Lexmark x264dn Laser Printer won't power on, Power Supply Delta EADP-100AF CB REV4

[kilobyte256]

Hello I need some help for a Lexmark x264dn Laser Printer. I Plugged it in the mains and immediately the fuse flew at once.

Then I took it apart, i discovered two swollen caps and some burning marks below the bridge rectifier on both sides.

There is also a blown/broken part. It seems to be a tantalum capacitor?

Does someone have have a service manual for this board, or some similar boards. What should I replace besides the swollen caps and broken one. The fuses are intact and I don't see other broken parts.

What is needed to be replaced besides the two caps and the blown part?

What caused the defect of this power supply? Was it the capacitors or what do you suspect?

Thanks for your help.


*Attachments are missing- just a second...
** Attachments added - sorry.

[stj]

Re: Lexmark x264dn Laser Printer won't power on, Power Supply Delta EADP-100AF CB REV

well hopefully the rectifier shorted and killed the cap, or the cap was leaky internally and overloaded the rectifier.
the green thing is an NTC thermister, it limits the current - or it tries till it gets F'd
what's printed on the ntc?

[R_J]

Re: Lexmark x264dn Laser Printer won't power on, Power Supply Delta EADP-100AF CB REV

The NTC1 could be a SCK084. Along with the main filter cap I would replace all 4 small caps in the primary (ie: C66) and the ones around it along with the small swollen one.

[PeteS in CA]

Re: Lexmark x264dn Laser Printer won't power on, Power Supply Delta EADP-100AF CB REV

Concur with stj. Either a leg of the bridge rectifier shorted, killing the cap and blowing the thermistor and fuse, or the cap started going bad, drew excessive current, overheating the bridge rectifier, and blowing the thermistor and fuse.

While you are checking the bridge rectifier and replacing bad parts, check to see if the MOSFET mounted on the heatsink is shorted.

More generally, the power supply appears to be a flyback (or as Delta engineers called it, "ring choke") design in which the "transformer" is a coupled inductor. The "transformer" primary is the filter inductor, hence no filter inductor on the output side. This topology is pretty stressful on output capacitors.

[DerToaster]

Re: Lexmark x264dn Laser Printer won't power on, Power Supply Delta EADP-100AF CB REV

Hello,
I got a similar problem with this power supply. My model is slightly different (EADP-100AF C REV:4 Code:0). In my case the bridge rectifier is dead and I will replace most of the capacitors and the thermistor. By taking out the thermistor, I smashed it completely and cant read the model number anymore.. [picture of leftovers is attached]
The MOSFETs should be fine in my case according to a quick test with the multimeter.

The NTC1 could be a SCK084. Along with the main filter cap I would replace all 4 small caps in the primary (ie: C66) and the ones around it along with the small swollen one.

Thank you for the tipp! Do you think its the SCK084 in my case too?

[DerToaster]

Re: Lexmark x264dn Laser Printer won't power on, Power Supply Delta EADP-100AF CB REV

Just in case.. the attachments seem not to work like I thought. Here is the link to the picture: https://www.badcaps.net/forum/attach...1&d=1618771728

[stj]

Re: Lexmark x264dn Laser Printer won't power on, Power Supply Delta EADP-100AF CB REV

it's probably the same,
delta psu part numbers usually indicate the wattage.
so the power used is the same.

[edis]

Re: Lexmark x264dn Laser Printer won't power on, Power Supply Delta EADP-100AF CB REV

I had big capacitor burning and smoking into PCB. Replaced with 100uF instead of 150uF not available readily, also exchanged two smaller obviously bulged caps. Fuses, rectifier were sane. Not fluent with testing MOSFET, as it did not exhibit properties of semiconductors. Powered on thereafter and voltages on connector were present as per instructions for CN201 in the service manual (J3 found actually). Put into place, printer operates and did pass couple of tests. Thus, caps appear surely stressed and weak points in there, especially big guy.