Hello all.
First - please excuse my bad English.
I am going to share my experience to restore defective HP8593A Power Supply
(PS). Nothing useful found in the net...except: you
can send PS for repair or buy another one from Ebay.Not reasonable for me,
so I decide to repair my self.
Looking today at mine notes I see I could write more details, but it is
late...PS already repaired, assembled and installed.
During time of repair I had no idea my experience can be shared with you...I
was very depressed/worried to return my SA to live.
Will send today pdf file in Files area with my personal hand made schematics
and pictures about this named HP8593A Power Supply repair. I believe
information there could be helpful for some of you.
Some notes:
1. Original manufacturer: MICRO Energy INC p/n 10-0060 , HP p/n 0950-1977
2. Due hand made schematics drawn from PCB's it is possible to have
errors.Schematics are partial for control part of PS and
pictures are not very good.
3. Pinout's of PS J13 DB37 connector:
+15V - 1,2,3,20,21,22
- 15V - 4,5,6,23,24,25
+ 5V - 9,10,11,12,28,29,30,31
+12V - 13,32
Fan - 7
Analog GND - 7,26,27
Digital GND - 14,15,16,17,33,34,35,36
LINE_TRIG - 18
HPWRUP - 37
LPWRON - 19
4. PS has standby power supply designed by UC3842 and P2N85 producing +18V
and *always ON.*
5. To switch PS ON connect pin 19 (J13) to GND.
6. PS need minimum 50% of nominal load current of any voltage to produce
correct +5.2V.
7. Not clear for me how +5.2V regulator works.For what is transistor TIP30C
?
*8. When two PCB's are removed from box you have to connect four GND points
with additional wires during repair time.
See diagram.* *Two parts of metal box are used as GND wire. Due this
all PCB screw have to be installed and well
tighten when you finish repair.*
9. When assembly PS after repair be careful with:
- one of six screw for mounting of radiator is *shorter! *See drawing.
- remember how connector DB37 was. It must be uppermost when assembly
back. See drawing.
Feel free to ask for questions and good luck !
Regards and 73
Roumen / LZ3RV
