Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- TekScopes
- Messages
Search
|
Re: 2220 POST displays a large X on the screen
I don't recall exactly how the 2220 was differentiated from the 2230 for product positioning, but I do know the guts are mostly the same. I think the 2220 was reduced in performance by limiting the BW to 60 MHz (with parts on the main board) vs 100 for the 2230, and maybe lower sample rate and record length. I think the brain identified the model by jumpers (0 ohm resistor jumpers) on the digital board, although they may instead have different ROMs. If anyone with these models can compare, it would be evident. I also thought the 2220 had on-screen readout, but fewer features within the operating menus.
If the ROMs are the same between models, this could be a case where a 2220 can be mostly converted to a 2230, except for any major items missing. I saw the picture of the big X - it certainly is big, and appears to be generated by the digital display system, like a calibration signal to align the storage mode to the CRT face. Maybe there's a jumper or DIP switch set to the wrong position, or loose, forcing a cal mode. Another possibility is that it's a fault indicator showing X-out - that there's a major problem such as the brain being confused about what model it should be, so it just sits there. Perhaps there's an intermittent fault in the ID process, or maybe someone hacked it part way and got it all confused. Obviously, the brain must be working in order to present the X on screen. I'd recommend studying the manuals and circuits and boards and ROMs and jumpers and DIP switches to see if anything looks different from normal. Especially check in the adjustments section, to see what's done for aligning the store/nonstore registration. I'd guess it's a jumper or DIP switch setting, rather than a diagnostic menu item, to make the X, and pots on the vector board to tweak it to the CRT. Ed |
|
New to Group, looking for help with Tek 465 Repair
Hi all, just introducing myself and my current project to the group. I am a web programmer during the day but have always been interested in electronics. Always have been a 'part swapper' level of a electronic repair tech but know a bit of theory and how to read schematics etc. Also am a fan of audio tube amplifiers and looking to build my own circuits for home audio projects (preamp, active crossovers). Also need to fix a TV power supply for my brother at the moment; and have a tape deck I need to diagnose deeper than I can do with a DMM. So now I'm wanting to learn more; taking a class and just now getting into scopes and the deeper math side of things. But sticking with low Mhz needs and analog for starters.
Picked up a Tek 465 off Craiglist on Monday - it has a single non-sweeping dot in the center and a toasty hot sweep IC. I've been following the service manual diag steps and seeing low voltage on the +5v rail until the horizontal amp board connector is removed, then it stabilizes to 5v per my DMM. No -8v to be seen but solid +55 and +15. I have been told on the EEBlog forum to check for ripple; seems I need to buy another (working) scope to get that confirmed which I think I'll do. Any chance the less expensive USB O-Scopes can do ripple? I see the custom Tek Sweep IC can be had from some specialty web sites so I may order one of those based on mine running too hot to touch. Otherwise I'm planning to test and swap all caps and transistors as needed. I also have a quality Tek o-probe on the way and a good Weller soldering station and pretty well equipped bench. Thanks in advance; I'm hoping to ask more detailed questions as I have them but am starting testing from the power supply end. - Neil |
|
Re: New file uploaded to TekScopes
Besides, the links don't work. In the "New file..." messages the folder name is either truncated (too long?), or changed afterwards in the Files section (is that possible?). Very strange, the text -fixed is removed from the folder name and replaced by a space.
toggle quoted message
Show quoted text
Albert ---In TekScopes@..., <malcolm.r.hunter@...> wrote : Hi Darren, If you upload photos to the Photos section, people can view them in their web browser rather than having to download them first. Malcolm On 30 March 2016 at 14:42, <TekScopes@... mailto:TekScopes@...> wrote:
> > > > Hello, > > This email message is a notification to let you know that > a file has been uploaded to the Files area of the TekScopes > group. > > File : /2247A-PSU-BurnMark-Near-A18R2254 /Before-1of1.jpg > Uploaded by : darren_ting_hc <darren_ting_hc@... mailto:darren_ting_hc@...> > Description : Before Recap and burn mark fix > > You can access this file at the URL: > > > > To learn more about file sharing for your group, please visit: > > > > Regards, > > darren_ting_hc <darren_ting_hc@... mailto:darren_ting_hc@...> |
|
Re: Question Regarding Power Supply Ripple Measurement - 2465B
Barry, it's what you suggest, it will be ripple after double rectification. But the repetition frequency is still 60 Hz; only in case of ideal symmetry the frequency appears as 120 Hz.
Hence set the trigger mode at LINE. If you trigger on the signal then the trigger circuitry will normally recognize 120 positive (at + slope) level crossings per second. Depending on sweep speed and hold-off time you have two alternating waveforms superimposed, or "at random" one of these two (maybe stable, maybe now and then jumping to the other waveform). Albert ---In TekScopes@..., <n4buq@...> wrote : In the 2400 series manuals, the table that defines the measurements for voltage and ripple state (for ripple measurement): p-p Ripple at Two Times Line Frequency How is this supposed to be done? With a 60Hz line frequency (U.S.), is this supposed to be performed with the scope measuring the ripple triggered at 120Hz or am I misinterpreting what's being stated? Is it simply assumed that any ripple will present itself at twice the line frequency (full-wave rectification) and the scope being used to measure this will simply trigger at that frequency (assumedly using a fairly slow sweep speed to better see the waveform)? Thanks, Barry - N4BUQ |
|
Re: Question Regarding Power Supply Ripple Measurement - 2465B
They are referring to ripple produced by the 120 Hz variation from the
toggle quoted message
Show quoted text
full wave rectifier at the input. Set the measuring oscilloscope to line triggering; that is what it is there for. On Wed, 30 Mar 2016 11:31:48 -0400 (EDT), you wrote:
In the 2400 series manuals, the table that defines the measurements for voltage and ripple state (for ripple measurement): |
|
Re: 2220 POST displays a large X on the screen
Data on the 2220 and 2221 is pretty slim; I have never see schematics
toggle quoted message
Show quoted text
or the service manual for them. Similarities with the 2230 which make it the closest match and 2235 series in general include: - Production dates coinciding with the 2230. - 20pF input capacitance and 2mV/div sensitivity. - Maximum 50ns/div unmagnified sweep. - 20 MS/s digitizer and 100ns peak detect. Will the 2230 display an X for diagnostic purposes? I do not remember. On Wed, 30 Mar 2016 11:37:44 +0000 (UTC), you wrote:
HiSorry, I thought I had posted an image. I've added one to the albums: |
|
Question Regarding Power Supply Ripple Measurement - 2465B
In the 2400 series manuals, the table that defines the measurements for voltage and ripple state (for ripple measurement):
p-p Ripple at Two Times Line Frequency How is this supposed to be done? With a 60Hz line frequency (U.S.), is this supposed to be performed with the scope measuring the ripple triggered at 120Hz or am I misinterpreting what's being stated? Is it simply assumed that any ripple will present itself at twice the line frequency (full-wave rectification) and the scope being used to measure this will simply trigger at that frequency (assumedly using a fairly slow sweep speed to better see the waveform)? Thanks, Barry - N4BUQ |
|
Tek 7K plugins available - spring garage cleaning
Hello to all again!
Jim Reese from Dayton, Ohio?back in action. I am going through the piles of stuff and have many 7K plugins available at low prices. All have had basic function testing in a 7704A unless otherwise noted. Add shipping from zip 45344. 7A16A, $207A18, $307A26, $407B50A, $307B51A, $357B92A, $50 7B92A non-working (short on power supply line, probably bad capacitor), $25 I have many others available that I have not gotten too yet that I will post later.? Let me know of anything you are looking for. Regards, Jim |
|
Re: 2220 POST displays a large X on the screen
That looks like its intentionally generated but I pulled a 2220 out of stock and I can't get anything like it. The only calibration displays on this are the box, lines and clock delay timer adjust.
