HP 5061-3476: Which boards go where

Chris Zach cz at alembic.crystel.com
Fri Sep 10 22:47:13 CDT 2021

Further review: Looking at photo IMG_6081.jpg it shows the layouts of 
the boards. Specifically A1 is the pre-regulator board pn 5061-3457 
which is the one with the caps and A2 is Inverter board PN 5061-3454.

I think if your PS doesn't work one problem is these boards are 
backwards. Don't know if that will blow up your supply but interesting 
to note...

Hm.... From what I can see it looks like the 120 goes into a transformer 
on the bulkhead and is stepped down to 24 volts DC which then feeds 
"stuff". I'll start there and see if I get 24dc at the first stage, 
which should then be filtered by the caps and sent on to the various 


On 9/10/2021 11:41 PM, Chris Zach via cctalk wrote:
> Hi Guy!
> Thanks for the post and interesting. No it's not quite the exact power 
> supply but close. However....
> Are you *sure* those cards are in the right slots?
> Reason I am asking: When I look at the HP docs they label the 
> Pre-regulator board as A3A1. A3A1 also has the red LED. The inverter 
> board (the one with the transistors and transformers) is A3A2. Likewise 
> the battery charge boards are A3A3, A3A4, and the control board at the 
> end is A3A5.
> The slots are labeled 1-5 with 1 being closest to the power cord and 5 
> being on the output end. A3A5 will only fit in slot 5, and A3A4 has the 
> 12 volt trim pot that is accessible outside the supply by a cut-out so 
> it has to be in slot 4. Slot 3 is not used on my unit because I don't 
> have the battery backup circuits.
> However in your picture slot 2 has the LED preregulator board and slot 1 
> has the one with the transistors and transformers (inverter). So either 
> your picture has the parts backwards or someone at HP should go to hell 
> for exceptionally bad numbering.
> Does your supply work?
> C
> On 9/10/2021 12:43 PM, Guy Dunphy wrote:
>> Here are some disassembly pics of a HP 5061-6615 power supply.
>>    http://everist.org/pics/hp1000_ps/5061-6615.zip     2.9M
>> Details:
>> HP 1000 Model 2113E  SN 2340A03701  OPT 004  014
>> power supply  Model 5061-6615    SN 2340
>> Not the exact same PS as yours, but it might help?
>> My problem is I haven't been able to find a manual and schematics for 
>> that
>> apparently late model supply. Though last time I looked was years ago.
>> The lack of a manual/schematics froze that restoration project.
>> Can anyone suggest where I might find a copy?
>> PDF, or I'd pay for an original paper copy. (To use, and also ensure it's
>> scanned in high quality.)
>> Guy
>> At 09:30 PM 9/09/2021 -0400, you wrote:
>>> Quick question: I've been cleaning out and repairing an HP5061 supply
>>> for a 1000 computer. However I didn't take a picture of the 4 boards
>>> when I pulled them and I want to make sure they go in the right places.
>>>  From the manual (page 99 of 92851-90001_Sections-IXB_Mar-1981.pdf) the
>>> slots are labeled A6-J1 through A6-J5. Does this mean that:
>>> J1 is the
>>> J5 is the control board (A3A5)
>>> J4 is a jumper board for +12 adjustments
>>> J3 is unused (battery backup boards)
>>> J2 is the inverter board (A3A2)
>>> J1 is the pre-regulator board (A3A1)
>>> Seems right but I know how bad things can go :-)
>>> Thanks!
>>> C

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