AcBel API0PO13 does not power on. Fan spins a bit then stops.

[sententia]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

The mains cap is a 120μf 450v..

About the 5vsb. There are two purple cables going in to each connector. One does give 5v the other 0v. Both are connected to pcb via a connector located at the corner (last photo of first post)

I haven't measure voltages before after mains capacitor as i don't feel very confortable working on live pcb yet.

Do you think there might be a problem on the primary side?

P.S. I might have damaged the pcb trying to remove switchmode diodes (before buying the correct iron tip), as i short now one of the three green wires which to kick the fan but no go...

Do you have the 5vsb?
What is the voltage rating of the mains cap?
What voltage do you have across the mains cap at:
1) Standby?
2) On?
T

[Toasty]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

As this seems to not be a computer PSU, rather an ATM or some such banking device, the voltages and methods it uses to turn on are unclear. In other words, it may need a signal from whatever it powers to turn on some of the other voltages.

Wincor Nixdorf - WN P/N: 01750043987

3.4 volt is not typical; 3.3v is.

24v is not typical except in industrial controls and Apple products.

-5v is not typical, but the -12v was, back in the ATX time period.

A shame that you damaged the board. If you can correct the damage, then perhaps we can go through this diagnosis.

Schematic and/or information as to the device this powered may provide clues to the method of operation.

Yes, I think it might be a primary side issue. At the least, it could be a PFC issue. Without voltage readings, it is not possible to be sure. With 220vac mains you should have ~312vdc across the cap at Standby and ~385vdc when On.

The 9v max on the 12v line is kind of a giveaway that the PFC is not working.

T

[sententia]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

As this seems to not be a computer PSU, rather an ATM or some such banking device, the voltages and methods it uses to turn on are unclear. In other words, it may need a signal from whatever it powers to turn on some of the other voltages.
Wincor Nixdorf - WN P/N: 01750043987
3.4 volt is not typical; 3.3v is.
24v is not typical except in industrial controls and Apple products.
-5v is not typical, but the -12v was, back in the ATX time period.
A shame that you damaged the board. If you can correct the damage, then perhaps we can go through this diagnosis.
Schematic and/or information as to the device this powered may provide clues to the method of operation.
Yes, I think it might be a primary side issue. At the least, it could be a PFC issue. Without voltage readings, it is not possible to be sure. With 220vac mains you should have ~312vdc across the cap at Standby and ~385vdc when On.
The 9v max on the 12v line is kind of a giveaway that the PFC is not working.
T

As i mentioned this PSU comes from a wincor POS (point of sales) system. Just for the record it is a BEETLE /M (i attached some pics) that uses pentium /celeron s478 cpus... The 24v rail is used for the recpeipt printer...

I found another similar psu that is actually working. What i found by coincidence is that the psu turns on with another green wire than the one i used (the one on the plug that has 12v 5v and 3.4v rails)! So i went today and installed in the machine and everything works fine. I tried that on the psu that this thread refers to and it has the same symptoms as before, fan spins a bit than it stops. So i must have been wrong. I suppose no damage to pcb after all...

I have attached some images from primary side, if that helps, with what i believe to be the pfc. I also noticed on the good psu that the mains capacitor is not bulged at all and is totally flat. I thought that does not matter as ALL the working psus i have opened seem to have bulged mains capacitors without a problem. Anyway i expect a ers capacitance meter to arrive soon so i will be able to test that also.

By the way i can't find schematic anywhere...

Thank you very much for the input!

P.S. I forgot to note outputs and cable colors of the working psu.. clumsy me..

[Toasty]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

Yeah, missed that on the first post.
Perhaps if it was noted as Wincor POS I would have caught it more readily. Age.

The ML4800CP is the PFC controller and that daughterboard is it's supporting circuitry.

I'd replace (from experience) the small cap on the main board right in front of it and see what happens.

T

[ben7]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

I first have to thank you for the good pictures you provide. I'm tellin ye, they help a lot!

About the 'bulged' capacitor ... it likely isn't bulged. Those plastic caps on top quite often warp from heat (regular temps, not overheating temps!). press down on it, if the capacitor isn't bulged then it should squash inwards. If it feels like something is under it, then you can cut the plastic disc off to see underneath. The plastic disc is there to help with insulation from other stuff, as the capacitor can could be at a high voltage potential, being on the primary side (mains voltage in this case) of the PSU.

[sententia]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

I first have to thank you for the good pictures you provide. I'm tellin ye, they help a lot!

About the 'bulged' capacitor ... it likely isn't bulged. Those plastic caps on top quite often warp from heat (regular temps, not overheating temps!). press down on it, if the capacitor isn't bulged then it should squash inwards. If it feels like something is under it, then you can cut the plastic disc off to see underneath. The plastic disc is there to help with insulation from other stuff, as the capacitor can could be at a high voltage potential, being on the primary side (mains voltage in this case) of the PSU.

Thanks about the pictures...! I hoped they would help!

You are right about the capacitor... it is just the plastic swollen, underneath feels empty ...