If you say it sometimes works and maybe after you replace the PSU caps you still get the X I would remove the display chip (under the round heatsink), gently clean the pins and the chip contacts and reinstall it. These chips sometimes give wacky intermittent problems if not seated well. It is very much a cut down 2230 but I'd guess it would still report memory faults etc if there were any. Your scope sounds like it is booting into digital mode for the fault. Analog comes on first, goes off, then digital mode comes on. you can confirm by putting P9104 into its reset position and powering on. ---In TekScopes@..., <stbarker123@...> wrote : HiSorry, I thought I had posted an image. I've added one to the albums: Unlike the 2221 and 2230 the 2220 doesn't have on screen cursors and CRT readout. The only character it displays is the T for the trigger and the memory bar. I'm guessing it has much simpler diagnostics/ error reporting. |
|
Re: New file uploaded to TekScopes
Hi Darren,
toggle quoted message
Show quoted text
If you upload photos to the Photos section, people can view them in their web browser rather than having to download them first. Malcolm On 30 March 2016 at 14:42, <TekScopes@...> wrote:
|
|
New file uploaded to TekScopes
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the TekScopes group. File : /2247A-PSU-BurnMark-Near-A18R2254 /After-2of2.jpg Uploaded by : darren_ting_hc <darren_ting_hc@...> Description : After Recap and burn mark fixed You can access this file at the URL: To learn more about file sharing for your group, please visit: Regards, darren_ting_hc <darren_ting_hc@...> |
|
New file uploaded to TekScopes
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the TekScopes group. File : /2247A-PSU-BurnMark-Near-A18R2254 /After-1of2.jpg Uploaded by : darren_ting_hc <darren_ting_hc@...> Description : After Recap and burn mark fixed You can access this file at the URL: To learn more about file sharing for your group, please visit: Regards, darren_ting_hc <darren_ting_hc@...> |
|
New file uploaded to TekScopes
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the TekScopes group. File : /2247A-PSU-BurnMark-Near-A18R2254 /Before-1of1.jpg Uploaded by : darren_ting_hc <darren_ting_hc@...> Description : Before Recap and burn mark fix You can access this file at the URL: To learn more about file sharing for your group, please visit: Regards, darren_ting_hc <darren_ting_hc@...> |
|
Re: 2465B U400 Availability?
I have a CRT if needed (scavenged from a 2430A with bad CCDs, no screen burn). In the UK.
toggle quoted message
Show quoted text
Dave -----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] Sent: 30 March 2016 05:01 To: TekScopes@... Subject: Re: [TekScopes] Re: 2465B U400 Availability? Its troubling that the scope ma have been dropped so hard. Double check the CRT. If all channels show similar distortion you may have a CRT fault. Its repairable though. |
|
New file uploaded to TekScopes
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the TekScopes group. File : /2247A-PSU-BurnMark-Near-A18R2254 /2247A-A18_PSU-Recap-Share-V3.xlsx Uploaded by : darren_ting_hc <darren_ting_hc@...> Description : Replacement part list used to recap my unit, run for 24 hours so far OK All ripple within specs You can access this file at the URL: To learn more about file sharing for your group, please visit: Regards, darren_ting_hc <darren_ting_hc@...> |
|
Re: 2465B U400 Availability?
Only Channels 1 and 2 exhibit vertical linearity issues. Channels 3 and 4 appear to be okay. It won't be a big deal to swap U400 with my 2445 to see if it fixes the problem.
toggle quoted message
Show quoted text
I do notice the trace is not as sharp as I'd like/expect (my 2445 shows a bit crisper and I think they use the same CRT), so not sure if there's internal damage or just needs adjusting. There's a slight dent in the bottom rear of the cabinet and I think I can tell a small distortion in one of the frame pieces that meets up with the rear panel but the direction of that distortion seems odd (e.g. it would indicate an outward force rather than an inward force such as a strike to the rear panel, etc.). No telling just what/how it was hit. Overall, the frame seems twisted about 1/8" or more (doesn't sit flat on the bench). It's probably not too difficult to straighten this out. As for the broken fan, the way the fan "shroud" is designed, it presses against the center of the fan motor and it wouldn't really take very much pressure (with the cabinet removed) to break the small plastic supports that center the motor in the frame. I plan to CA glue those back in and see how that holds up. If not, a replacement appears pretty easy to find. The fan is slightly noisier than the other style fan in my 2445. I wish it had the same style fan in this model. BTW, as I mentioned, this appears to be a 1994 manufacture date and a 65k serial number. Was this pretty close to the end of production? I've looked for serial number correlation but not finding too much on that for this model. TekWiki just says "Produced from 1984 to ?". Thanks, Barry - N4BUQ ----- Original Message -----
From: "machine guy machineguy59@... [TekScopes]" <TekScopes@...> |
|
Re: 2220 POST displays a large X on the screen
HiSorry, I thought I had posted an image. I've added one to the albums:
Unlike the 2221 and 2230 the 2220 doesn't have on screen cursors and CRT readout. The only character it displays is the T for the trigger and the memory bar. I'm guessing it has much simpler diagnostics/ error reporting. |
|
Re: 2465B U400 Availability?
Its troubling that the scope ma have been dropped so hard.? Double check the CRT.? If all channels show similar distortion you may have a CRT fault.? Its repairable though.
From: "Barry n4buq@... [TekScopes]" <TekScopes@...> To: TekScopes@... Sent: Tuesday, March 29, 2016 9:47 PM Subject: Re: [TekScopes] Re: 2465B U400 Availability? ? Got a chance to open up the 2465B tonight. Pretty clean and no obvious signs of capacitor issues (leakage, etc.). It's a 65K serial number and appears to have been made in 1994. Fan is broken. Two of the three spokes that hold the motor are broken and the blades were stuck against the back of the main frame. I managed to push those in place well enough to hold and the fan now runs; however, no telling how long it ran without that so heat damage could be a factor. Not sure, but the scope might have taken a small hit - enough to break that fan and cause the entire frame to be twisted just a tad. Reseated U400 just for fun but didn't cure the problem. Need to check voltages and ripple and possibly reseat some connectors as the controls and CRT seem to be intermittent with some apparent noise here and there. Also will want to try swapping U400 with my 2445 to see how much that cures. Neat scope! Thanks, Barry - N4BUQ ----- Original Message ----- From: "Barry n4buq@... [TekScopes]" <TekScopes@...>#yiv6820390851 #yiv6820390851 -- #yiv6820390851ygrp-mkp {border:1px solid #d8d8d8;font-family:Arial;margin:10px 0;padding:0 10px;}#yiv6820390851 #yiv6820390851ygrp-mkp hr {border:1px solid #d8d8d8;}#yiv6820390851 #yiv6820390851ygrp-mkp #yiv6820390851hd {color:#628c2a;font-size:85%;font-weight:700;line-height:122%;margin:10px 0;}#yiv6820390851 #yiv6820390851ygrp-mkp #yiv6820390851ads {margin-bottom:10px;}#yiv6820390851 #yiv6820390851ygrp-mkp .yiv6820390851ad {padding:0 0;}#yiv6820390851 #yiv6820390851ygrp-mkp .yiv6820390851ad p {margin:0;}#yiv6820390851 #yiv6820390851ygrp-mkp .yiv6820390851ad a {color:#0000ff;text-decoration:none;}#yiv6820390851 #yiv6820390851ygrp-sponsor #yiv6820390851ygrp-lc {font-family:Arial;}#yiv6820390851 #yiv6820390851ygrp-sponsor #yiv6820390851ygrp-lc #yiv6820390851hd {margin:10px 0px;font-weight:700;font-size:78%;line-height:122%;}#yiv6820390851 #yiv6820390851ygrp-sponsor #yiv6820390851ygrp-lc .yiv6820390851ad {margin-bottom:10px;padding:0 0;}#yiv6820390851 #yiv6820390851actions {font-family:Verdana;font-size:11px;padding:10px 0;}#yiv6820390851 #yiv6820390851activity {background-color:#e0ecee;float:left;font-family:Verdana;font-size:10px;padding:10px;}#yiv6820390851 #yiv6820390851activity span {font-weight:700;}#yiv6820390851 #yiv6820390851activity span:first-child {text-transform:uppercase;}#yiv6820390851 #yiv6820390851activity span a {color:#5085b6;text-decoration:none;}#yiv6820390851 #yiv6820390851activity span span {color:#ff7900;}#yiv6820390851 #yiv6820390851activity span .yiv6820390851underline {text-decoration:underline;}#yiv6820390851 .yiv6820390851attach {clear:both;display:table;font-family:Arial;font-size:12px;padding:10px 0;width:400px;}#yiv6820390851 .yiv6820390851attach div a {text-decoration:none;}#yiv6820390851 .yiv6820390851attach img {border:none;padding-right:5px;}#yiv6820390851 .yiv6820390851attach label {display:block;margin-bottom:5px;}#yiv6820390851 .yiv6820390851attach label a {text-decoration:none;}#yiv6820390851 blockquote {margin:0 0 0 4px;}#yiv6820390851 .yiv6820390851bold {font-family:Arial;font-size:13px;font-weight:700;}#yiv6820390851 .yiv6820390851bold a {text-decoration:none;}#yiv6820390851 dd.yiv6820390851last p a {font-family:Verdana;font-weight:700;}#yiv6820390851 dd.yiv6820390851last p span {margin-right:10px;font-family:Verdana;font-weight:700;}#yiv6820390851 dd.yiv6820390851last p span.yiv6820390851yshortcuts {margin-right:0;}#yiv6820390851 div.yiv6820390851attach-table div div a {text-decoration:none;}#yiv6820390851 div.yiv6820390851attach-table {width:400px;}#yiv6820390851 div.yiv6820390851file-title a, #yiv6820390851 div.yiv6820390851file-title a:active, #yiv6820390851 div.yiv6820390851file-title a:hover, #yiv6820390851 div.yiv6820390851file-title a:visited {text-decoration:none;}#yiv6820390851 div.yiv6820390851photo-title a, #yiv6820390851 div.yiv6820390851photo-title a:active, #yiv6820390851 div.yiv6820390851photo-title a:hover, #yiv6820390851 div.yiv6820390851photo-title a:visited {text-decoration:none;}#yiv6820390851 div#yiv6820390851ygrp-mlmsg #yiv6820390851ygrp-msg p a span.yiv6820390851yshortcuts {font-family:Verdana;font-size:10px;font-weight:normal;}#yiv6820390851 .yiv6820390851green {color:#628c2a;}#yiv6820390851 .yiv6820390851MsoNormal {margin:0 0 0 0;}#yiv6820390851 o {font-size:0;}#yiv6820390851 #yiv6820390851photos div {float:left;width:72px;}#yiv6820390851 #yiv6820390851photos div div {border:1px solid #666666;height:62px;overflow:hidden;width:62px;}#yiv6820390851 #yiv6820390851photos div label {color:#666666;font-size:10px;overflow:hidden;text-align:center;white-space:nowrap;width:64px;}#yiv6820390851 #yiv6820390851reco-category {font-size:77%;}#yiv6820390851 #yiv6820390851reco-desc {font-size:77%;}#yiv6820390851 .yiv6820390851replbq {margin:4px;}#yiv6820390851 #yiv6820390851ygrp-actbar div a:first-child {margin-right:2px;padding-right:5px;}#yiv6820390851 #yiv6820390851ygrp-mlmsg {font-size:13px;font-family:Arial, helvetica, clean, sans-serif;}#yiv6820390851 #yiv6820390851ygrp-mlmsg table {font-size:inherit;font:100%;}#yiv6820390851 #yiv6820390851ygrp-mlmsg select, #yiv6820390851 input, #yiv6820390851 textarea {font:99% Arial, Helvetica, clean, sans-serif;}#yiv6820390851 #yiv6820390851ygrp-mlmsg pre, #yiv6820390851 code {font:115% monospace;}#yiv6820390851 #yiv6820390851ygrp-mlmsg * {line-height:1.22em;}#yiv6820390851 #yiv6820390851ygrp-mlmsg #yiv6820390851logo {padding-bottom:10px;}#yiv6820390851 #yiv6820390851ygrp-msg p a {font-family:Verdana;}#yiv6820390851 #yiv6820390851ygrp-msg p#yiv6820390851attach-count span {color:#1E66AE;font-weight:700;}#yiv6820390851 #yiv6820390851ygrp-reco #yiv6820390851reco-head {color:#ff7900;font-weight:700;}#yiv6820390851 #yiv6820390851ygrp-reco {margin-bottom:20px;padding:0px;}#yiv6820390851 #yiv6820390851ygrp-sponsor #yiv6820390851ov li a {font-size:130%;text-decoration:none;}#yiv6820390851 #yiv6820390851ygrp-sponsor #yiv6820390851ov li {font-size:77%;list-style-type:square;padding:6px 0;}#yiv6820390851 #yiv6820390851ygrp-sponsor #yiv6820390851ov ul {margin:0;padding:0 0 0 8px;}#yiv6820390851 #yiv6820390851ygrp-text {font-family:Georgia;}#yiv6820390851 #yiv6820390851ygrp-text p {margin:0 0 1em 0;}#yiv6820390851 #yiv6820390851ygrp-text tt {font-size:120%;}#yiv6820390851 #yiv6820390851ygrp-vital ul li:last-child {border-right:none !important;}#yiv6820390851 [Non-text portions of this message have been removed] |
David Hess
Raymond Domp Frank
David C. Partridge
to navigate to use esc to dismiss