TEK 465 Scope - Power Supply Voltages

Main Page | Report this Page

Science Forum Index » Electronics - Repair Forum » TEK 465 Scope - Power Supply Voltages

Page 1 of 1

Author

Message

Guest

Posted: Fri Feb 16, 2007 11:44 pm

I left my 465 on for a few days and now there is no trace. All voltages are
correct except 2KV, 95V and 32V Unreg. The 32V blows the .25 amp fuse. Any
suggestions?
Thank you,
Dale

DaveM

Posted: Sat Feb 17, 2007 12:26 pm

Guest

<radiodale@att.net> wrote in message
news:cSuBh.69064$2m6.6040@bgtnsc05-news.ops.worldnet.att.net...

Quote:

I left my 465 on for a few days and now there is no trace. All voltages are
correct except 2KV, 95V and 32V Unreg. The 32V blows the .25 amp fuse. Any
suggestions?
Thank you,
Dale

I'm looking at the 465 and the 465B manual, and I don't see any of these low
voltage supplies. The only unregulated outputs are +120V and the unregulated
source for the +55V regulated output (actually +78V) and +15V unregulated. .
There is a +110 regulated output, but no 95V output.
Which version of the 465 do you have? (465/465A/465B)
--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

Some days you're the dog, some days the hydrant.

Jim Yanik

Posted: Sat Feb 17, 2007 3:51 pm

Guest

"DaveM" <masondg4499@comcast99.net> wrote in
news:OfidncWUwYlOsUrYnZ2dnUVZ_rOqnZ2d@comcast.com:

Quote:

radiodale@att.net> wrote in message
news:cSuBh.69064$2m6.6040@bgtnsc05-news.ops.worldnet.att.net...
I left my 465 on for a few days and now there is no trace. All
voltages are correct except 2KV, 95V and 32V Unreg. The 32V blows the
.25 amp fuse. Any suggestions?
Thank you,
Dale

I'm looking at the 465 and the 465B manual, and I don't see any of
these low voltage supplies. The only unregulated outputs are +120V
and the unregulated source for the +55V regulated output (actually
+78V) and +15V unregulated. . There is a +110 regulated output, but
no 95V output. Which version of the 465 do you have? (465/465A/465B)

It's a 465M,not truly a *465*. It's more like a 455A2B2 with wider BW.

The 32V-unreg runs the HV,he probably has a bad multiplier or CRT.

--
Jim Yanik
jyanik
at
kua.net

Jamie

Posted: Sun Feb 18, 2007 12:33 pm

Guest

radiodale@att.net wrote:

Quote:

Jim,
What do you suggest for the next trouble shooting step? Unplug the CRT? or?
Thanks,

If you have a HV-Probe, stick it on the Anode lead.
I don't know what the HV is suppose to be on that unit
how ever, the last one i looked at was aprox 12k.
I had to replace a trippler in old MIll Spec scope
made by Dumont years ago. i still have the scope at
it works nicely.. 60 Mhz..
I ended up making a new trippler using the old
case that was in there. because i too, left the
scope on for a couple of days and came back to
find the fuse blown out.
I used a dermal tool to remove all the old contents.
used some common HV diodes and got some caps together.
soldered them together on a predilled board with no
foil. laid it in the case, and used HV putty layers
at a time with a heat gun to fill the majority of it.
then top it off using silicone.
It works perfect..

What i did to test it, i disconnected the HV coil
lead going to the trippler. did a HV ac test from there.

Quote:

Dale
"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns98DA971CEB2C2jyanikkuanet@64.209.0.84...

"DaveM" <masondg4499@comcast99.net> wrote in
news:OfidncWUwYlOsUrYnZ2dnUVZ_rOqnZ2d@comcast.com:

radiodale@att.net> wrote in message
news:cSuBh.69064$2m6.6040@bgtnsc05-news.ops.worldnet.att.net...

I left my 465 on for a few days and now there is no trace. All
voltages are correct except 2KV, 95V and 32V Unreg. The 32V blows the
.25 amp fuse. Any suggestions?
Thank you,
Dale

I'm looking at the 465 and the 465B manual, and I don't see any of
these low voltage supplies. The only unregulated outputs are +120V
and the unregulated source for the +55V regulated output (actually
+78V) and +15V unregulated. . There is a +110 regulated output, but
no 95V output. Which version of the 465 do you have? (465/465A/465B)

It's a 465M,not truly a *465*. It's more like a 455A2B2 with wider BW.

