Fixing/Replacing bad transformer in logic analyzer SMPS.

[vk6zgo]

OK,bearing in mind HackedFridgeMagnet's wise words of caution,reconnect the bridge,but with nothing connected to its output.
Apply power & see if the fuse still blows.
If it does,you need to replace the bridge before you go any further.
If not,slowly reconnect components until you blow the fuse again,keeping in mind that you do the reconnecting with the power off!

NOTE: If you get the rectifier going with its big Electrolytic capacitors in circuit,& no other components,you must after turning off & unplugging the mains,make sure that the capacitors are discharged before touching /reattaching anything!

For a 230v  AC input,the caps can be charged to around 325 v DC!
You REALLY don't want to get across that!

[CampKohler]

First thing, get the manual http://www.hp1652bmanual.com/. Then find out the voltages the supply must furnish. If you can live with external surplus supplies, maybe you could do that until such time as you get the OEM supply repaired. There is another thread on the forum about a similar instrument. Perhaps you can communicate with the author for some help.

If everything works on external supplies, you can measure the load currents and then build a dummy load for the OEM supply to aid in troubleshooting it. At least if something goes terribly wrong it won't wipe out the instrument itself.

If there is overheating of a transformer, there should be a corresponding smell. Start sniffing after you power down, perhaps with the aid of a straw as an extension of your nose.