Tektronix 2465 dim traces and no vertical movement
 

Hi,

I got a used Tektronix 2465 oscilloscope with some problems and I was hoping
if anyone has suggestions in how to fix it. I would rather fix it rather
than sell it for parts.

It powers up fine but the display is very dim, and it becomes dimmer as the
time passes. I have to turn the lights off to see it. Adjusting the
intensity has no effect, it doesn't become brighter or dimmer, however,
pressing the beam finder brightens the display a bit. Readout intensity has
no effect, but I see 2 bright spots in the beam, I assume they are readouts.
Their intensity is fixed regardless of any adjustment.

The scope also has no vertical movement. I could see the trace as a
horizontal line in the center, and it responds to the horizontal position
knob, as a normal scope would, but it doesn't go up and down when I adjust
the vertical position. I already read in the newsgroup archives about the
problems with the horizontal output IC, U800, but this scope seems to have a
working one. It's part number TEK 155-0241-02.

Finally, I have only the operations manual, but not the service manual. Does
anybody have the service manual in PDF format? My email can handle up to
6.67 MB attachments. You can email it to n18 AT cox.net

I already have the 2465B service manual, but it's not the same. Downloaded
from here(See Tek):

http://bama.edebris.com/manuals/

Thank you

I checked further and I have noticed missing chips on the board. Are these
optional?

U400 155-0236-XX CH SWITCH
U600 155-0237-XX VERT OUT
U950 155-0242-XX Z AXIS

These look like PLCC sockets.



"Someone" wrote in message
news:_5vGe.21334$Eo.19333@fed1read04...
Hi,

I got a used Tektronix 2465 oscilloscope with some problems and I was
hoping if anyone has suggestions in how to fix it. I would rather fix it
rather than sell it for parts.

It powers up fine but the display is very dim, and it becomes dimmer as
the time passes. I have to turn the lights off to see it. Adjusting the
intensity has no effect, it doesn't become brighter or dimmer, however,
pressing the beam finder brightens the display a bit. Readout intensity
has no effect, but I see 2 bright spots in the beam, I assume they are
readouts. Their intensity is fixed regardless of any adjustment.

The scope also has no vertical movement. I could see the trace as a
horizontal line in the center, and it responds to the horizontal position
knob, as a normal scope would, but it doesn't go up and down when I adjust
the vertical position. I already read in the newsgroup archives about the
problems with the horizontal output IC, U800, but this scope seems to have
a working one. It's part number TEK 155-0241-02.

Finally, I have only the operations manual, but not the service manual.
Does anybody have the service manual in PDF format? My email can handle up
to 6.67 MB attachments. You can email it to n18 AT cox.net

I already have the 2465B service manual, but it's not the same. Downloaded
from here(See Tek):

http://bama.edebris.com/manuals/

Thank you

"Someone" wrote in news:f8wGe.21341$Eo.1465@fed1read04:

I checked further and I have noticed missing chips on the board. Are
these optional?

U400 155-0236-XX CH SWITCH
U600 155-0237-XX VERT OUT
U950 155-0242-XX Z AXIS

These look like PLCC sockets.



Bad news;you have bought a cannabalized scope,and those TEK-made ICs(hybrid
IC's) are no longer available from TEK(the sole source for them).
There are NO substitutes for them.
And the sockets are TEK-specific,not standard PLCC.

Your only recourse is to buy another "parts scope" and use the ICs from
that one to replace the missing IC's.
There's a small chance that some folks are selling parts from 2400 series
they are cannabalizing themselves.
Ebay might turn up some.

--
Jim Yanik
jyanik
at
kua.net



"Someone" wrote in message
news:_5vGe.21334$Eo.19333@fed1read04...
Hi,

I got a used Tektronix 2465 oscilloscope with some problems and I was
hoping if anyone has suggestions in how to fix it. I would rather fix
it rather than sell it for parts.

It powers up fine but the display is very dim, and it becomes dimmer
as the time passes. I have to turn the lights off to see it.
Adjusting the intensity has no effect, it doesn't become brighter or
dimmer, however, pressing the beam finder brightens the display a
bit. Readout intensity has no effect, but I see 2 bright spots in the
beam, I assume they are readouts. Their intensity is fixed regardless
of any adjustment.

The scope also has no vertical movement. I could see the trace as a
horizontal line in the center, and it responds to the horizontal
position knob, as a normal scope would, but it doesn't go up and down
when I adjust the vertical position. I already read in the newsgroup
archives about the problems with the horizontal output IC, U800, but
this scope seems to have a working one. It's part number TEK
155-0241-02.

Finally, I have only the operations manual, but not the service
manual. Does anybody have the service manual in PDF format? My email
can handle up to 6.67 MB attachments. You can email it to n18 AT
cox.net

I already have the 2465B service manual, but it's not the same.
Downloaded from here(See Tek):

http://bama.edebris.com/manuals/

Thank you









--
Jim Yanik
jyanik
at
kua.net

I have several 2465's in either repairable or operational condition That I'm
willing to sell if interested let me know
Bob
"Someone" wrote in message
news:f8wGe.21341$Eo.1465@fed1read04...
I checked further and I have noticed missing chips on the board. Are these
optional?

U400 155-0236-XX CH SWITCH
U600 155-0237-XX VERT OUT
U950 155-0242-XX Z AXIS

These look like PLCC sockets.



"Someone" wrote in message
news:_5vGe.21334$Eo.19333@fed1read04...
Hi,

I got a used Tektronix 2465 oscilloscope with some problems and I was
hoping if anyone has suggestions in how to fix it. I would rather fix it
rather than sell it for parts.

It powers up fine but the display is very dim, and it becomes dimmer as
the time passes. I have to turn the lights off to see it. Adjusting the
intensity has no effect, it doesn't become brighter or dimmer, however,
pressing the beam finder brightens the display a bit. Readout intensity
has no effect, but I see 2 bright spots in the beam, I assume they are
readouts. Their intensity is fixed regardless of any adjustment.

The scope also has no vertical movement. I could see the trace as a
horizontal line in the center, and it responds to the horizontal position
knob, as a normal scope would, but it doesn't go up and down when I
adjust the vertical position. I already read in the newsgroup archives
about the problems with the horizontal output IC, U800, but this scope
seems to have a working one. It's part number TEK 155-0241-02.

Finally, I have only the operations manual, but not the service manual.
Does anybody have the service manual in PDF format? My email can handle
up to 6.67 MB attachments. You can email it to n18 AT cox.net

I already have the 2465B service manual, but it's not the same.
Downloaded from here(See Tek):

http://bama.edebris.com/manuals/

Thank you