The Tektronix 2440 series was an excellent fault finding adventure and now you take on another Tektronix scope. Thank you for making these repair videos! Quite a cliffhanger at the end of this one though ;-)
I just purchased a 2445a from an instrument dealer here in the US. It will be completely refurbished and calibrated before it is shipped. I just repaired a 2236 Tek scope which I bought off eBay for $50. They can be tough to work on, very compact scopes. I felt it was worth the extra money to get the 2245a professionally calibrated, so I have a known standard in my lab.
Hi Simon. One of my subscribers told me to check out your channel. Even though I previously recognised you as a long-term subscriber to my channel, I totally missed the Simon Spiers Show. That's a shame. It is wonderful. I've subscribed right now. Thumbs up!
I agree with you. Lose that mechanical connection briefly and you will really be hosed. I have done this before on the earlier 2465's using a tabbed coin cell with series R as a backup and I always solder direct to the circuit trace. Also be certain your iron doesn't provide a low resistance path to ground as well, if you use the solder in backup method.
The grounded soldering iron tip is not an issue. While it's true that most (good) irons have the tip connected to mains earth (ground) for safety purposes. The DC power supply providing the backup power is isolated from mains earth (ground) via it's step down transformer this is called galvanic isolation. So you can safely touch the + or - terminal of the power supply with the earthed iron tip and not cause a short circuit. This is because the DC supply is not mains earth (ground) referenced and current can't flow. In other words the only place current can flow (there is a complete circuit) is between the + and - terminals of the power supply. One thing to be aware of is where your solder wire is and make sure you don't accidentally short VCC and GND. Since lets face it most of us are used to soldering with the equipment powered off and don't give it a second thought.
Kerry Wong, but are fraught with danger. It seems there's a proprietary chip on the top board that goes out with age and is not available. Once lost, the scope is useless.
The unit works well. I did loose the ram, so had to do a full recal again. Very time consuming. Used it last week but tend to use a digital scope (2440) mainly.
Phooey! Have to wait for next video to find out the result! ;-) I have to figure out what the battery is in my 2440 as I'm sure by now it's in dire need of replacement (do you remember what it was by any chance when you were redoing yours?)
It might not working after that lol...It like computer, you dont need to supply a power while u replacing a backup battery...worst case scenario is your setting is gone, but not the initial setup of the scope...it will still booting up. Put a live voltage into the circuit while soldering is not a good idea...
Hello, nice job! Did it work, or did you have to recalibrate the scope? I have the same scope and I need to change the battery. But I don't want the data get lost.
My battery had been dead for some time and had lost calibration years ago. Connect a temporary supply up while changing it. A couple of aa batteries in series should hold the data.
The Tektronix 2440 series was an excellent fault finding adventure and now you take on another Tektronix scope. Thank you for making these repair videos! Quite a cliffhanger at the end of this one though ;-)
I just purchased a 2445a from an instrument dealer here in the US. It will be completely refurbished and calibrated before it is shipped. I just repaired a 2236 Tek scope which I bought off eBay for $50. They can be tough to work on, very compact scopes. I felt it was worth the extra money to get the 2245a professionally calibrated, so I have a known standard in my lab.
Hi Simon. One of my subscribers told me to check out your channel. Even though I previously recognised you as a long-term subscriber to my channel, I totally missed the Simon Spiers Show. That's a shame. It is wonderful. I've subscribed right now. Thumbs up!
Ing. Max Koschuh Cheers Max!
I had my heart in my mouth thinking those crocodile clips backing up the memory were going to fall off. Nice job Simon regards Chris
I agree with you. Lose that mechanical connection briefly and you will really be hosed. I have done this before on the earlier 2465's using a tabbed coin cell with series R as a backup and I always solder direct to the circuit trace. Also be certain your iron doesn't provide a low resistance path to ground as well, if you use the solder in backup method.
The grounded soldering iron tip is not an issue. While it's true that most (good) irons have the tip connected to mains earth (ground) for safety purposes.
The DC power supply providing the backup power is isolated from mains earth (ground) via it's step down transformer this is called galvanic isolation. So you can safely touch the + or - terminal of the power supply with the earthed iron tip and not cause a short circuit. This is because the DC supply is not mains earth (ground) referenced and current can't flow. In other words the only place current can flow (there is a complete circuit) is between the + and - terminals of the power supply.
One thing to be aware of is where your solder wire is and make sure you don't accidentally short VCC and GND. Since lets face it most of us are used to soldering with the equipment powered off and don't give it a second thought.
It has been used several times and loved.
Good luck with your repair effort! I have both 2445 and 2465 (not the "a" version though) and these are excellent scopes.
Kerry Wong, but are fraught with danger. It seems there's a proprietary chip on the top board that goes out with age and is not available. Once lost, the scope is useless.
Hi sir. Can you named good battery replacement? Link store. How to know when is time for.replacement. i know if battery died all call be lost...
Nice video on the RAM battery change. Whatever happened to this machine? Fix the error? Retain the RAM?
The unit works well. I did loose the ram, so had to do a full recal again. Very time consuming. Used it last week but tend to use a digital scope (2440) mainly.
it is not a good idea to place the new battery on the metal countertop, by doing so you are shorting its terminals
Phooey! Have to wait for next video to find out the result! ;-) I have to figure out what the battery is in my 2440 as I'm sure by now it's in dire need of replacement (do you remember what it was by any chance when you were redoing yours?)
It might not working after that lol...It like computer, you dont need to supply a power while u replacing a backup battery...worst case scenario is your setting is gone, but not the initial setup of the scope...it will still booting up. Put a live voltage into the circuit while soldering is not a good idea...
Please pull the protective film off your multimeter screen!
Roger Onslow haha. Yes lots of people get annoyed with that. Shan't!
Haha.. I still have the film on my 20 year old Fluke. Been tempted to pull it off but it's still "protecting".
Hello, nice job! Did it work, or did you have to recalibrate the scope? I have the same scope and I need to change the battery. But I don't want the data get lost.
My battery had been dead for some time and had lost calibration years ago. Connect a temporary supply up while changing it. A couple of aa batteries in series should hold the data.
@@SoddingaboutSi how to know is dead? How to see healthy is?