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I bought a no error codes on startup S/N B057443. Inspection of A5 showed no leaking of the SMD eCaps, but the Dallas DS1225Y was 1991 vintage by date code. I bought a new Dallas DS1225AB-200+ from Mouser. Desoldered the old SRAM with a Hakko 472D uneventfully, placed a TE Connectivity 1-2199299-2 28P DIP SKT 600 CL LADDER socket and soldered it in place without drama. Good looking solder joints. I was able to read the 1991 DS1225Y with the GQ-4x4 programmer and saved the data to a .bin file. I wrote and verified the .bin file to the 2023 “new” DS1225AB-200+ SRAM. Placed it carefully and correctly into the sock, and now have the 04 Fail error. Same thing with the old 1991 SRAM.
I read the old and new SRAM data sets after trying startup, both sets of data were significantly changed. Bad solder joints?
I ohm-checked the SRAM socket pins to the A5 board connections, listed below. The lowest resistance I found was a few .02Ω, most common was about .2Ω and the highest was .53Ω. Seems higher than I’d like in general. Normal?
Tek 2465B Late A5 U2460 Pin Connections
U2460
Pin Descriptor Component Pin
1 U2250 15
2 BA12 U2160 3
3 BA7 " 4
4 BA6 " 5
5 BA5 " 6
6 BA4 " 7
7 BA3 " 8
8 BA2 " 9
9 BA1 " 10
10 BA0 " 11
11 BD0 J4241 29
12 BD1 " 27
13 BD2 " 25
14 - " -
15 BD3 " 23
16 BD4 " 28
17 BD5 " 24
18 BD6 " 22
19 BD7 " 20
20 U2250 11
21 BA10 U2160 24
22 " 25
23 BA11 " 27
24 BA9 " 28
25 BA8 " 29
26 U2250 19
27 J512 23
I’m at a loss what to do going forward. Any help would be appreciated.
Thanks, Ron
AF5IV
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Ron,
Try this exercise to see if this clears up your issue. Its a specific button push in the correct sequence.
CYCLE ERROR CLEAR (Exerciser 03). This routine
provides a way for the operator to clear the cycle-failure
data written to the RAM when a CYCLE mode failure
occurs. Interpretation of the cycle failure data is explained
in the "Display Format" description provided earlier in this
section. Until the data is cleared, each time the
instrument is powered up, the Diagnostic Monitor is
entered.
Clearing the RAM location (and the CYCLE ERROR
message) is done by scrolling to EXER 03 (CLEAR CYCLE
ERROR) and pressing the following switches in sequence:
TRIGGER COUPLING upper (starts exerciser),
TRIGGER SOURCE lower,
TRIGGER MODE lower, then
TRIGGER COUPLING lower (exits the exerciser).
When the CYCLE ERROR CLEAR routine is successfully
executed, the cycle failure data will disappear from
the display.
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May not be related but I had a lot of trouble with the GQ-4x4 and my 2467B when replacing the Dallas chip. I went with the GQ since I watched a YouTube vid where someone used one successfully with a Tek scope. I wrote to GQ support and the suspected a defective programmer and wanted me to send it in. I returned it to Amazon, didn't want to waste weeks. I ended up buying an XGECU T48 and it worked fine.
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Craig, no joy with the EXER 03 sequence, tried it a couple times. Same error - 04 Fail. I did notice when I clear by pressing A/B TRIG, I get 4 CRT lines and gibberish on the bottom of the screen.
pac1085, I may have to try another programmer. Do you see any need to buy $10+ worth of accessory boards and widgets?
Specific questions:
Are those resistances in the socket connections acceptable? In other words, should I reheat the the solder joints?
Thx, Ron
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Not sure what you mean regarding the accessory boards/widgets. This is the exact package I bought:
I bought the one with the extras since I wanted them for other things in the future, retro pcs etc, but none of them are needed for this purpose.
You never attempted to write the original Dallas chip right? Just read it once?
Somewhere on eevblog (and maybe in this group) people have posted their bin files, you can restore someone else's 2464B cal data to your new Dallas chip just to validate functionality/rule out the read from your old chip. I've seen posts from other people on forums of their old chips losing their data after being desoldered.
Good luck!!
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Ron,
Well I have used my GQ4x4 for many years and it works fine for me. But you shouldn't have to keep heating your solder joints if you had quick solder flow on each pin. Seems strange that the original NVRAM that was ok when you unsoldered doesn't work but It could have gotten messed up in the process. Can you just go beyond the error and get a normal display? Review the resistor ladder circuits with your ohm meter ahead of the DAC chip.
