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 .
replacing VERT switching and VERT out amp didn't help , maybe some of you guys know what should i go for next ?
snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@22g2000hsm.googlegroups.com:
checked with a scope?
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 ;)
" snipped-for-privacy@gmail.com" wrote in news: snipped-for-privacy@57g2000hsv.googlegroups.com:
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
innews: snipped-for-privacy@57g2000hsv.googlegroups.com:
no , on the little board that located on the right , the keypad connected to that board .
i got every tek model service manual ;)
" snipped-for-privacy@gmail.com" wrote in news: snipped-for-privacy@r34g2000hsd.googlegroups.com:
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 ?
" snipped-for-privacy@gmail.com" wrote in news: snipped-for-privacy@19g2000hsx.googlegroups.com:
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.
-- Jim Yanik jyanik at kua.net
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
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
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
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.
Speaking of which, are the manuals-on-CD any good (e.g. Micromanuals for $8.98 at
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
snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@w3g2000hsg.googlegroups.com:
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.
Possibly aging electrolytics in the PS;Bad ESR.
-- Jim Yanik jyanik at kua.net
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. ;)
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