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Tektronix 2445B Scope Problem , Help needed (Video Included)

J

Jim Yanik

Jan 1, 1970
0
[email protected] wrote in
http://video.google.com/videoplay?docid=8513588739057530758&hl=en

as you can see , all 4 channels traces jumps like crazy .
Readout is fine , only the trace is jumpy , in any time base and also
in X-Y mode ....


All power supply voltage range is fine .

checked with a scope?
replacing VERT switching and VERT out amp didn't help , maybe some of
you guys know what should i go for next ?

there's a lot of 0.1uf caps that can cause problems.
Check the decoupled power supply lines for the vertical,and perhaps the
position voltages coming from the microprocessor board.
I know that's a lot of work.

Maybe some chiller spray on each cap.....although it's better to scope the
lines.
 
there's a lot of 0.1uf caps that can cause problems.
Check the decoupled power supply lines for the vertical,and perhaps the
position voltages coming from the microprocessor board.
I know that's a lot of work.

Maybe some chiller spray on each cap.....although it's better to scope the
lines.

--
Jim Yanik
jyanik
at
kua.net


Well , the problem was in the position microprocessor board .
the caps are dead ...

thanks ;)
 
J

Jim Yanik

Jan 1, 1970
0
Well , the problem was in the position microprocessor board .
the caps are dead ...

thanks ;)

the ones on the sample&hold amps?

FYI,the circuit description for the 2445/65 series is EXCELLENT and a must-
read.
It's how I taught myself the 2465 before I went to TEK training on it,and I
knew it as well as the instructor.
I made copious notes on the schematics throughout my reading,used colored
markers to trrace out signal and data paths. I regret not bringing my
manuals out with me,but I had no room to store them.

I also coulda made a lot of money selling manuals on Ebay.... ;-(
 
the ones on the sample&hold amps?

FYI,the circuit description for the 2445/65 series is EXCELLENT and a must-
read.
It's how I taught myself the 2465 before I went to TEK training on it,and I
knew it as well as the instructor.
I made copious notes on the schematics throughout my reading,used colored
markers to trrace out signal and data paths. I regret not bringing my
manuals out with me,but I had no room to store them.

I also coulda made a lot of money selling manuals on Ebay.... ;-(

--
Jim Yanik
jyanik
at
kua.net

no , on the little board that located on the right , the keypad
connected to that board .

i got every tek model service manual ;)
 
J

Jim Yanik

Jan 1, 1970
0
no , on the little board that located on the right , the keypad
connected to that board .

i got every tek model service manual ;)

the right side PCB is the (IIRC,A5) microprocessor assembly(controls
everything),where the S&H amps and caps are located.That is how the
position and reference voltages are created;a MUXed DA converter and S&H
caps and buffer amps.There are even exerciser routines to check the range
of output voltages from them,as you vary the front panel controls.
 
the right side PCB is the (IIRC,A5) microprocessor assembly(controls
everything),where the S&H amps and caps are located.That is how the
position and reference voltages are created;a MUXed DA converter and S&H
caps and buffer amps.There are even exerciser routines to check the range
of output voltages from them,as you vary the front panel controls.

--
Jim Yanik
jyanik
at
kua.net

thanks for the info ;)


i got another problem with 2430A , its got this DALLAS memory+battery
chip (U350 if i recall) , and of course the battery is dead .
the CAL data can't be saved , and you can't find those chips anymore .

is there any other solution ?
 
J

Jim Yanik

Jan 1, 1970
0
thanks for the info ;)


i got another problem with 2430A , its got this DALLAS memory+battery
chip (U350 if i recall) , and of course the battery is dead .
the CAL data can't be saved , and you can't find those chips anymore .

is there any other solution ?

I don't have any experience with the 2430 series scopes,so I can't help you
there.Seems that you could possibly find a similar non-integral battery
type IC,and sub that in with it's own backup battery that you can replace.
you can probably find someone with the exact IC stockpiled,maybe that
Canadian company,Sphere.

Regardless,you would have to recal the scope to load new CAL constants into
the memory.
 
M

msg

Jan 1, 1970
0
Chris said:
[email protected] wrote:



They used those DALLAS battery + memory + real time clock things in old Sun
workstations, but possibly a different part number. From what I remember,
there are enthusiasts who worked out exactly where you have to drill to
attach wires to the battery and apply external power, try google.
<snip>

Indeed, I resisted answering the original post but since you mentioned this,
I can confirm that it is a good option. I have added external batteries to
the NVRAM/RTC chips on my Sun IPX workstations. The procedure is
well documented and it works well. No need to trash the part, just
restore its power supply.

Regards,

Michael
 
C

Chris Jones

Jan 1, 1970
0
thanks for the info ;)


i got another problem with 2430A , its got this DALLAS memory+battery
chip (U350 if i recall) , and of course the battery is dead .
the CAL data can't be saved , and you can't find those chips anymore .

is there any other solution ?

They used those DALLAS battery + memory + real time clock things in old Sun
workstations, but possibly a different part number. From what I remember,
there are enthusiasts who worked out exactly where you have to drill to
attach wires to the battery and apply external power, try google. Failing
that, if you know someone who assembles BGA circuit boards, they should
have a suitable x-ray inspection system that you could use to see where the
battery is, and where you have to cut into it.

