Manson NP-9613

[bianchi77]

Dear Members,
I have an issue with Manson NP-9613,
Everytime the voltage hit 19V, the relay is switching and voltage is going down,
What is the issue ?

Thanks

[CapLeaker]

Re: Manson NP-9613

We need pics to see what you got!
Is it hitting a cc cutoff or what are the testing conditions?

[bianchi77]

Re: Manson NP-9613

We need pics to see what you got!
Is it hitting a cc cutoff or what are the testing conditions?

cc cutoff ?
I got one burn zener diode and replaced it,
could it be TL431 or relay is broken ?

Thanks

[CapLeaker]

Re: Manson NP-9613

looks like there is a bad transistor next where VR8 is written on the board?

[R_J]

Re: Manson NP-9613

The transistor next to CN4 also looks bad, compare that transistor to Q7 and you can see Q7 has the spot along the molding line which is normal but the transistor next to it looks like it is damaged at that point

[bianchi77]

Re: Manson NP-9613

looks like there is a bad transistor next where VR8 is written on the board?

VR8, which transistor ?
Do you mean U2 ? that's TL431

[bianchi77]

Re: Manson NP-9613

The transistor next to CN4 also looks bad, compare that transistor to Q7 and you can see Q7 has the spot along the molding line which is normal but the transistor next to it looks like it is damaged at that point

I can spot CN4, but which one is Q7 ?
I saw it, it's blown isn't ? after zoom ...

[bianchi77]

Re: Manson NP-9613

Have a look on photo please, are these, do you guys mean ?
I'll check, and return to you guys...thanks

[CapLeaker]

Re: Manson NP-9613

Right under that cap. You are on the left of it.

[bianchi77]

Re: Manson NP-9613

Right under that cap. You are on the left of it.

I can't get it, the one on the blue box I'd made ?

[bianchi77]

Re: Manson NP-9613

I've replaced both 2N3904 and TL431, no luck, yet,
could it be a relay issue ? thanks

[bianchi77]

Re: Manson NP-9613

the relay : ,
I got 277 ohm on the coil

[R_J]

Re: Manson NP-9613

I can spot CN4, but which one is Q7 ?
I saw it, it's blown isn't ? after zoom ...

Is that not Q7 marked on the board? so the transistor next to CN4 beside Q7

[bianchi77]

Re: Manson NP-9613

I have replaced both on the blue box, no luck yet ?

[bianchi77]

Re: Manson NP-9613

Could it be this one is the cause ? When I tested ESR=1.5 Ohm Caps = 5400uF, suppose to be 4700uF

[bianchi77]

Re: Manson NP-9613

or it could be an issue withe op-amp 4558

[CapLeaker]

Re: Manson NP-9613

I highly doubt that a 4700uf cap measures 5400uF at 1.5 Ohm ESR. Here is something off with your measuring equipment. IF that 4700uF cap really has 1.5 Ohm ESR, then it would be no good and it would have less capacitance, not more. A good large uF value cap should have something like 0.015uF ESR. An opamp could be at fault too, but right now I think a schematic would be nice.
I also think, that you are focused on the relay turning the power off and the relay is not supposed to click. I think that is wrong and the relay is supposed to click, but the PSU is not delivering power for higher voltages. You can go to any of these CV CC PSU's and they will click not only once if you go from Zero Volts to 30V.
Could it be the relay? Yes, we know it clicks, so it does get voltage and the coil is good. So how could it be still bad then? If the contacts inside the relay are burnt off. Take the relay out and test all the contacts on the relay powered up and no power, cording to the spec sheet.

[bianchi77]

Re: Manson NP-9613

I suspect, it's 4558 op amp, I did an experiment with new LM 358, it is doing the same voltage drop...

[R_J]

Re: Manson NP-9613

I have replaced both on the blue box, no luck yet ?

Was the transistor and ic shorted? If they were, check the components that connect to them, if they are indeed bad, someting connected to the also is bad
Was the Zener diode you replaced marked on the board ZD2? and connected to the U2 tl431
Was the zener a 5.6v by chance, if it was, is there a resistor marked R19 (750Ω) connected between ZD2 anode and C9 negative?

[bianchi77]

Re: Manson NP-9613

Was the transistor and ic shorted? If they were, check the components that connect to them, if they are indeed bad, someting connected to the also is bad
Was the Zener diode you replaced marked on the board ZD2? and connected to the U2 tl431
Was the zener a 5.6v by chance, if it was, is there a resistor marked R19 (750Ω) connected between ZD2 anode and C9 negative?

I replaced ZD1 12V 1W....and TL431