Hello, I don't have much luck with Power supplies working for me. So working with a 32V 5amp that has been really nice to me in the last month. However it seems that something isn't working and I wonder if it is the main chip or something in between. This is based on the XL4015E1 chip.

So what I did was try and connect a external Volt/Amp meter to be able to run some testing over the meter that is already on this unit. I know the AMP meter on the unit isn't working at true value. So I took this other meter and connected it to the output of the PSU and it didn't do anything other then drop in volts on the units output display and the meter that came on for a very short second went dark. (First thought was I lost the meter I was connecting) however looking at the meter on the unit it was going down in volts ending at 0. I took the meter off and it went to 0.48v However any load goes to 0.

So I am wondering if the chip has gone. or if there is something I should look over besides the 4015 chip?

It has 2 LM358 chips, a XL4015E1, STM8S00E 8bit MCU and A79T. It has a Few SS54 Schottky Rectifiers.

So I don't know what things should read on the chip however the Vin shows the 19.5v from the supply VC 13.01v SW shows .61 with no load and 0 with a load. FB 0.02 and GND 000

Now as it was stated before it went to 0.48v when it was set for 12.9V before all went up. I can turn the V adj with little gain only to 0.61v Any idea where to look? Sorry I don't have a Diagram for this PSU as I didn't make it and I am not that good at trying to draw off a PCB.

Any ideas of what I should test or does it sound like the XL4015 has given up?

James

 

I think you blew your PSU.

Check your PSU with a DMM.
You connected an Ammeter across a PSU and if your PSU do not have protection or fuse it will fail.

 

Thank you for the Reply. I have checked it with a DVOM and it does read as the Display on the unit says. .61 without load and 0 with a load. It does have protection some where. I have used it to inject volts into a circuit to find an area of a dead short.

What I don't understand is there was nothing to say this should have failed. It didn't spark. It wasn't connected backwards. I took the meter and connected it to different unit build based on the LM2596 and it didn't have any issues and connected as it was to this one.

I guess I will call it and replace the chip. It has been really good to me in the last month while working on other projects. Plus it has been my phone charger this last month when it isn't being used for other things the USB output has been very nice over the normal charger.

I wish it was as easy as something different in the circuit.

What I don't understand is the voltage on the chip? I understand the Vin. However VC is close to where it was set before it went bad. There is nothing on the unit that reflects this value. The SW only shows what the output is now unless I put a load then shows 0 and FB is almost 0 with a 0.02 and from what I know should regulate off a 1.25v threshold.

Again thank you for the Reply Guess I will order some so I have backup.
James