HP 3325A function generator frontpanel went black - Any idea

[Anders Johansson]

My HP 3325A suddenly went black, and will not respond to pressed keys.

The cpu seems to be running but the only clock on the front panel interface
I can see
is the LWKD that clocks 7-segment data. The other two clocks are permanently
high.
They come from two different LS138's so I find it hard to believe both chips
failed.

Is there any way the the cpu can programatically decide to not clock the
front panel?

The power supplies are OK.

Can anyone help me with some idea of how to proceed?

Thanks,
Anders J

 

[Michael A. Terrell]

Anders Johansson wrote:

My HP 3325A suddenly went black, and will not respond to pressed keys.

The cpu seems to be running but the only clock on the front panel interface
I can see
is the LWKD that clocks 7-segment data. The other two clocks are permanently
high.
They come from two different LS138's so I find it hard to believe both chips
failed.

Is there any way the the cpu can programatically decide to not clock the
front panel?

The power supplies are OK.

Can anyone help me with some idea of how to proceed?

Thanks,
Anders J

Yes, make sure you have the full manual, and that its for the right
serial number range. If that's too much trouble, ship it to me for
parts. ;-)


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Anders Johansson]

Anders Johansson wrote:

My HP 3325A suddenly went black, and will not respond to pressed keys.

The cpu seems to be running but the only clock on the front panel
interface
I can see
is the LWKD that clocks 7-segment data. The other two clocks are
permanently
high.
They come from two different LS138's so I find it hard to believe both
chips
failed.

Is there any way the the cpu can programatically decide to not clock the
front panel?

The power supplies are OK.

Can anyone help me with some idea of how to proceed?

Thanks,
Anders J


Yes, make sure you have the full manual, and that its for the right
serial number range. If that's too much trouble, ship it to me for
parts. ;-)

Michael A. Terrell
Central Florida

I have the manual, so that's not an issue.
Perhaps reading and understanding it is an issue :-(

The problem is that it seems that the cpu is not clocking data to
to the front panel, which I find a bit hard to believe. That why I'm looking
for ideas concerning this.

* Is there e legitimate way for the generator to totally blank its front
panel?
* If not what could cause this, except for a cpu failure. On the other hand,
other clocks and signals are there so it's not entirely dead.

Thanks for any input,
Anders J

 

[Michael A. Terrell]

Anders Johansson wrote:

I have the manual, so that's not an issue.
Perhaps reading and understanding it is an issue :-(

The problem is that it seems that the cpu is not clocking data to
to the front panel, which I find a bit hard to believe. That why I'm looking
for ideas concerning this.

* Is there e legitimate way for the generator to totally blank its front
panel?
* If not what could cause this, except for a cpu failure. On the other hand,
other clocks and signals are there so it's not entirely dead.

Thanks for any input,
Anders J

I serviced one of the B versions about seven years ago. It is a
complex instrument that our in house cal lab couldn't handle, so I
helped find some bad chips in the control logic. I don't remember
enough after seven years to help you, without the schematic in front of
me. Make sure all the supply voltages are there, and in spec, to start
with. After that, I would check the electrolytic capacitors. If its more
than that, you might have to send it to a good cal lab.


I just found and downloaded a 3325B manual on the Agilent website, but
I haven't had time to look at it yet.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida