So you believe the short I made in the secondary should not be enough to blow the mosfet driving the primary?
Thanks!...
edugimeno
Badcaps Veteran
Last Activity: 03-08-2025, 02:06 PM
Joined: 05-30-2017
Location: Spain
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Are we talking about the guy circled in red in this picture? Testing on-.board it measures 0,5v in one direction and 1.2v in the other. His "twin" on the other transformer has near zero values on tboth ways, but the suspect side has a blown mosfet connected to it..
So you believe the short I made in the secondary should not be enough to blow the mosfet driving the primary?
Thanks!... -
Yes, what looks weird is that the short right now is at the SECONDARY of the transformer powered by that mosfet, not the primary. Would a short in the secondary make the Q driving the primary blow so hard? and quick? Or should I look for something else. Maybe I should try to link all this to the original issue of the clicking noise and only 2-3V delivered at output...
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Updates... I fu**d up... Went there (I have it at my country house), checked for visible sparks at full dark. Nothing on either side
Used the wood spoon method that suggested, and found the noise coming from the larger transformed in the middle of the board.
Took it out of the chassis and started redoing some solders around the transformers area. Put it back in place and turned on. Bang...At least it was quick and felt like whatever exploded was instant and damaged no more.
Found one of the 2 (probably) chopper transistors split into 2 pieces. You can see the pictures. Turned...Leave a comment:
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Gotcha!! I understand now. Ok yeah I will 1) try to see if I can spot the spark under no light, and 2) see if I can hear what part is having that noise with that method, thanks!...Leave a comment:
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Thanks! But I got a bit lost on the wooden spoon usage for this...
Could you please elaborate?.
Thanks!!!...Leave a comment:
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That could be, I thought It was a heavy switching noise but it could be arcing. I Will check in full darkness
If so whats the common source of arcing? Bad solder?
And posible solution?
Thanks!!...Leave a comment:
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ok so I should change those smaller ones by the low voltaje side right?
Would that relate to the high temp.at the choppers heatsinls?
Also when the screen has already settled, the chirping sound keeps gong and still 3v present at the fans and peltier output...makes sense?
Thanks...Leave a comment:
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Wine cooler flickers at startup and doesn't cool enough
Hi there!
I have an old wine bottle cooler, it's a basic peltier cell system with a power supply built in with the controller board, with a simple display at the front door and 2 push buttons to select the desired temperatura.
Symptoms are it doesn't barely cool down, and makes a chirping noise at the board.
Both fans on each side of the peltier are (now, after much cleaning) running smooth and silent
When you turn it on, the front 7-segment display flickers for a variable time, usually like 1 minute but sometimes nothing or 3 minutes... Then turn on solid (but still some... -
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.
ThanksLeave a comment:
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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
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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
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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...
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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...
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