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CLA Clean Lube adjust all controls, switches

J

Benjamin,

I swapped U2170 from an SC502. The SC502 still works and the SC504 is still not working.

Barry

Benjamin

Thank you Benjamin!

I had already tested the U2170 and it tested good for logic. I will replace it and see.

Barry

You might want to verify that U2170 is working. It is a JK flip-flop and it's in charge of channel switching. I have an SC502 that had this issue with channel switching and replacing that IC fixed it.

Benjamin

Unfortunately I can't do anything with GBIP because it won't boot.

Okay, that calms me down. But there has to be something on it. Maybe someone made a copy of their NVRAM from a TDS 520. I think that's why it doesn't boot.

Greetings!

I am working on restoring an SC504. It is cosmetically perfect, but has other issues.

Channel selection is not working. Channel 2 is always selected. The vertical positioning is also not working. I have experienced different symptoms over the last few days. Channel 1 would move both traces while Channel 2 functioned properly.

At this moment Channel 2 is displayed regardless of the channel selector. Channel 1 is not displaying at all.

Any ideas?

Hey Paul,

From what I understand, there's no critical data in the NVRAM on the
TDS5/6/700s. It's just settings and e.g. the results of SPC. If you had
options installed, then they can be reinstalled through GPIB.

Siggi

On Sat, Feb 1, 2025 at 9:22?AM Paul via groups.io <barpa97=
[email protected]> wrote:

Today I took a look at the DALLAS DS1245Y-120 NVRAM. As far as I can tell,
the battery is empty and all data is gone. :( I tried reading it out with
Xgpro. Only AA AA AA are displayed throughout.

Does anyone have an idea where I can get the data for the NVRAM?

Hi all,
An update at last. I have replaced the last of the tantalums and upgraded the aluminium electrolytics where they indicated in the manual. Wow, there's a lot of pot-holing to do getting these things to bits! The interface board is a curious piece of design...I gave it a good clean up with copious amounts of IPA, had the screen out and gave the HT lead a thorough clean up to the silicone entry plug on the CRT which had already been silicone greased, and tried to remove the carbon and grime above the PSU area, so much so that I removed some of the printing on the chassis at the same time. Then I went back to the PSU and cleaned the cap multiplier area thoroughly.

I was going to swap the cap multiplier at this point but then thought; I don't know it the spare one works, at least this one does. When re-assembled, the scope may not function and with so many variables at play I will likely need to go back in and swap out the cap multiplier again just to get it to "known good enough" in order to bug-check it, then possibly its still the cap multiplier so back in again, and so on. Also maybe, just maybe, the issue turns out to be arcing in the dirty HV box and so would now be cured? If so, no more dis-assembly, and if not cured then one more. So I re-assembled, double checked, crossed my fingers, and threw the switch. A couple of glitches later (mostly involving those wretched replacement Molex connectors which I cannot get to hold the original sockets firmly in place) it came to life. A quick check and tweak of the PSU trimpots and the voltages are all spot on, everything working fine. Yay!!

Except the PSU crackling is back, after about half an hour, like before. Argh, back in I will go, looks like you were right G?ran.

Today I took a look at the DALLAS DS1245Y-120 NVRAM. As far as I can tell, the battery is empty and all data is gone. :( I tried reading it out with Xgpro. Only AA AA AA are displayed throughout.

Does anyone have an idea where I can get the data for the NVRAM?

On Fri, Jan 31, 2025 at 8:04?PM NEIL YUENGER via groups.io <nyuenger=
[email protected]> wrote:

Just to confirm, on this image
/g/TekScopes/photo/300382/3881289?p=Created%2C%2C%2C20%2C2%2C0%2C0
,
is the 50 ohm resistor number 1? (top left) Do you know what the component
marked number 2 is?

No, I don?t believe so. I believe the 50Ohm resistor hugs the left-hand
side of that picture. You can see it's been laser trimmed.
Component marked 2 is the AC coupling capacitor.

Either way, I cannot measure 50 ohms on my BNC. So perhaps the resistor is
open, or perhaps the relay contact is not making connection.

But do you then measure 1MOhm? As many have pointed out, this should be the
default DC resistance of the attenuator, and by your description, for
reasons I mention in my earlier post, I believe your attenuator is stuck in
AC coupling.

There are no new floppy disks, they've not been made in decades. You'd have bought some ancient stock.

Heads may need cleaned , if belt drive then may be slipping.

Gotek is the modern alternative, pretends to be a floppy using a usb stick

Thanks Jon!

Thanks Siggi for your response,
Just to confirm, on this image /g/TekScopes/photo/300382/3881289?p=Created%2C%2C%2C20%2C2%2C0%2C0 ,
is the 50 ohm resistor number 1? (top left) Do you know what the component marked number 2 is?

Either way, I cannot measure 50 ohms on my BNC. So perhaps the resistor is open, or perhaps the relay contact is not making connection.

Next time that I open up the scope I will play around with the relays.

And as has been mentioned in this thread, I will study the cleaning methods for this attenuator elsewhere in this forum.

Cheers!
Neil

Thank you for the info. I have a PENTIUM II pc and it formatted the 720k disks, but I got a new error message.
"FD WRITE ERROR" and "FD READ ERROR" I'll try formatting the floppies again... and let you know.
Has anyone tried to use an emulator for the 370A and which one do you recommend ?
William

My TG501 at 1nS with a 7s14

/g/TekScopes/photo/300311/3881197?p=Created%2C%2C%2C20%2C0%2C0%2C0

Hi William,

I remember having had similar problems on a Tek AM700. It has a slimline 3" Floppy. It *did* format the floppy, but was unable to read or write. Tried different drives. It worked only when formatting the floppy outside the unit on a very old Mac (running MacOS 8).

Here is the thread:


cheers
Martin

I'm trying to format a MFD-2DD floppy on a 370A . press 'FAST/SHIFT' screen says... press 'SAVE' I press 'SAVE' and then the 370A displays ' FORMAT BUSY' goes about formatting the floppy 1 to 80 . The floppy drive light turns on during formatting as would be expected.
When it gets to 80 , the display screen ' FORMAT ERROR. ' I have tried multiple 1.44 MB floppies as well : old ones and new ones.
I bought a low density floppy from AMAZON as well with the same errors .
I get the same results, 'FORMAT ERROR' once the 370A gets to track 80. Has anyone ever experienced this problem ? Is it a bad drive ?
I'm new to the equipment. It was gifted to the school where I am the lab assistant. Any help would be appreciated.

William Foley

Thanks Jon. Fortunately the controls on my 7L5 are in good shape, and I am careful with them. After years of looking for the option 25 kit or a complete set I have kind of given up. I was hoping someone had figured out another solution.