Enermax Platimax

[madan1]

Hello everyone.

I have an Enermax Platimax EPM1500EGT which does not work. On several occasions it started, but I have no idea why.
Currently it is dead.
I'm not familiar with troubleshooting pc psu and have just basic idea about the design and how they work.
I checked the standard things - caps are OK, switching trans. also seems to be OK, the rectifier seems fine...
Also that unit is so overpacked that most of the components are unreachable from the top side.
So any ideas how proceed from here?

[sam_sam_sam]

Re: Enermax Platimax

Hello everyone.

I have an Enermax Platimax EPM1500EGT which does not work. On several occasions it started, but I have no idea why.
Currently it is dead.
I'm not familiar with troubleshooting pc psu and have just basic idea about the design and how they work.
I checked the standard things - caps are OK, switching trans. also seems to be OK, the rectifier seems fine...
Also that unit is so overpacked that most of the components are unreachable from the top side.
So any ideas how proceed from here?

Look and see if you can find a switching regulator ic chip when you find that ic chip look for a small UF value near that chip there might be more than one of them replace them

Unless you check the caps with a ESR capacitor checker you will not know if the capacitor is good or not when I check capacitors with a ESR meter I compare the results with a NEW capacitor

( if I get a reading of more than 2% difference in ESR value I replace them)

of same UF value and voltage but the voltage marked on capacitor is not the determining factor in the ESR value as such

If after you replace those cap or caps and power supply still does not want to come ON then check the voltage on the three big filtering caps that are together
be careful when measuring the the voltage on these caps

Report the voltages that you get on those caps

[madan1]

Re: Enermax Platimax

Look and see if you can find a switching regulator ic chip when you find that ic chip look for a small UF value near that chip there might be more than one of them replace them

Unless you check the caps with a ESR capacitor checker you will not know if the capacitor is good or not when I check capacitors with a ESR meter I compare the results with a NEW capacitor

( if I get a reading of more than 2% difference in ESR value I replace them)

of same UF value and voltage but the voltage marked on capacitor is not the determining factor in the ESR value as such

Found and tested - 10.++ uF/ ~0.4 ESR ( labeled as 10uF/5V ). The new ones which I have in stock ( 10uf/100V ) show ESR between 1.2 and 2.0, so I guess it is fine?

[sam_sam_sam]

Re: Enermax Platimax

Found and tested - 10.++ uF/ ~0.4 ESR ( labeled as 10uF/5V ). The new ones which I have in stock ( 10uf/100V ) show ESR between 1.2 and 2.0, so I guess it is fine?

If that is the case

Ok so if you assume that the two capacitors are good then the switching regulator is is probably bad

But—>

What is the voltage on the three main capacitor

[madan1]

Re: Enermax Platimax

the switching controller is the right IC on the vertical board next to the main transistors ( https://www.badcaps.net/forum/attach...1&d=1545383994 ). Next to the board is the cap which I believe is the one you are talking about.
I also tested the two caps which you have pointed on the other side, and they both are good.
All 3 main caps read 29x uF ( roughly -10% of their original 330uF capacitance ). Their voltage was something like ~300v ( I can't remember the exact value, but it was what was expected ).
Other thing - from the switching IC datasheet vcc ( 5-18V ) is expected, but currently is missing. Indeed, there is no significant ( >0.5V, probably some static or em noise ) voltage on any of the vertical switching board pins.
Also, no stand-by voltage on the motherboard connector.
The damn thing is so overpacked, that without disassembling or service manual, there is no way to know what is hidden under all that big components and heatsinks. Now I know why several repair shops refused even to take a look at it before it was given to me by a friend.
I'll give it several more tries and then I'll just scrap it for components.

Happy holidays, by the way .

[R_J]

Re: Enermax Platimax

And the switching ic is a ....?

[sam_sam_sam]

Re: Enermax Platimax

And the switching ic is a ....?

I second this what is the part number of the switching regulator ic chip

Take a close up photo of the area around the switching regulator ic chip and the bottom of the board in the same area

Thanks

[Stefan Payne]

Re: Enermax Platimax

Better Pics.

https://www.techpowerup.com/reviews/...1200EWT/4.html

Maybe UCC28950??

[madan1]

Re: Enermax Platimax

Here are the photos

[madan1]

Re: Enermax Platimax

If that is the case

Ok so if you assume that the two capacitors are good then the switching regulator is is probably bad

But—>

What is the voltage on the three main capacitor

Well, now I see that there are several switching ICs.. and I've been focusing on the one controlling the 4 main transistors.
Another one is the one you pointed out - TOP267EG on the opposite side of the board. So I guess this is for the standby circuit?
Anyway, last time I desoldered the two el. caps, measured them and did not notice any issues.

[sam_sam_sam]

Re: Enermax Platimax

Well, now I see that there are several switching ICs.. and I've been focusing on the one controlling the 4 main transistors.

