Power Supply Repair - PS2494-YE

[johnau]

I have a power supply ( PS2494-YE REV. C1, D2 ) which was hit by a surge, it damaged a number of components.
I've replaced all the components which were obviously damaged but I am unsure what the value of two are because they are so badly damaged.

I haven't been able to find any docs or schematics on the board so I am unsure the best way to approach working out what they need to be replaced with.

Does anyone have any recommendations?





Components that look the same with different values.

I can't find any reference online to the "P1 E9" which makes it even more difficult to find what one of the damaged ones is.

I assume these are resistors but I haven't seen green ones before.



PS2494-YE REV. C1, D2
IN 220-660VAC, 50/60HZ, 16.0A
OUT 30-600VDC @ 13.2A 8KW

[p.larner]

so where did the surge go to its mains input or the low voltage output,is it a switching supply or linear?

[johnau]

Surge went in the high voltage during a storm.
I wouldn’t be surprised if more is damaged that I can’t see.
I believe it is a linear power supply.

[Swake]

Make it easy and share all info you have else we have to search for it again. (including what you did not find on youtube and that this is a 8kW power supply with 600V on the output)

[Vovk_Z]

I can't find any reference online to the "P1 E9" which makes it even more difficult to find what one of the damaged ones is.

It can be a protective diode. If it isn't shorted I would leave it alone.

[fzabkar]

Can you trace the circuit in that area?

A string of high value resistors would normally be used to sense a high voltage. Is the diode connected in parallel with the resistor at the bottom end of the potential divider? The bottom resistor should connect to the feedback input of the control IC., in which case I expect that this IC would have been clobbered.

[johnau]

Can you trace the circuit in that area?

I have done an overlay trace of the PCB and highlighted the components which died.

A string of high value resistors would normally be used to sense a high voltage. Is the diode connected in parallel with the resistor at the bottom end of the potential divider? The bottom resistor should connect to the feedback input of the control IC., in which case I expect that this IC would have been clobbered.

There is a IGBT GP20B120U-E  IRGP20B120U-E.PDF (113.82 kB - downloaded 46 times.) on the back of the board which popped. This is all connected within the area of the other components which popped.
6x 4006 diodes all gone.
Then there are the two SMDs which I can't identify. I have added a exploded view to the traced PCB on the right marking where they come from.

There are 4 other GP20B120U-E but they are on another board and all seem fine.
It looks like the surge popped these main components after the in coming AC lines and stopped there.

I replaced the 6 diodes which fixed the AC short.

[Swake]

The green smd is very likely just a resistor. It might be a special series such as high precision (1%) or a current surge tolerant version. It is not green in the youtube video (see captured image)

When the power supply is all build up there is the head of a screw in the hole near that green resistor and other component. From another picture (attached) found on the net it is obvious that there must have been a spark that jumped over from that screw to the resistor and the other component. I suggest you isolate the screw with a couple of extra layers of kapton tape. This is a design flaw.

The connection named E2 near the 'diode' is wired, where is it going to? It might help identify what the 'diode' really is or does.

In the left bottom empty corner of the PCB there was a square component which I believe is a bridge rectifier and is connected to the same mains. Please check it out very well too.

[johnau]

Those are some really good shots. Thank you for those and the information.



E2 goes up to another board. Marked bottom left.
It appears to split off in two directions.
Left to the two large resistors.
Right to a cap, which then connects to the small transformer.

E2, E4 and E5 all go to this board with the smaller wires. I am wondering if this is is low voltage for the control circuit.



E7 and E10 also go to the other board but connect directly to the DC out

[johnau]

I managed to get a higher resolution photo of a repaired board from engstok.
The person was so helpful but unfortunately the photo doesn't clearly show the value of one part and they are unsure what the value is.

It still looks like a diode similar to the ones on the other side marked with P1 E9.

[Swake]

Your green resistor seems to be marked as 1001 and this new picture shows 102. That is both times 1k Ohm. That is at least that.

The other component, which might be a diode (likely) or a thyristor (less likely), is marked with ?3?8; That is certainly not the same as the P1EP. It looks like a common SOD-123 package, you might want to measure the size of the package to confirm it is.