The Power-Ones that supply power to my MOTM modules are getting older. This HCC15-3A, the largest, has a warranty label of December, 2003.

I thought it was past due to replace the electrolytic capacitors in these supplies. As it turned out, this was a relatively easy task. To make it even easier, I bought a vacuum desoldering iron, a Tenma 21-8240 Vacuum Desoldering Iron, to be precise. Worked great.

Sourcing the capacitors

The capacitors used in the three Power-One models I wanted to recap, HAA15-0.8-A, HBB15-1.5A, and HCC15-3A, have many of the values in common. I went to Mouser and found the same make, capacitance, and voltage ratings for all of them. In fact, each cap is offered in several different series by Nichicon. Not being an EE, I just picked some. Should I have inquired about the series? This is what I bought (Nichicon part number):

• URS1J101MPD1TD 100uf 63V
• UVR2A100MED1TD 10uf 100V
• UMT1H010MCD2 1uf 50V
• URS1V222MHD 2200uf 35V
• UVR1V472MRD6 4700uf 35V
• UVR1V103MRD6 10000uf 35V

All of these capacitors are rated at 2000 hours life. If you enjoy EE reading, feel free to look up information on capacitor lifetime. Whatever the case, these are sure to last longer than if I left the seventeen year old ones in place.

Recapping the HCC15-3A

To get at the board, simply remove the four screws holding the power transistors.

The replacement caps were all generally smaller, either in diameter or height than the originals. Engineering improves! Those large caps were the hardest to remove, because they were cemented down!

One thing that made it easy to do this job was the fact that I could easily remove the supply from the cabinet. Incoming AC connections use sta-con terminals at the power inlet, and the output leads terminate in lugs that fit the MOTM-960 power distribution board.

Recapping the HBB15-1.5A

If you were wondering about the AC power connections, what you see there is the back side of a MOTM-900 or MOTM-950 power supply panel, attached to the back of the cabinet.

More power upgrades to come…

In the next post, I’ll describe upgrading power in the two upper cabinets. These had used two Power-One supplied in each cabinet, a HAA15-0.8-A and a HTAA-16W-A triple voltage supply. These will both be replaced by a new MBB15-1.5-A from SL Power (Condor). Yes, I’m getting rid of +5 volt supplies in the MOTM cabinets.