Date
1 - 12 of 12
Tek 2430 saga (was RE: [TekScopes] ebay scammers to be aware of)
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Dave Voorhis
Update on the infamous (?) 2430...
I removed the 18650 and installed the LTC cell. That went fine. I set up a fan to blow on the hybrids and went through the self-calibration and external calibration procedures, the latter using DC voltages supplied by a good (enough) bench supply and a good (enough) bench DVM. That went fine. I popped the calibration jumper back on (it prevents users from engaging external calibration via the front panel) and installed the case. That went fine. Fired it up... The self-test failed with epic levels of fail. Now the self diag shows almost exactly, if not exactly, the same failures seen here: https://groups.io/g/TekScopes/topic/tektronix_2430/7648796 I removed the case to verify I hadn't inadvertently snagged a ribbon cable, or the EMI shielding stuff hadn't popped out and shorted something, or similar. It hadn't. No obvious technician error, other than I noted afterward that the external calibration is supposed to be done with the case on. Though now even the self-calibration fails. I haven't had a chance to do any further diagnostics. I'm guessing the sudden transition from Go to No indicates some component failure. Anyone seen that before?
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Hi,
It may be related with the order of "putting the jumper back" and the "power down of the scope". I had something similar, but can't remember right now.. Have to find and look in my notes. Leo
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Siggi
My 2430 needed repeated COLD STARTs before these errors cleared after a
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battery repair & replacement.
On Mon, Jan 17, 2022 at 10:14 AM Dave Voorhis <voorhis@gmail.com> wrote:
Update on the infamous (?) 2430...
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Dave Voorhis
Interesting.
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I did only one COLD START after it went into failure mode. I made multiple attempts at self-calibration. They failed the same way every time. I made several attempts at external calibration. I couldn't get them to pass, probably because the self-calibration failed. The only fixes I'd done was replace the battery, clean up the grease (!), and fix a bezel button switch, and although it worked correctly afterward it seemed likely that the subsequent failure might have been related to changing the battery, so I re-examined all connections on the two top circuit boards. I found a loose flake of solder, presumably from some previous repair. It might have floated into a bad place. I also picked up the chassis and shook it in various orientations, in case there was a loose screw or other conductive detritus inside. Something fell out; not sure what as it bounced away. I set up the fan and turned it on. This time I was able to run and pass the self-calibration and the external calibration. The REPET self-calibration needing doing after the COLD START. It passed. I reinstalled the J159 calibration lock jumper and it started up fine. After multiple restarts, it seemed fine. I put the case back on -- very carefully, in case I shorted something against the cabinet the first time around. It works, and all seems fine now. I need to thoroughly test all the functionality, but so far it seems to be behaving.
-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Siggi via groups.io Sent: 17 January 2022 17:19 To: TekScopes@groups.io Subject: Re: Tek 2430 saga (was RE: [TekScopes] ebay scammers to be aware of) My 2430 needed repeated COLD STARTs before these errors cleared after a battery repair & replacement. On Mon, Jan 17, 2022 at 10:14 AM Dave Voorhis <voorhis@gmail.com> wrote: Update on the infamous (?) 2430...
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Vince Vielhaber
On my 2440A I had to do a number of cold starts before doing the cal. Not knowing that in advance I had to do the cal more than once. It seems removing the battery and replacing it leaves some odd states in memory that need to be reset by the cold start. At least that's how I remember it.
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Vince.
On 01/17/2022 03:24 PM, Dave Voorhis wrote:
Interesting.
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Szabolcs Szigeti
Hi,
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I'm not sure about the 2430, I sold mine some time ago, but the 2440 can fail self cal if the internal adjustmens for the ccd clocks are not optimal. As far as I recall, the 2430 has less internal setting (as in turning potentiometers) but there is still a couple. The screen geometry and gain setting are not important from this respect, but still useful to do, they can drift with time. Szabolcs Dave Voorhis <voorhis@gmail.com> ezt írta (időpont: 2022. jan. 17., H, 16:14):
Update on the infamous (?) 2430...
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Roger Evans
If you read some of the threads on eevblog relating to the seller's previous repairs you may find an explanation for conducting foreign objects inside your scope.
Glad you have it sorted! Regards, Roger
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On Mon, Jan 17, 2022 at 04:14 PM, Dave Voorhis wrote:
Not quite true. There is a "secret" sequence you can use to enable calibration without moving the jumper. On 2430 non A press these in sequence: ATT, TRIG, ADJ, ATT and the calibration routines are enabled. 2430A has a similar sequence but not exactly the same. Unfortunately I can't recall it exactly but possibly just one more pressed button. /Håkan
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Roy Thistle
On Mon, Jan 17, 2022 at 12:24 PM, Dave Voorhis wrote:
In some other post, I was suggesting that these restarts are necessary because of the particular technology of LTC cells. Modern? LTC cells may need appropriate 'conditioning' before the cell stabilises. What are the causes necessitating these restarts? And, what effect (if any) do they have on the scope? -- Roy Thistle
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Dave Voorhis
Sorry, I wasn't clear.
