Help repairing IBM PS/2 L40 SX docking station

[markgm]

I have a docking station (PSP I (Portable Service Platform)) for an IBM PS/2 L40 SX that I’m trying to restore. When powering it on the laptop gets power, but the docking station itself doesn’t. I thought the issue was with the power supply (there are two, one for the laptop voltage, and one for the docking station), so I rebuilt the PSU for the docking station, but the docking station still doesn’t get power. I found a replacement power supply for cheap so I picked that up, but there’s no change. Realizing I have another issue, I started probing the docking station and realized that there is a problem on the board as the power supply isn't putting out the proper voltage when the power supply is connected to the board, but the power supply puts out the proper voltage with it's not connected.

There aren’t a lot of components on the board, but I do see 8 tantalum capacitors, and I wonder if they could be the problem. I can’t find replacements for these: 6 are marked 5615 372 9045 (4 pins, -++-), 1 is 89453, and 1 is 9422. Can anyone point me in the right direction for an alternative part?

Once I find them the next hurdle will be installing them, this doesn’t look to be an easily serviceable part!

 

[NeXT]

First sanity check is seeing if any of the tantalums are shorted. They don't always go bang with low current power sources. I had an Apple IIe memory card that would kill the IIe until I pulled about half a dozen tants off the board and the 5v short to ground went away.

 

[markgm]

First sanity check is seeing if any of the tantalums are shorted. They don't always go bang with low current power sources. I had an Apple IIe memory card that would kill the IIe until I pulled about half a dozen tants off the board and the 5v short to ground went away.

It seems like only one of them has a short. The bigger issue is what to replace it with. I can't find any information on these tantalum capacitors.

 

[orchidsound]

IBM 5615372 tantalum capacitors

IBM 5615372 tantalum capacitors

It seems like only one of them has a short. The bigger issue is what to replace it with. I can't find any information on these tantalum capacitors.

Did you ever get this solved? I have a bag of 5615372 tantalum caps (4 lead) from IBM.

 

[markgm]

Hi, I removed the offending capacitor and the docking station came to life, though I'd feel better replacing it since I assume it was put there for a reason!

 

[bear]

I just pulled a shorted one off an 0665-53 fixed disk drive. I wasn't sure what to make of the markings, either, so I pulled another one off that wasn't shorted out and measured it. It appears to be 20µF. I measured a second one just to be sure, since I can't see how "5615 372" could be read as 20µF, but it absolutely seems to be.

I replaced it with a pair of 10µF (2 10µF capacitors in parallel make 20µF) 16v (since it was in parallel with the 5v power rail) tantalums, positive leads to center pads. Seems to be doing the trick, at least as far as I can tell. The drive is in bad shape and working very poorly, but I'm confident that has nothing to do with my repair.