HP DeslJet 500 AC Adapter

J

John Keiser

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Does anyone know the pinout voltages?

Should be 20 VAC out but I have 2 units and they show different volatges
between the 4 pins.

[My DJ50 and DJ 520 both display all LEDs green and neither initializes.
Swapping the AC adapters doesn't help.].

Thanks.


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"John Keiser" <john.keiser2@verizon.net> wrote in message
news:c0cmad$14vfok$1@ID-128410.news.uni-berlin.de...
Does anyone know the pinout voltages?

Should be 20 VAC out but I have 2 units and they show different volatges
between the 4 pins.

[My DJ50 and DJ 520 both display all LEDs green and neither initializes.
Swapping the AC adapters doesn't help.].

Thanks.
Click to expand...

If they're switching power supplies which I suspect they are, you have to
test the output under load.
 
"James Sweet" <jamessweet@hotmail.com> writes:

If they're switching power supplies which I suspect they are, you have to
test the output under load.
Click to expand...
The adapters themselves for some of these printers are just AC. There
is a switchmode power supply inside the printer.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
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Not a swithcing PS... just an AC transformer AFAIK but with 4 pins.

I kept 2 of these old DeskJets so I could "easily" cannabalize one and keep
the other working. Although different models, they share the same board
number for the internal switching PS.

Both have failed with all the green LEDs "on" and don't initialize.

The failure of both lightly used units at the same time is baffling. But
since the AC adapters show differnet voltages, I was hoping to start there
and verify correct output.

Any clues appreciated.

Thanks.

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"John Keiser" <john.keiser2@verizon.net> writes:

Not a swithcing PS... just an AC transformer AFAIK but with 4 pins.

I kept 2 of these old DeskJets so I could "easily" cannabalize one and keep
the other working. Although different models, they share the same board
number for the internal switching PS.

Both have failed with all the green LEDs "on" and don't initialize.

The failure of both lightly used units at the same time is baffling. But
since the AC adapters show differnet voltages, I was hoping to start there
and verify correct output.
Click to expand...
How different are they? I wouldn't worry about the difference
between 19 and 21 VAC or something like that. Just different
production runs.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the feedback form on the S.E.R FAQ Web sites.
 
Pins 1-2 = 11v; 1-3 = 22v on both adapters.

Pins 1-4 = 3.5 on one and 13.5 on the other.

I suspect that pin 1-4 is not a proper connection but as it is a major
varience, I was hoping for guidnace before I dig into the "sealed" units to
look further.

Thank you.


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"John Keiser" <john.keiser2@verizon.net> writes:

Pins 1-2 = 11v; 1-3 = 22v on both adapters.

Pins 1-4 = 3.5 on one and 13.5 on the other.

I suspect that pin 1-4 is not a proper connection but as it is a major
varience, I was hoping for guidnace before I dig into the "sealed" units to
look further.
Click to expand...
May just be capacitive coupling into open wires. Put a 1K resistor or
some modest load across the meter leads and see if there is still
significant voltage.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the feedback form on the S.E.R FAQ Web sites.
 
I would think it is the power supply board or some other fault in the
printers. The reduced AC voltage from your adaptor units goes to a bridge
rectifier, some filter caps, and then to a switch mode power supply module
in most of these printers. This may also be called an inverter module in
this type of case. Some of these printers have a more simple approach such
as only a bridge rectifier, filter caps, and a number of voltage regulators
feeding the various parts of the printer as needed. Naturally in any case,
there will be a fair number of components involved in the complete process
no matter what type of supply you have. You would have to open the printer
to really know.

If these printers are out of warranty and the fault is not a simple fix, it
will pay more to replace them than to service them.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"John Keiser" <john.keiser2@verizon.net> wrote in message
news:c0cmad$14vfok$1@ID-128410.news.uni-berlin.de...
Does anyone know the pinout voltages?

Should be 20 VAC out but I have 2 units and they show different volatges
between the 4 pins.

[My DJ50 and DJ 520 both display all LEDs green and neither initializes.
Swapping the AC adapters doesn't help.].

Thanks.


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Remove -NOSPAM- to contact me.
 
On Tue, 10 Feb 2004 21:40:57 -1000, "John Keiser"
<john.keiser2@verizon.net> wrote:

Does anyone know the pinout voltages?

Should be 20 VAC out but I have 2 units and they show different volatges
between the 4 pins.

[My DJ50 and DJ 520 both display all LEDs green and neither initializes.
Swapping the AC adapters doesn't help.].

Thanks.
Click to expand...
Have repaired a couple of them some years ago so thats why I don't
know the right values anymore (excuses)

On the main board are two electrolytic capcitors. Exchange them both.
Also clean the cartridge connectors with a piece of cloth with
alcohol.

Seems a problem of all the HP 500 series.

Rinus
 
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