Chris
 
C

Chris Jones

Jan 1, 1970
0
thanks for the info ;)


i got another problem with 2430A , its got this DALLAS memory+battery
chip (U350 if i recall) , and of course the battery is dead .
the CAL data can't be saved , and you can't find those chips anymore .

is there any other solution ?

BTW I have an unwanted DS12887 if that is what you need, however mine
probably also has a flat battery. It might be of use if you need to
practice some surgery before attacking your own. Let me know (on usenet,
not e-mail) if you want it.

Chris
 
R

Remove _ for valid address

Jan 1, 1970
0
i got another problem with 2430A , its got this DALLAS memory+battery
chip (U350 if i recall) , and of course the battery is dead .
the CAL data can't be saved , and you can't find those chips anymore .

If it's a typical "chunky" device like the DS1287, then internally it's
a small PCB with two Dallas chips on it (one sram, one battery backup
controller). On top of the PCB is a regular PCB mount 3V lithium cell.
So it is possible to carve the device open (in from the top side) and
fit a new cell.

Mike.
 
FYI,the circuit description for the 2445/65 series is EXCELLENT and a
must-read. It's how I taught myself the 2465 before I went to TEK training
on it,and I knew it as well as the instructor. I made copious notes on the
schematics throughout my reading,used colored markers to trrace out
signal and data paths. I regret not bringing my manuals out with me, but
I had no room to store them.

I also coulda made a lot of money selling manuals on Ebay.... ;-(

Speaking of which, are the manuals-on-CD any good
(e.g. Micromanuals for $8.98 at
http://cgi.ebay.com/Tek-TEKTRONIX-2...Z40123QQrdZ1QQssPageNameZWD1VQQcmdZViewItem)?
I'm presuming they are scanned from an original and converted to PDF
(so
there won't be any links or text search available), is the image
quality decent?

I have a 2465B that takes a few minutes to turn on (except for the
bulb
check flash) and has some wiggle in the text readout, so I suspect
that
some of the supplies are going soft.

Thanks,
TM
 
J

Jim Yanik

Jan 1, 1970
0
[email protected] wrote in
Speaking of which, are the manuals-on-CD any good
(e.g. Micromanuals for $8.98 at
http://cgi.ebay.com/Tek-TEKTRONIX-2465B-2467B-CALI-Service-Main-MANUAL_
W0QQitemZ7603566629QQihZ017QQcategoryZ40123QQrdZ1QQssPageNameZWD1VQQcmd
ZViewItem)? I'm presuming they are scanned from an original and
converted to PDF (so
there won't be any links or text search available), is the image
quality decent?

I have no idea,never having seen any of them.
Image quality is going to depend on the scanner used.
I don't know if they include the circuit descriptions,either.
People seem to overlook them.
(or people are just too F'ing LAZY to read them,instead preferring to ask
questions here,hoping for a "quick fix". But some techs at TEK were the
same way.)

$9 is not a bad price for a CD if it is a fair and complete manual copy.
A SERVICE manual,not an operators manual!! (also not just a CAL procedure
and adj. locations diagram)
Worth ordering one just to see. If you do,post a review on it here,please.
I have a 2465B that takes a few minutes to turn on (except for the
bulb
check flash) and has some wiggle in the text readout, so I suspect
that
some of the supplies are going soft.

Possibly aging electrolytics in the PS;Bad ESR.
 
J

JW

Jan 1, 1970
0
Speaking of which, are the manuals-on-CD any good
(e.g. Micromanuals for $8.98 at
http://cgi.ebay.com/Tek-TEKTRONIX-2...Z40123QQrdZ1QQssPageNameZWD1VQQcmdZViewItem)?

That's for the 2465B/67B.
I'm presuming they are scanned from an original and converted to PDF
(so
there won't be any links or text search available), is the image
quality decent?

If I don't already have them, I always look for Artekmedia manuals first.
Most of their manuals *are* text searchable, and their scans are high
quality. My only complaint is that they are password protected limiting
some functionality, but that's easily removed. ;)
http://www.artekmedia.com/ They don't have the 2445B, but I'll check my
collection today when I get to my other job. If I have it, I'll post back
to this thread tomorrow.
 
J

Jim Yanik

Jan 1, 1970
0
That's for the 2465B/67B.


If I don't already have them, I always look for Artekmedia manuals
first. Most of their manuals *are* text searchable, and their scans
are high quality. My only complaint is that they are password
protected limiting some functionality, but that's easily removed. ;)
http://www.artekmedia.com/ They don't have the 2445B, but I'll check
my collection today when I get to my other job. If I have it, I'll
post back to this thread tomorrow.

The only difference between the 2445 and 2465(including A and B versions)
is the bandwidth,which is determined by the main PCB itself.
 

W5UQ

Apr 5, 2008
2
Joined
Apr 5, 2008
Messages
2
TEK 2445 LED's flash at turn on and won't work.

My TEK 2445 has been sitting for 6 months while I moved and built a new shop. Now the sweep LED's flash at turn on and that's all. Nothing else happens. LED's all not on. No trace. W5UQ at att dot net to contact me direct.
I've heard it is the processor chip and that they are not available anymore. Is that right? Any one know?
Bob
[email protected]
 
Last edited:

onins

Feb 25, 2010
1
Joined
Feb 25, 2010
Messages
1
Hello, you can try to visit our website..we are capable on test equipments repair and calibration. please check this out microprecision.com website
 
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