Hewlett Packard 6200B Power Supply Repair

Cleanup, repair, and upgrade of a Hewlett Packard (HP)6200B pow­er sup­ply.

HP6200B Cover off - top circuit board
HP6200B Cover off — top cir­cuit board with mix of replaced capac­i­tors

My old HP 6200B pow­er sup­ply was start­ing to have prob­lems with exces­sive rip­ple and volt­age reg­u­la­tion prob­lems. I had a good idea of what the prob­lem was before I even opened the case. What I did­n’t expect was all the 4‑terminal elec­trolyt­ic capac­i­tors.
Several of the rec­ti­fied DC fil­ter capac­i­tors were way out of tol­er­ance elec­tri­cal­ly. I removed the 4‑terminal capac­i­tors and replaced them with equiv­a­lent 2‑terminal capac­i­tors along with an axi­al in C10.

HP6200B-PS front circuit board with new capacitors
HP6200B-PS front cir­cuit board with new 2‑terminal capac­i­tor

I quick­ly ran into a prob­lem in that the three neg­a­tive pins con­nect­ed to dif­fer­ent parts of the cir­cuit. The quick and easy way was to jumper the neg­a­tive pads togeth­er to bridge the cir­cuits just as the 4‑terminal capac­i­tors did.
It would work, but I was not entire­ly hap­py with that solu­tion.

I end­ed up with a labor inten­sive, but low cost solu­tion to the prob­lem.

HP 15.5 Rev 1.1 Capacitor board, top/bottom
HP 4‑terminal 15.5 Revision 1.1 Capacitor board, top/bottom

The solu­tion was a small 1″ diam­e­ter print­ed cir­cuit board to adapt the new capac­i­tors to the orig­i­nal 4‑terminal pinout, and allow the new capac­i­tors to be mount­ed in the orig­i­nal alu­minum capac­i­tor shells.
The lead spac­ing on the PCB for the new capac­i­tors is 7.5 mm.

Capacitor 15.5 Assembly angle view
Capacitor 15.5 Assembly angle view
Capacitor 15.5 Assembly bottom view
Capacitor 15.5 Assembly bot­tom view Rev. 1.0
Capacitor 15.5 assembly shell insert
Capacitor 15.5 assem­bly shell insert. Board Rev. 1.0

The new capac­i­tors eas­i­ly fit into the exist­ing alu­minum shell with plen­ty of room to spare.
The two hard­est parts of the process are care­ful­ly open­ing the cans and clean­ing the old capac­i­tor elec­trolyte out so that they can be reused .

HP6200B Front panel with added green LED lighting above meter
HP6200B Front pan­el with added green LED light­ing above meter

I also used this process when work­ing on my HP 6205C dual-out­put pow­er sup­ply.

HP6205C Front panel with green LED's added
HP6205C Front pan­el with green LED’s added above meter

OSH Park Capacitor tri­an­gle adap­tor 15.5 base V1.1

Eagle CAD ZIP file Capacitor155triangle12.zip

3 Replies to “Hewlett Packard 6200B Power Supply Repair”

  1. Great write up. I have the same sup­ply and think i may have bad caps, but i’m not sure. Power sup­ply is only out­putting ~3v at full amper­age when a load is con­nect­ed. Also test­ed in caps in cir­cuit with an ESR meter and it mea­sured low­er than what i would expect on 3 of the 4, could bad caps cause this type of issue?
    Thanks again in advance.

    1. Hi Stephen,
      Bad capac­i­tors can cause all sorts of issues, depend­ing on their fail­ure mode.

      If you decide to replace the caps with two ter­mi­nal ver­sions, ver­i­fy all nec­es­sary neg­a­tive capac­i­tor pins are con­nect­ed.
      On sev­er­al of the caps loca­tions the neg­a­tive pins act as a cir­cuit jumper.

      Another area that can cause mys­te­ri­ous prob­lems is the rotary selec­tor switch.
      I rec­om­mend clean­ing the switch with DeoxIT D5 con­tact clean­er, before any oth­er trou­bleshoot­ing.

      Greg (Barbouri)

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