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The steps were this: 0. I received the unit in unknown condition but advised that it was functioning. I turned it on. 1. Scope showed 'UNCAL'. I turned it off and removed the case. I repaired a bezel switch and cleaned off what appeared to be general-purpose grease (e.g., for bicycle wheel bearings, etc.) smeared inside the case. 2. I turned it on to verify that the switch now worked, and to verify that other than being 'UNCAL' the 'scope essentially worked. I turned it off. 2. I removed an 18650 battery and installed a correct LTC backup cell, both (very) briefly in parallel to avoid loss of existing settings. 3. I removed the calibration lock jumper to permit calibration. 4. I successfully performed self-calibration and external calibration. 5. I turned the 'scope on and off multiple times, each time verifying that it self-tested and worked normally. 6. I reinstalled the calibration lock jumper and installed the case. 7. On startup, the self-test failed. Multiple startup attempts indicated the same failures each time. 8. I removed the case and the calibration lock jumper. 9. Both self-calibrate and external calibration failed. 10. I did a COLD START. 11. Both self-calibrate and external calibration failed. 12. I removed the top boards (removed previously to install the backup cell), inspected them, re-installed them, reseated the connections on the top boards, removed a small flake of solder resting on the top board near the case grounding tab, and tipped out some unknown loose object. 13. I started the 'scope; self-test showed FAIL. 14. I successfully performed self-calibration and external calibration. 15. I reinstalled the calibration lock jumper and installed the case. I turned it on and self-tests passed. It has subsequently behaved normally, through multiple on/off cycles, without indication of any problems. That's what I meant by, "After multiple restarts, it seemed fine." In other words, it appears to now be working correctly. Apologies for causing confusion!
-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Roy Thistle Sent: 18 January 2022 05:34 To: TekScopes@groups.io Subject: Re: Tek 2430 saga (was RE: [TekScopes] ebay scammers to be aware of) On Mon, Jan 17, 2022 at 12:24 PM, Dave Voorhis wrote: In some other post, I was suggesting that these restarts are necessary because of the particular technology of LTC cells. Modern? LTC cells may need appropriate 'conditioning' before the cell stabilises. What are the causes necessitating these restarts? And, what effect (if any) do they have on the scope? -- Roy Thistle
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Dave Voorhis
Excellent! Thanks for the tip.
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Only... I don't know what you mean by "ATT, TRIG, ADJ, ATT." If it's buttons, that doesn't correspond -- at least, not unambiguously -- to the labels on the buttons on the panel. If it's menu items, which menu? This will be helpful when I build a 200mv, 500mv, 2v, 20v DC calibrator. I successfully calibrated the unit with a DVM and bench supply, but it was rather crude, slightly drifty, and not very accurate. Sufficient to get the 'scope working, obviously, but could be much better.
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From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of zenith5106 via groups.io Sent: 18 January 2022 00:02 To: TekScopes@groups.io Subject: Re: Tek 2430 saga (was RE: [TekScopes] ebay scammers to be aware of) On Mon, Jan 17, 2022 at 04:14 PM, Dave Voorhis wrote: Not quite true. There is a "secret" sequence you can use to enable calibration without moving the jumper. On 2430 non A press these in sequence: ATT, TRIG, ADJ, ATT and the calibration routines are enabled. 2430A has a similar sequence but not exactly the same. Unfortunately I can't recall it exactly but possibly just one more pressed button. /Håkan
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Dave Voorhis
Oh, wait -- I get it. It's the Ext Cal menu items. ATTEN, TRIGGER, ADJUSTS, ATTEN.
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-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Dave Voorhis via groups.io Sent: 18 January 2022 10:24 To: TekScopes@groups.io Subject: Re: Tek 2430 saga (was RE: [TekScopes] ebay scammers to be aware of) Excellent! Thanks for the tip. Only... I don't know what you mean by "ATT, TRIG, ADJ, ATT." If it's buttons, that doesn't correspond -- at least, not unambiguously -- to the labels on the buttons on the panel. If it's menu items, which menu? This will be helpful when I build a 200mv, 500mv, 2v, 20v DC calibrator. I successfully calibrated the unit with a DVM and bench supply, but it was rather crude, slightly drifty, and not very accurate. Sufficient to get the 'scope working, obviously, but could be much better. -----Original Message----- From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of zenith5106 via groups.io Sent: 18 January 2022 00:02 To: TekScopes@groups.io Subject: Re: Tek 2430 saga (was RE: [TekScopes] ebay scammers to be aware of) On Mon, Jan 17, 2022 at 04:14 PM, Dave Voorhis wrote: Not quite true. There is a "secret" sequence you can use to enable calibration without moving the jumper. On 2430 non A press these in sequence: ATT, TRIG, ADJ, ATT and the calibration routines are enabled. 2430A has a similar sequence but not exactly the same. Unfortunately I can't recall it exactly but possibly just one more pressed button. /Håkan
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