What is the part number of the other switching regular IC chip

[madan1]

Re: Enermax Platimax

What is the part number of the other switching regular IC chip

that's the primary


2PCS02 - https://cdn.badcaps-static.com/pdfs/...a3ccc3b9a3.pdf



here is the one next to the 2 caps
TOP267EG




I can't find what this IC is... it is right next to the switching board and under the heatsink:

[sam_sam_sam]

Re: Enermax Platimax

I can't find what this IC is... it is right next to the switching board and under the heatsink:

Here is the data sheet for this device

https://cdn.badcaps-static.com/pdfs/...c907c22d05.pdf

[sam_sam_sam]

Re: Enermax Platimax

Can someone please explain just what this chip is suppose to do and how it works

The data sheet is very vague about what this chip is

CM03X

https://cdn.badcaps-static.com/pdfs/...c907c22d05.pdf

[sam_sam_sam]

Re: Enermax Platimax

I'll give it several more tries and then I'll just scrap it for components.

Happy holidays, by the way .

When you are going to scrap it let me know I would be interested in this power supply

[momaka]

Re: Enermax Platimax

Let's try a different approach here.

First, I always start with the stand-by circuit. With the PSU plugged in the wall, do you get 5V on the 5VSB line? If yes, measure the voltage on pin PS_ON at the ATX connector. What do you get? After this, try jumpering PS-ON to ground to start the PSU. Note that some PSUs won't start without a load. If that's the case, use some 12V car light bulbs on the 5V and 12V rails as a load. 2 to 3 bulbs (20-50W) on each of these rails should work nicely as a load. If the PSU still doesn't turn On, see if you can run this same test with the PSU PCB outside of its case (BE CAREFUL! High voltages on the heatsinks) and measure the voltage across the big capacitor(s) on the primary side. Being that they are rated for 400V, I expect to see 375-385V when the PSU tries to run/turn On (i.e. when the PS_ON is jumpered to ground.) Otherwise, with the PSU only plugged in the wall but not made to turn on, I expect those big caps should have around 340V. Let us know what you find from the above tests I suggested. Hopefully, that should give us a direction to go.

[madan1]

Re: Enermax Platimax

When you are going to scrap it let me know I would be interested in this power supply

Well, the process already started - a colleague already snatched the fan .
The psu has been lying around for months and I work on it only when there is absolutely nothing else for fixing .

[madan1]

Re: Enermax Platimax

Let's try a different approach here.

First, I always start with the stand-by circuit. With the PSU plugged in the wall, do you get 5V on the 5VSB line? If yes, measure the voltage on pin PS_ON at the ATX connector. What do you get? After this, try jumpering PS-ON to ground to start the PSU. Note that some PSUs won't start without a load. If that's the case, use some 12V car light bulbs on the 5V and 12V rails as a load. 2 to 3 bulbs (20-50W) on each of these rails should work nicely as a load. If the PSU still doesn't turn On, see if you can run this same test with the PSU PCB outside of its case (BE CAREFUL! High voltages on the heatsinks) and measure the voltage across the big capacitor(s) on the primary side. Being that they are rated for 400V, I expect to see 375-385V when the PSU tries to run/turn On (i.e. when the PS_ON is jumpered to ground.) Otherwise, with the PSU only plugged in the wall but not made to turn on, I expect those big caps should have around 340V. Let us know what you find from the above tests I suggested. Hopefully, that should give us a direction to go.

Thanks for the reply.
On the main caps there are 340V ( or was it 370.. I promise next time to write it down ) when connected to the power line.
I soldered 0.5meg resistor to them and now at least those discharge in few minutes after disconnected from the mains and can continue with the component testing.
I wasn't aware that the heatsinks are live, but suspected it, thus work on this as if the whole.. "thing" is live ( really not comfortable with working on high V, especially without the schematics ).
I remember this PSU used to start from time to time even without any load. Then it stuck in "boot loop" and now it's just dead.
I have absolutely nothing on the cables - no standby V, no PW_ON.. nada.
I also do not see any changes when PW_on is grounded.
The only V which I'm able to seeexcept for the big caps is about 1.7 on the optocoupler next to the vertical switching board ( no true RMS DMM ). All other optoC show nothing on either side.

By the way, which is the stand-by circuit? Do you think it is the TOP267EG or other IC connected to one or both small transformers on the other side?
On the lowV side next to the TOP267EG transformer there is no V on the filtering capacitors ( next to the TO220 diode ).

Any idea what voltage is expected on the transformer coils? As I mentioned - I do not have a true rms dmm and wonder if my dyo scope can be used without losing its magic smoke...

[madan1]

Re: Enermax Platimax

Happy new year - as I promised here is the V on the main caps - 320-322V.

I dissembled the connector panel and got some more space on the secondary side. The +5stndby is the TOP267EG and the transformed next to it. On the secondary side, there isn't anything "smart" controlling the +5V.. just a half-wave rectifier and some filtering.
I have the 320V on the Drain-Source of the TOP267EG but it just does not switch.
So I keep digging.
By the way, enermax told my to go ....... cause they do not provide service manuals to the end customers.

[RJARRRPCGP]

Re: Enermax Platimax

By the way, enermax told my to go ....... cause they do not provide service manuals to the end customers.

Reminds me of what some central fire alarm panel companies would do, especially now! At least a couple of them, love to act like they're a space station control system!