Help identify HP Z800 DPS-850DB IC901

[Candymirror]

Hi all,

I have a HP Z800 with a defective PSU Delta DPS-850db (I bought it that way). First I would like to try to repair the PSU, but can't do this without any help.

There's no visible damage, except for a 6 pin IC in to220 housing, the whole front has blown out. Making it impossible to identify the chip. Sadly the blown of part(s) are nowhere to be found.

I'm hoping to find people who would could tell me t what kind of IC, IC901 is, it's mounted on an aluminum cooling bloc next to the 3 large capacitors. The silkscreen say's IC901.

I know there's probably more replacements necessary, but without knowing what kind of IC901 is, there's no reason to take the effort.

Regards,

Ronald

PS. When I've found a place to host a picture, I will attach it.

[stj]

Re: Help identify HP Z800 DPS-850DB IC901

upload the pictures here - we dont like external hosting.
use the "go advanced" button at the bottom.

[Candymirror]

Re: Help identify HP Z800 DPS-850DB IC901

Thank you @stj

It seems to be an ac/dc converter, my best guess would be that it's a Topswitch top242-top250. Maybe I could just place the top250 in place?

Regard Ronald

[Candymirror]

Re: Help identify HP Z800 DPS-850DB IC901

Had some luck, previous owner sent me a message. ic is a top246yn. Also found a defective zener diode markings 7 A3 so-35 0.5W, couldn't find an exact replacement. Going to try a standard 6.8v 1w I happen to have.

[Candymirror]

Re: Help identify HP Z800 DPS-850DB IC901

Finally managed to repair it. The top246yn is responsible for the 5Vsb part of the switch. After replacing the top246yn and defective (shorted) zener, I still hadn't 5Vsb. On the secondairy circuit everything seemed fine. After powering the primary side (after ththe bridge rectifier) with 24V dc it became clear that I had no positive voltage at the transformers primary pin. Tracing back I found a burnt 0.22ohm resistor. You can see it on my second photo, third post. It's between the top246 heatsink and the big Elco, half underneat the blob white hotglue.

[R_J]

Re: Help identify HP Z800 DPS-850DB IC901

That resistor acts like a fuse for the ic, also did you transfer the ferrite bead from the old ic to the new ic (located on the lead of the ic)

[Candymirror]

Re: Help identify HP Z800 DPS-850DB IC901

Yes, I did transfer the ferrite bead from the old top246 to the new. Thoug its more located at the botom near the pcb, instead of the top of its leg. Hope this doesnt mind.