needed it there because it's a hotel and it was full this last weekend and temps were really high (100-105F) outside. I guess if he doesn't call me with new issues I will have to leave it, but if there's anything, I will do what you said
ThanksLeave a comment:
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Ok, final update on this. I went to test the board. Initially I connected the 3 fans directly to mains, thru the multimeter. They started correctly (no capacitor issues) and took 2.5Amps (rated at 0,82A each), All good. Time to check the board
First I plugged only the 230 mains input. No issues, checked consumption to 8-15mA
Then I plugged the fans, with the control RJ45 plug still out (no start), and I got an arc by the mains plug in 3 seconds....turned all off and scratched the charcoaled areas of the board to remove all carbon assuming this would be it
To summarize, step by...Leave a comment:
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I didn't even think of this, carbon conductivity. After first repair I placed, as you can see, a bare copper wire on top of the board, that was charcoaled...maybe this cause a shortcut L-N...which is pretty close. Last time I've used normal household wire, with its plastic wrapping, and I didn only peel the ends. I will double check again before we plug it in tomorrow, probably measuring current with direct drive from mains, and then current while using the board, cafefully....
Thanks!...Leave a comment:
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No the transformer is used to provide a cascade of different speeds, each winding is switched by each relay
I checked continuity between N and L and there is no shortcut
Maybe the wire was damaged
The guy is now scared to test it again as it caught fire last time....Leave a comment:
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Yes that's exactly the method I was thinking of doing next time I can go there, measure current with direct 230v drive, and then thru the board and see if the board add extra current maybe due to a internal shortcut I haven't seen
But I'm still surprised that the current was able to burn my jumper copper wire and not able to trip the 3.12A fuse... Is it right to use a motor winding copper wire for this os does it have any drawback that I didn't realize? I can't figure out how such a diameter (I believe it was 0.95mm) didn't stand a current flowing in series with a 3A fuse...
...Leave a comment:
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Fancoil.controller with current issues
Hi there! One friend called to say his fancoill (used for a main access cold Air courtain) controller caught fire, and asking if I could recover the half burnt board
He said the design was too bad as this thing was probably designed for hot water only, as the board was places right underneath the condenser radiators
I found some burnt traces and after a quick Google search for the board name (Pwr-05v-w) I could see an image of the original I was able to find where the original traces were going
The scheme seems simple, from what I understand mains gets into the while 3 lead... -
Anyone? ThanksLeave a comment:
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Grundig 39 WCP 2014 BRS. Bad BL, hack or fix?
Hi! I was given this TV. It would turn on fine but then after a while the BL would shut off while rest of functions would stay working. I assume this 99% means a shortcut in the BL so the PS detects the overcurrent and shuts off the BL pwr.
I managed to keep it up for the time enough to enter into settings and turn down the backlight to 50% which seemed to help. I was able to watch it for some hours several days
But the other day, I went to try it and the BL didn't even start at boot up. I want to repair it but: This is a spare TV that I want to keep at a house that I seldom... -
Yes, I find that in electronics repair its more difficult than in other jobs to provide an accurate quote and to charge for the real time you have spent. I guess mechanic car repair is kind of alike. You have an impression of what could be broken, given your own experience in similar products you have repaired (TV shows no image, but has sound, you EXPECT to replace the backlight strips), or just after a quick examination (SMPS chopper transistor shows a burnt spot, you EXPECT to replace the Q and call it good) but there there are many times that you end up spending a long time you could not have...Leave a comment:
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Yes Sam, thanks for your comment. Definitely I can't count as an experimented repairman, I have been "into" electronics for the last 35 years but always in the amateur side. I've always been an IT specialist and only recently with a morecomfortable job with more spare time, I've started offering my services sporadically to some known people and some of them have spreaded the voice so now there's like 10-15 people who call me from time to time to bring a TV, amplifier, car stereo, power supply or other weird piece of electronics that I have to repair and only very recently I have started...Leave a comment:
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Ok final update on this with conclussions. Summarizing: Client states that one of the functionalities of the board (pellet ash cleaning motor) is not starting, neither during normal operation, nor during tests screen,
There is one relay in a row of several, that clearly drives the 230V ac voltage to the cleaning motor. Before any other test, I try to apply 24v dc to all relays directly and they all click on-off but this-supposedly-faulty -one goes like slow and weak. I measure all driver transistors and all give the same readings but the ones driving this relay. It seems that 2 transistors...Last edited by edugimeno; 05-15-2024, 12:25 PM.Leave a comment:
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Im realizing... when I applied 24V across the protecting diode, all I did was applying +24v to the upper rail (already common +24v for all relays) and 24v [B]GND [/B]to the other side of the coil, which is directly fed by both transistors, and driven to gnd by one of them when their source signals becomes high. Is putting their collectors to GND a source to backcurrent? I don't see how this can damage them. Not trying to argue, just not able to see it.
And like I said, when one transistor switches on, the other, in parallel like an OR gate, would be "suffering" this backcurrent...Leave a comment:
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Im a little confused on this. Per the schematic, it looks like these relays have 2 transistors that will drive the coils, mounted in parallel, like different sources will be able to independently drive them high.
If having fed 24V manually at the coil lead would damage the transistors, what if one transistor drives 24 to the coils? It would be also getting 24V in reverse to the other transistor in paralel right? So this leads me to think that if it's me who applies the 24V across the coils leads, the voltage seen by the transistors would be the same as if the other transistor would be providing...Leave a comment:
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Thanks. I directly injected 24V to the relay coils (across protetion diodes). I checked polarity, in this case the common point is the positive side, and then GND is switched by the driver transistors
I haven't checked all those parameters. All I have checked is the protetion diode and it tests OK
Yes the K1N transistor is an BT3904 NPN transistor which has Vce=40v (this board is powered at 24v), and has Ic=0.2 and P=350mW while the old one 1GW has Ic=0.1 and P=250mW, so it looks like it would work fine
Thanks!Leave a comment:
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