The 32V-unreg runs the HV,he probably has a bad multiplier or CRT.

--
Jim Yanik
jyanik
at
kua.net

--
"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

Jim Yanik

Posted: Sun Feb 18, 2007 4:13 pm

Guest

<radiodale@att.net> wrote in
news:cJ_Bh.85192$2m6.82076@bgtnsc05-news.ops.worldnet.att.net:

Quote:

Jim,
What do you suggest for the next trouble shooting step? Unplug the
CRT? or?
Thanks,
Dale
"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns98DA971CEB2C2jyanikkuanet@64.209.0.84...
"DaveM" <masondg4499@comcast99.net> wrote in
news:OfidncWUwYlOsUrYnZ2dnUVZ_rOqnZ2d@comcast.com:

radiodale@att.net> wrote in message
news:cSuBh.69064$2m6.6040@bgtnsc05-news.ops.worldnet.att.net...
I left my 465 on for a few days and now there is no trace. All
voltages are correct except 2KV, 95V and 32V Unreg. The 32V blows
the .25 amp fuse. Any suggestions?
Thank you,
Dale

I'm looking at the 465 and the 465B manual, and I don't see any of
these low voltage supplies. The only unregulated outputs are +120V
and the unregulated source for the +55V regulated output (actually
+78V) and +15V unregulated. . There is a +110 regulated output,
but no 95V output. Which version of the 465 do you have?
(465/465A/465B)

It's a 465M,not truly a *465*. It's more like a 455A2B2 with wider
BW.

The 32V-unreg runs the HV,he probably has a bad multiplier or CRT.

--
Jim Yanik
jyanik
at
kua.net

disconnect the HV drive to the multiplier.The 95V should come up and the
32Vunreg fuse should not blow.

Do you have a 465M service manual?

--
Jim Yanik
jyanik
at
kua.net

Guest

Posted: Sun Feb 18, 2007 5:59 pm

Thanks Jim. Yes, I have the manual on CD.
Dale

"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns98DB9AF3346BDjyanikkuanet@64.209.0.85...

Quote:

radiodale@att.net> wrote in
news:cJ_Bh.85192$2m6.82076@bgtnsc05-news.ops.worldnet.att.net:

Jim,
What do you suggest for the next trouble shooting step? Unplug the
CRT? or?
Thanks,
Dale
"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns98DA971CEB2C2jyanikkuanet@64.209.0.84...
"DaveM" <masondg4499@comcast99.net> wrote in
news:OfidncWUwYlOsUrYnZ2dnUVZ_rOqnZ2d@comcast.com:

radiodale@att.net> wrote in message
news:cSuBh.69064$2m6.6040@bgtnsc05-news.ops.worldnet.att.net...
I left my 465 on for a few days and now there is no trace. All
voltages are correct except 2KV, 95V and 32V Unreg. The 32V blows
the .25 amp fuse. Any suggestions?
Thank you,
Dale

I'm looking at the 465 and the 465B manual, and I don't see any of
these low voltage supplies. The only unregulated outputs are +120V
and the unregulated source for the +55V regulated output (actually
+78V) and +15V unregulated. . There is a +110 regulated output,
but no 95V output. Which version of the 465 do you have?
(465/465A/465B)

It's a 465M,not truly a *465*. It's more like a 455A2B2 with wider
BW.

The 32V-unreg runs the HV,he probably has a bad multiplier or CRT.

--
Jim Yanik
jyanik
at
kua.net

disconnect the HV drive to the multiplier.The 95V should come up and the
32Vunreg fuse should not blow.

Do you have a 465M service manual?

--
Jim Yanik
jyanik
at
kua.net

Guest

Posted: Sun Feb 18, 2007 9:17 pm

Jim,
I disconnected the HV drive at pin 10 of the transformer where it is
connected to the HV multiplier. Fuse still blows. What next?
Dale

"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns98DB9AF3346BDjyanikkuanet@64.209.0.85...

Quote:

Sam Goldwasser

Posted: Mon Feb 19, 2007 8:55 am

Guest

<radiodale@att.net> writes:

Quote:

Jim,
I disconnected the HV drive at pin 10 of the transformer where it is
connected to the HV multiplier. Fuse still blows. What next?

This isn't the usual shorted tantalum cap problem? :)

--- sam | Sci.Electronics.Repair FAQ: 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 Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

Jim Yanik

Posted: Mon Feb 19, 2007 1:14 pm

Guest

Sam Goldwasser <sam@minus.seas.upenn.edu> wrote in
news:6wfy92b92a.fsf@minus.seas.upenn.edu:

Quote:

radiodale@att.net> writes:

Jim,
I disconnected the HV drive at pin 10 of the transformer where it is
connected to the HV multiplier. Fuse still blows. What next?

Was that the wire from a post on the side of the multiplier to a separate
post on the xfmr?

Quote:

This isn't the usual shorted tantalum cap problem? Smile

then the HV osc xstr is probably failed.

time to troubleshoot.

BTW,there's an excellent circuit description in the service manual that
tells how the circuits work,I always referred back to them,I consider them
invaluable.I hope they included it on your CDROM.

--
Jim Yanik
jyanik
at
kua.net

dale

Posted: Mon Feb 19, 2007 10:00 pm

Guest

Jim,
Yes, the lead I disconnected was from a post on the multiplier to a separate
post on the xfmr. Sam mentions a tantalum cap. Is there a certain one that I
should check? If the osc transistor failed would it load down the supplies?
I'll be on travel for a few days and unable to do any more testing until
Thursday pm. Can I write you at kua.net?
Thanks,
Dale
"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns98DC7C82ABDF6jyanikkuanet@64.209.0.85...

Quote:

Sam Goldwasser <sam@minus.seas.upenn.edu> wrote in
news:6wfy92b92a.fsf@minus.seas.upenn.edu:

radiodale@att.net> writes:

Jim,
I disconnected the HV drive at pin 10 of the transformer where it is
connected to the HV multiplier. Fuse still blows. What next?

Was that the wire from a post on the side of the multiplier to a separate
post on the xfmr?

This isn't the usual shorted tantalum cap problem? :)

then the HV osc xstr is probably failed.

time to troubleshoot.

BTW,there's an excellent circuit description in the service manual that
tells how the circuits work,I always referred back to them,I consider them
invaluable.I hope they included it on your CDROM.

--
Jim Yanik
jyanik
at
kua.net

Jim Yanik

Posted: Tue Feb 20, 2007 1:50 am

Guest

"dale" <radiodale@att.net> wrote in news:ZCsCh.1340$XT.705@trnddc06:

Quote:

Don't you think a shorted xstr would blow the 32Vunreg fuse?

Quote:

I'll be on travel for a few days and unable to
do any more testing until Thursday pm. Can I write you at kua.net?

FIRST,I suggest you READ THE CIRCUIT DESCRIPTION for the HV oscillator.
Then you should know how to troubleshoot it. I'm not going to tell you
"check this,then this ,then this".....ad infinitum.

I also do not have any TEK manuals to reference,I work from memory.

--
Jim Yanik
jyanik
at
kua.net

Quote:

Thanks,
Dale
"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns98DC7C82ABDF6jyanikkuanet@64.209.0.85...
Sam Goldwasser <sam@minus.seas.upenn.edu> wrote in
news:6wfy92b92a.fsf@minus.seas.upenn.edu:

radiodale@att.net> writes:

Jim,
I disconnected the HV drive at pin 10 of the transformer where it
is connected to the HV multiplier. Fuse still blows. What next?

Was that the wire from a post on the side of the multiplier to a
separate post on the xfmr?

This isn't the usual shorted tantalum cap problem? :)

then the HV osc xstr is probably failed.

time to troubleshoot.

BTW,there's an excellent circuit description in the service manual
that tells how the circuits work,I always referred back to them,I
consider them invaluable.I hope they included it on your CDROM.

--
Jim Yanik
jyanik
at
kua.net

Page 1 of 1 All times are GMT - 5 Hours The time now is Sun Oct 12, 2008 4:27 pm Science Forum Index