12v 60A Power supply resistor exploded

Hi, my 12v 60A power supply resistor suddenly exploded after turning on the main switch even though switches for the load connected hasn't been turned on. I would like to ask what caused it to explode.

Well, I am very surprised to hear you have a 12V 60A power supply with only one power supply resistor!

Usually, such devices have quite a number of resistors in them. :roll_eyes:

If we know what it actually was, and which resistor, and a few other details, we might be in a position to help.

In general, you probably need a new one! :grinning:

Power supply, that is. :sunglasses:

It has multiple resistor one of them exploded we tried to jumper it but it exploded again.

Without details, maybe there is a short, or maybe its time has come.

IMG_20200328_135332.jpg

IMG_20200328_135747.jpg

veyy:
It has multiple resistor one of them exploded we tried to jumper it but it exploded again.

As you always expected. :grinning:

OK, I am guessing that is the gate resistor of one of the main switching FETs and that FET has shorted gate to drain. The problem with simply replacing both FETs and the resistor(s) is that you do not know how many other adjacent components are now damaged and that the same failure will occur. In fact you do not know which component failed first to cause the cascade.

zoomkat:
Without details, maybe there is a short, or maybe its time has come.

Oh, there most certainly is a short, and I do think its time has come. :astonished:

Paul__B:
Oh, there most certainly is a short, and I do think its time has come. :astonished:

I have been searching about this for a while,

What is the small yellow taped 4 pin inductish-transformer looking thing near the MKP capacitor?
Is it an 1:1 isolation transformer?

Can bits of aluminum cause it also? I forgot to mention that before turning it on I was drilling at the side for wire slots, I covered it as much as I could but I don't know if some got inside.

veyy:
Can bits of aluminum cause it also? I forgot to mention that before turning it on I was drilling at the side for wire slots, I covered it as much as I could but I don't know if some got inside.

Hmmm, what do you think?

Sound like a very bad idea!

Even if you find a shard of aluminium still shorting some point and remove it, there would be no assurance that you have found or could determine how many components in total are damaged and replace them all.

Some people have expertise in repair of these devices, I do not claim to be one of them and you clearly are not.

Sorry, but safest to replace the poor thing. :roll_eyes:

You can always do a "smoke test" to identify the short location.

I’ve seen similar things happen with the First Robotics groups. They drill the frame to do a last minute fix and the chips short something out... magic smoke is released.

I see the switch mode chip board is toasted. It’s the small green board next to that resistor. The main chip and the transistors are fried beyond recognition. Some of the resistors on there look burnt also.

You might be able to fix it if you get another exact copy and replace all the burnt components, it may be the picture but those large capacitors look like they may be bulging and should be checked.

The large component with yellow tape is a transformer which drops mains voltage down to something your charge pump can use to generate the correct voltage. The smaller transformer may be a choke to reduce line noise.

The damage looks like it’s isolated to the switch mode area...

Again no idea whether it’s worth fixing.

This is what I’m referring to

Hi,
I agree with @wolframore that power supply is toast, that driver PCB is basically cooked and without that functioning properly you will not get it working.

Tom..... :slight_smile: