AAAW!! C'mon .....throw that junk out of the windowAnd the little stupid and cheap meter i use to test capacitors :
regards
Don't know if im being ignorant but.. what or where are the points 1, 2 e and 3 you want to know?
Please confirm
1 is connected to +ve
2 is ground
where does 3 is connected to?
ground or positive?
To Spare some time, i will be putting here answers to the points 1, 2 and 3 in case it's still the same from this image:
Rifaa
Please confirm
1 is connected to +ve
2 is ground
where does 3 is connected to?
ground or positive?
This is a 160w psu, so a 20A fuse should be enough no? or maybe a 15A? And the diode, can't i get a diode for this amps in a motherboard or something? or else i think i have four 6A diodes somwhere, if i joint them they will make a total capacity of 24, that may be enought no? but together they will be about 1/4 of the size of the board heheh, but if needed to work, i will put themOk.. here is the summary.
Looking at the last pic I posted.
1 shows track which is connected to the fuse and it is the incoming +B and through the fuse it goes to the rest of the circuit plus to the diode cathode too. This diodes anode is grounded. ( no. 3 denoted track ) Remember this...if the anode is connected to -B then, this diode is a 16V Zener or mainly for reverse battery connection protection. Either way you can replace it with a normal diode, but this being a DC to DC converter the input current is quite high, say may be around 25Amps for 300W PSU. In this case the fuse will be strong and if a battery connection reversal occurred the diode should have the capacity to blow the fuse.
For this reason the replacement diode must have the surge current capability of around 20 to 30Amps.
But on the other hand If you are careful then you won't need this diode.
You can bridge the broken fuse and replace the +B line with an inline fuse holder of around proper capacity.
what is left now is the burned component.
<internet go figure>
I'll be back
I'm not completely sure, but i think that the fuse never had contact between it's two sides since we started all the testings.The burned component was a bypass capacitor and the one that came off also was the same thing.
Now when I think of it,what happened in the first place.
If you have checked the fuse before and if it was OK then you should not have a problem even though the bypass caps got burned. It will still work provided the PWM is working.
But the diagnosis shows a leaky diode, if so then the fuse will be open, but I cannot see any where that the fuse was checked before hand, am I right.
so, be that as it may. Your supply will be still functional if you bridge the fuse. I don't see any other reason it should not work. It's time to power up.
Leave the diode. Get an inline fuse holder and first use around 2A fuse, just give the 12V to ACC and +B. No load now.
If the fuse does not blow then check the outputs.
You should at least get the standby 5V
Hi again!Put a bridge where the fuse was.
connect the inline fuse to +B.
In other words give the Power through a 2A fuse to +B and ACC, after bridging the fuse with solder.
You'll do just fine. I want you to test it.
see this link , then you'll get an idea
I used a old car battery i have here to emulate the ideal condition on which this psu is used.. on a carIs the supply working without the load, if so explain your connection.
Better yet get a picture
But it's not better to arrange for a diode to put there for security?Good!! you are learning fast.
It's time to rap it up. Get 100nF 50V ceramic cap. and solder it to the diode location.
bridge the fuse with plenty of solder and put a 15A fuse via +B.
Then you are good to go.
BUT BE WISE NOT TO REVERSE THE SUPPLY CONNECTION, now since the diode is not there.
Cheers
I know what you are meaningI doubt that you can get a surface mount diode like the one before.
That is why I said to be careful on reverse connection. The diode is used to blow the fuse if the battery connection is reversed. Now that you know about it I think you will be careful not to be stupid on that matter.
The inline fuse is a better replacement than the soldered one. You can change it without a fuss.
Since getting a surface mount 100nF cap is difficult, I suggested you to get a normal ceramic with a label 104 and put it where the diode was.
Since that capacitor will be bigger than a chip it will be easier for you to solder it on the diode pads. The diode pads are same as the capacitor connections. Which is across +B and -B.
On the other hand, if you can find new surface mount chips then go ahead.
It's all up to you.
Now you know the supply is OK and only the bypass cap fused.
Probably it was an ignition spike.
Another method is to wire a 16V 1W zener across the battery connection.
This will be same as before. It will protect if a spike comes and will short circuit if the supply is reversed.
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