[sententia]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

Yeah, missed that on the first post.
Perhaps if it was noted as Wincor POS I would have caught it more readily. Age.
T

No worries.... i just mentioned it to give some more detailed info about the POS!

The ML4800CP is the PFC controller and that daughterboard is it's supporting circuitry.
I'd replace (from experience) the small cap on the main board right in front of it and see what happens.
T

I removed the capacitor from the main pcb, as i couldn't read it, and it is a 68μf 25v. Unfortunately i don't have a replacement to test it.. I really hope my esr meter arrives soon....

[Behemot]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

I have some feeling that if primary caps go bad, than it's like in this case Being on high voltage, quite often strange things (lightning, explostions) happen…

[Toasty]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

...I removed the capacitor from the main pcb, as i couldn't read it, and it is a 68μf 25v. Unfortunately i don't have a replacement to test it...

Nothing close? Anything from 47 to 100µf @ 25/35/50v will work for testing.

T

[sententia]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

Nothing close? Anything from 47 to 100µf @ 25/35/50v will work for testing.

T

I had some 47μf caps so i tried with one and two in parralel but no joy....

It feels a difficult catch really...

[Escort Eagle]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

Sententia, Is it creating heavy load on your brain !!! PSU SMPS is one of the most difficult SMPS which forms all kind of critical problem found other than any SMPS circuits !!

Let me clear your problem Fan spins a bit then stops That means - Your controller IC is detecting an Absence one of your Output voltage . This is why controller IC is telling PSU to keep shutdown . Now find which Output voltage is remaining Absent to the Controller IC .

I want to share one of my experience with you - Few years ago I got a PSU from a customer which Fan spins a little bit and then stops !! After searching for several hours in secondary and primary side, I found nothing problem !! You will be surprised to hear that what was the problem there !! Can you think what was the problem there ?? At the end I found that The Fan was Bad itself !! This why Controller IC was shutting down the PSU .

I will suggest you to check this FAN with other PSU or with a 12V supply .

[sententia]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

I know that it is giving me a hard time.... i also know that my knowledge is very basic about all the parts of the PSU which makes think more difficult. Anyway do know that the psu has sensors on the voltage rails... My mistake was that when i found out i had a identical working psu (so now i do not need the current one... i try to save it for educational purposes and to have a spare one) i didn't take a note from the pin voltages in order to check the one i have now... The only thing i remember is that the pinout cable colors do not follow the atx logic... I found that on the second connection jack the grey wire was -5v (if i remember correctly) etc..

About the fan now.... Funny or not i also suspected, although a long shot, that it may be a fan problem.. However the fan when connected to power source spins excellent... I have not tested is if there is a problem with the fans sensor (yellow wire).

[sententia]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

Just tested on the pc ... sensor is ok.

[sententia]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

Just measured again resistances to ground.
3.4v gives 15ohm (does this sound correct?)
5v rises and stops at 202ohm
12v rises up to 5k after some time drops to 0ohms (multi at 20k), on multi 2k it goes up to 1.8k.

Where the 3.4v rail is connected to the pcb there is a 0.01ohm resistor but i cant understand where the other pins goes. Seems to connect to an inductor and possible some capacitors but i am not sure!

It seems that the 3.4v rail has different behavior the the others. If that help anyone for some direction....

[sententia]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

I started disassembling the psu as i am running out of hope ....
So here are so more pics. Does anyone know what the green capacitor like part is? (TCJ 103)

Possibly a newbie question but ... do you know if the smps transformers can be used as regular ones on 50hz ac? I have done some research but haven't come to a conclusion....

Thanks!

[Behemot]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

Thermistor, likely for fan regulation.

Generally, no. They have much lower inductance, will act like conductor (short) for 50 Hz.

[sententia]

Re: AcBel API0PO13 does not power on. Fan spins a bit then stops.

Yeah, missed that on the first post.
Perhaps if it was noted as Wincor POS I would have caught it more readily. Age.

The ML4800CP is the PFC controller and that daughterboard is it's supporting circuitry.

I'd replace (from experience) the small cap on the main board right in front of it and see what happens.

T

After removing and testing many many parts from the PSU i came across to the first definite suspect of the problem. The little capacitor right next to ML4800CP on the daughterboard has about 70 - 80 ohms ESR. Toasty suggested to test the one on the front on the main pcb. I didn't check the small one next to the ic because i didn't have the esr tester nor a replacement at that time. The capacitor is a 3.3uf 50V.

I can't really test the psu as i have destroyed a couple of parts on the pcb however if someone meets the same problem i strongly suggest to check that little capacitor as PSU didn't have many working hours and ALL other parts, especially rail capacitors tested like new.

I tested the cap because of a problem i came across on a different psu which was solved by changing a couple of capacitors in the PWM circuit.

P.S. Can i use any of the sub circuits to "be" anything by itself ? especially the small board with the transformer on it? The transistor is a power fet IRFBC20 and the small ic on the bottom side is a TL431. Thank you.

Best regards.