Gophert Power Supply and testing led problems

[tmhobadcap]

Today, I found my led light bulb not working and so I replaced it with a new one. Out of curiosity, I opened the damaged one to see what was inside. I saw a series of 16 leds. I have experience in checking the leds strips for using as backlight in tv. Therefore, I would like to do the same to check which led in the bulb is not working. Initially, I set my bench power supply to 3V and 200mA, and test each led. I found that I needed to raise the voltage to 7V so as to make the led to light up dimly. I found one led did not light up, and I think that one has been damaged. When I went to test the next led or the second next one, it was lighted up very brightly. I thought that one was shorted (but when I tested it with a multimeter, it is not shorted) and so I lowered the current of the power supply to 100mA and test again hoping that this will avoid damage to the power supply . I found that led was still lighted up very brightly. Then I further reduced the current of the power supply to 10mA and test again. I got the same result and the power supply is not working after that.

My power supply is Gophert CPS-6005. The maximum output voltage is 60V and maximum current is 5A. It should have over voltage and over current protections according to the manual. Was I not using it properly and so it was damaged? Or was it the power supply problem (not providing current protection)?

Now the power supply output voltage is 0.08V. The setting can change the voltage but after that it will return back to 0.08V. Visually, I cannot see any damaged component. The fuse is also normal. Which component will probably be damaged if I want to fix the power supply?

[sam_sam_sam]

Re: Gophert Power Supply and testing led problems

I personally I do not like computer controlled power supply I find that they have nothing but problems

I personally prefer the manually set ones

That being said do you know if you have a short on the output of this power supply

How you find this out is take a multimeter ( if you have a multimeter ) put the meter leads on the power supply leads and check for a short ( with the meter turn the ohms position) with the power supply unplug from the wall

If you do have a short in the output you need find where it is coming from

One note on some these type of power supply they have a TV diode on the output terminals if this power supply has one check this diode first that this diode has not shorted out

If you can please show a picture of output terminals of this power supply where the power supply wires hook on both ends thanks

Because I want to see if this is one wire for positive and one for negative or does it have two wires on each terminal

Because if has two wires on each terminal then it probably has a voltage feedback circuit

[sam_sam_sam]

Re: Gophert Power Supply and testing led problems

On separate note

On the LED light that you are working what is ic chip number

[tmhobadcap]

Re: Gophert Power Supply and testing led problems

On separate note

On the LED light that you are working what is ic chip number

The markings on the ic chip is EG1000E 8WP3 1749. But I could not find any information from the internet on it.

[tmhobadcap]

Re: Gophert Power Supply and testing led problems

I personally I do not like computer controlled power supply I find that they have nothing but problems

I personally prefer the manually set ones

That being said do you know if you have a short on the output of this power supply

How you find this out is take a multimeter ( if you have a multimeter ) put the meter leads on the power supply leads and check for a short ( with the meter turn the ohms position) with the power supply unplug from the wall

If you do have a short in the output you need find where it is coming from

One note on some these type of power supply they have a TV diode on the output terminals if this power supply has one check this diode first that this diode has not shorted out

If you can please show a picture of output terminals of this power supply where the power supply wires hook on both ends thanks

Because I want to see if this is one wire for positive and one for negative or does it have two wires on each terminal

Because if has two wires on each terminal then it probably has a voltage feedback circuit

When I put the multimeter leads to the outputs and check for resistance, I can see that the resistance is jumping between 0 and about 50 k ohm.

Attached please see the photos for your reference.

[sam_sam_sam]

Re: Gophert Power Supply and testing led problems

When I put the multimeter leads to the outputs and check for resistance, I can see that the resistance is jumping between 0 and about 50 k ohm.

Attached please see the photos for your reference.

“0” ohms really are you sure take your meter if it auto range turn it off and read it again

[sam_sam_sam]

Re: Gophert Power Supply and testing led problems

The markings on the ic chip is EG1000E 8WP3 1749. But I could not find any information from the internet on it.

The link that I might have found safari will not page because it says that it is not secure page

[tmhobadcap]

Re: Gophert Power Supply and testing led problems

“0” ohms really are you sure take your meter if it auto range turn it off and read it again

To be more exact, zero ohm just show up about half a second. Most of the time is jumping between 1 k and 5 k ohms.

[RJARRRPCGP]

Re: Gophert Power Supply and testing led problems

I personally I do not like computer controlled power supply I find that they have nothing but problems

I personally prefer the manually set ones

That being said do you know if you have a short on the output of this power supply

How you find this out is take a multimeter ( if you have a multimeter ) put the meter leads on the power supply leads and check for a short ( with the meter turn the ohms position) with the power supply unplug from the wall

If you do have a short in the output you need find where it is coming from

One note on some these type of power supply they have a TV diode on the output terminals if this power supply has one check this diode first that this diode has not shorted out

If you can please show a picture of output terminals of this power supply where the power supply wires hook on both ends thanks

Because I want to see if this is one wire for positive and one for negative or does it have two wires on each terminal

Because if has two wires on each terminal then it probably has a voltage feedback circuit

Electromechanical, FTW!

[rastar77]

Re: Gophert Power Supply and testing led problems

So i was testing firmware upgrades/fault fix that I made to ksger t12 soldering iron with the power supplied by gophert NPS 1602 at max current limit 3.1A. After some time I noticed 0 current. Now the NPS 1602 has the cc red light on always and constant current limits to 0.0 A.

[rastar77]

Re: Gophert Power Supply and testing led problems

Users of gophert NPS 1602 need to Check the thin output wires and connections!

My issue was caused by factory clamping of a few wires on top of the cable insulation. With supply around 3A current the few copper wires burnt out. As for the CC 'on' operator error...

[captainKKK]

Re: Gophert Power Supply and testing led problems

So, back to the LED bulb. I did the same thing and for each bad LED, I just soldered those over and continued until the next burned out and did the same again and nw there are only 4 working. So I soldered two wires and used the bulb as my inverter to light a strip of leds. The wires put out 57vdc but not much power.