I know this may not be helpful, in years past I used to send all my A5’s to QService for repair and probably over 50% of the NVRAM chips he tried to copy he couldn't get data saved, he is very qualified in repair of these modules. But now I do the work myself and I haven't had an issue saving and reprogramming data. But I also replace caps and any other resistors needed to correct ladder circuit. So it’s probably not your programmer.
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pac1085, I copied the original 1991 SRAM data to buffer, then put it on the new SRAM. That generated the 04 Fail. I then put the 1991 SRAM back in the A5, it also failed. The data had been changed on the SRAM in both cases. I rewrote the data back to what it was when the original 1991 SRAM was initially removed, put it in the 2465b and the result was another 04 Fail and another overwrite by the DUT.
I have the .bin data from a Qservice generic “startup” 2465b SRAM. I can certainly try that.
Craig, “Can you just go beyond the error and get a normal display?”
I get 4 CRT lines and gibberish on the bottom of the screen. Can you explain to me where on the schemtic “resistor ladder circuits with your ohm meter ahead of the DAC chip” is?
Thx, Ron
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That’s awesome, Craig! Greatly appreciated. I was thinking it was U2550 on schematic <1>, like a dope. I’ll run through it later tonight.
Thx, Ron
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Craig, all pinouts of U2101 have intact connection to the next component and the resistor ladder resistors ohm correctly including connection to +10V Ref. The C2010 measures 15.8 ?F.
pac085, I received an Amazon XGPro T48. Doesn’t seem to work at all. Version 12.75 software reads everything FF, says it PROG’s - nothing written. v12.85 software only gives programmer not connected. Not a fan.
I copied the Qservice startup .bin file and did start up; it’s a little different result. I still have a Test 04 error, but when cleared with A/B only two trace lines, but no gibberish on readout.
Thx, Ron
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Ron,
Ok now try to clear 04 diagnostic with
EXER 3 as described in other post I sent. Calibration may need to be done if values aren’t correct.
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Craig, I tried TEK2465B Serial B066505 EAROM.BIN from the groups.io website, and the unit powered up without Test 04 Fail! Only two traces and a few extra question marks on the readout, though. I reloaded the original read of the Dallas DS1225Y SRAM, and was back to 4 traces but with many question marks on the readout. Per your suggestion, I went through the EXER 03 procedure using the original DS1225 read SRAM. I was then able to get out of diagnostic mode, but upon power-up, I’m back in it again with Test 04 Fail.
My interpretation of all this is that the original read was somehow corrupted, and the unit is functioning. Which means I should have photographed the SRAM data pages.
I recently recapped a Tek TM503 and have another working 2565B. I also have supposedly working PG506 and TM501 generators, as well as a WaveTek 145 & a 191 Pulse Generator. I guess I get to learn how to calibrate, unless you have another suggestion.
Thx, Ron
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Ron,
Well the question marks are definite need for calibration. It is a very time consuming process which will take several hours. Like spending all day on Saturday without any distractions. The directions are kinda intimidating as to what the person that wrote it means in some of it. So read directions carefully. It not uncommon to have some tests fail and that adds to discouragement. But take your time and you will get thru it. Each section must be completed without errors or it won’t save to move onto next procedure.
You need basically most of what is on Table 4-1 in the service manual to get thru it. So review that list and read procedure before starting.
Craig
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Craig,
I think I have most of the equipment listed are either in the Tek service manual or the Tek-derived US Army service manual, TM-09078B-40/2, which gives non-Tek equipment-alternatives like the WaveTek’s listed below. I may have to scrabble for a couple of the attenuators or what-not but hopefully I can work my way through it. Thanks for your help!
Ron
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Ron,
Good to hear you have the required equipment.
Where did you come up with the Tek-derived US Army service manual, TM-09078B-40/2? I haven't seen one for the 2465B.
Craig
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Craig, here’s one link:
Ron
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On Thu, Mar 20, 2025 at 06:54 PM, Craig Cramb wrote:
Where did you come up with the Tek-derived US Army service manual
It's on Tekwiki, at least it is there now. -- Roy Thistle
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On Friday, March 21, 2025 at 06:57:58 PM PDT, Roy Thistle via groups.io <roy.thistle@...> wrote: On Thu, Mar 20, 2025 at 06:54 PM, Craig Cramb wrote:
Where did you come up with the Tek-derived US Army service manual
It's on Tekwiki, at least it is there now. -- Roy Thistle
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Craig Cramb