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Thank you -I obviously had an early download.
This versn is much more helpful, especially as it shows how to put the
bits back together (all those screws !!)
Thanks again.
Tim


On Mon, 17 Mar 2025 at 23:14, Ke-Fong Lin via groups.io <anotherlin=
[email protected]> wrote:

Hi,

The manual doesn't look like the "interim" one:



They've updated the pdf file I guess.
I also have the pdf from Artek, it looks identical.

Best regards,

I guess a simple explanation would be that the higher the accelerating voltage is, the faster the electrons go from the gun to the screen, and spend less time passing the deflection plates, therefore the deflection plates have less influence in changing the direction of the electrons. So the higher the EHT voltage, the lesser the deflection is

<Space>
John

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.

I remember frying some diodes during lunch on a brand new 575 in a class. Teacher walked by and said what are you doing? I and classmate said burning up some diodes. Good, good, he said, knowing we were learning. Try some sacrificial junctions. Turn up the drive and see huge loops from the heating.

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!!

Well... Not a cleaning problem. Actually a broken actuator inside the "CH1V" switch section, it was the internal actuator position that was unreliable, not intermittent contacts. So, it will be full replacement of the switch assembly. Fortunately I found one and have it coming.
I desoldered and removed the A14 "Hot Signal Switch" circuit board from the top of the switch module. Tedious work but doable with careful heat application and copious use of solder wick. The switch module itself will take more time...
As Roseanne Rosannadanna said, "it's always something..."

Hi Sigur?ur,

Option 9 includes option 6. IIRC you bring up the CTT menu with the A/B
TRIG/MENU button.

Yes, but according to the manual,should have a different designation, not "A/B TRIG" but "A/B MENU", also B TRIG options seems different.
It is almost impossible to tell if there is a different designation but the description say it should be different. Seems not.
Do you have a A/B TRIG MENU label near the button or simply A/B TRIG? Looking on the net never saw an image with A/B TRIG MENU label.


This is an image(awful) of the manual:


This is the closeup of that part of my front panel:


Anyway, I will try to activate the function to see if it works, simply pressing the A/B Trig won't work, probably I need something connected.

This is a purely analog scope, the only place the trace exists is on the
CRT.

I know, but having a HP-1500L ESA Spectrun analyzer that was able to send you the screen...I was hoping that. Not worth the hassle then, I agree.

--
Giuseppe Marullo
IW2JWW - JN45RQ

Hi again.

To finish off this thread.

For whatever reason, the 'spare' CRT damaged the video board, revealing that the CRT is dead and may well have been why the 2nd 492 had been stripped down so much.

In the end I didn't open up the YIG, as I was unable to locate any clear images so I focused on the LV rails (which is where I should have started in the first place). The +9v rail was reading +1.26v and the +9v rail 2A fuse was open.
One thing that had also changed following the failed CRT test was that the scale illumination no longer worked.
Swapping around the multi-pin illumination connector situated behind the CRT bezel resolved that problem, resolved the blown fuse and also resolved the lack of vertical deflection.

With the unit fixed and working again, I packed the SA away and have now passed it on.


The End.



James

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

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.

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.

Hi,

The manual doesn't look like the "interim" one:



They've updated the pdf file I guess.
I also have the pdf from Artek, it looks identical.

Best regards,

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

It’s the effect of internal capacitance in the device and/or heating/cooling of the semiconductor junction.

Dave: I will make another round of them. April 5th is not far off but it's possible they could be ready for purchase then.

-Thomas

Thomas!

I will be visiting the museum on April 5th!!! Is there any chance you can save me one?!?!?

- Dave KQ4VBE

Thanks Alex,
1) could you please confirm that your 2465B has a low serial?
If so you should have performed the battery mod, else it should fail the battery voltage check, right?

I saw that the original creator of the read utility had a 2465B low serial, so hopefully the FRAM mod is doable also on that model.

2) Could you be so kind and send me *exact* Mouse BOM for it?

and prices had skyrocketed to something over $63 (!)

I saw the FRAM adapter and yes, probably ARIES got acquired by Cartier.

I could buy the GQ4X4 + eraser, I don't have much use of it but it is something I always wanted to buy, you never know. It seems pretty decent for the price, don't see many alternatives in that price range with the confirmed ability to deal with FRAMs.

Thanks a lot.

--
Giuseppe Marullo
IW2JWW - JN45RQ

Hi,
Can anyone explain why my Tektronix shows double curves in each step when I testing transistors?
thank you!
/g/TekScopes/album?id=301335

Perfect. I sent you my SN info directly, hope it helps.