Perseus repair

Home Up Perseus repair hm5033 Anritsu Cell Master HP8566b hp8672a hp8970a HP8970b error18

My remote Perseus receiver was no longer working
When I logged in to the remote computer I could see that the Perseus hardware was no longer
communicating to the computer and the USB connection showed a failure which I did not understand.

A few weeks later I was at my remote site and tried to find the problem.

I noticed that the led's on the Perseus front panel were a bit weak and even seemed to flicker.
After several attempt I concluded I could not fix the problem at the remote QTH and
decided to take the system back home to investigate the problem.

At home I first measured the power supply and found this one was failing.
It should have 5 Volt output but in this case it was only showing 2.6 Volt.

I then first tested the Perseus hardware using another power supply and this responded normally.

It was clear that the Perseus power supply was causing the failure.


I opened the power supply and found that there were four capacitors, two for the high voltage part and two for the low voltage part.
I guessed that these capacitors most probably would be the cause for the failure.

I unsoldered the low voltage capacitor and measured the capacity and ESR value.
The capacity was a bit reduced but the ESR value was almost 0.9 ohm. I guessed this ESR was too high and replaced the capacitor by an other capacirot with an ESR of 0,1 ohm. I measured the power output and it was at 5,2 Volt.


The power supply with the first new capacitor
the one most right below (Blue)



After that I also unsoldered the second low voltage capacitor which showed an ESR of 1.9 Ohm.

I also replaced this one for a new capacitor and than I tested the power supply on the Perseus hardware and it was working fine again.

The new capacitors were a bit larger than the old ones so I had to make a small modification on the housing
 to get all into the housing off the power supply.


After all the repair was not to bad, and as with many switched mode power supplies
it was caused by bad capacitors having a too high ESR value.