NOTE: This was going to be part of a repair video, and it's been available to supporters for many days now. But it's only failed once since I took the cover off to investigate and hasn't failed since. If it ain't broke I can't fix it, so here is the video anyway.
Ha. This kind of bugs is the worst. Those pesky little buggers bug you, but when you get round to pinning them down, they run like cockroaches after turning the light on. I once had a Tascam DJ mixer in for repair in a field setting and didn't even have a multimeter on me, let alone a scope. A few pros . Basically, a soldermask was damaged under one of the slider pots, and a power trace had an intermittent short to GND, resulting in the mixer going haywire.
That could actually point to a thermally related (intermittent) failure. Have you had a look with the thermal camera? Maybe some component just gets too hot with the cover on or some electrolytic is going bad.
I once tried to repair a stereo amplifier where one channel would randomly start outputting max volume for a few seconds. It did that all the time, like every few minutes in normal operation. But it would never do that when I had the cover off, so I couldn't debug it. So frustrating! I was never able to fix it.
Intermittent faults are the worst. In my day we used freeze spray and cheap ass hairdryers (no cheap hot air stations then) to trigger and confirm faults with semiconductors quite quickly. This is obviously after percussive diagnostics failed to trigger the fault condition.
Considering that it's now been running for 2 days straight with the lid off and has only failed once now that I have seen, I don't like my chances of being able to diagnose it any time soon, so yeah!
@@EEVblog2 For me it was an empty memory battery on the digital board. U2, a Dallas (typical!) DS1236 with one of its key features being "Halts and restarts an out-of-control microprocessor" doesn't seem to like empty batteries
@@reps Thanks, will check it out. My first check would have been the PSU, and then monitoring the rails and triggering off the CPU reset line which would capture this if that was the case. Actually, the battery would have been part of the rail checks. Haven't done anything yet, just waiting for the damn thing to die again.
We have a large number of 2400s at work and they are starting to succumb to age with PSU faults like this. Had a few that randomly blow the fuse on the mains plug (UK so fused plug)
Perhaps a cold solder joint, flaky connector, or flaky cap? Some of these 2400s can get up there in age, think they were first released in 1992! If you plan on keeping it, recapping the PSU/digital stuff and a little contact cleaner/deoxit on the interconnects couldn't hurt either. Plus the internal system battery and the fan could always use a refresher after many years and hours.
Need a Ghostbusters. In late 70's, the game manufacturer said replace the DACs. If that does not fix the problem, put the board on the floor and drive a forklift over it and replace everything that breaks!
I had the exact the same thing. Most likely the mechanical power switch which gets some serious mechanical torque from the front switch which is just a long white plastic rod which goes all the way back. This torque breaks the solder joint of the switch. I just soldered the power leads directly to the PCB bypassing the switch. Add an external switch to the cable or use the cable as switch and you are set. It was a relatively easy fix. While you are in the unit, change the battery as well since it can give symptoms which are similar. Also, make a backup of the EEPROM if you have a reader. Finally, you say that dont't fix it if it ain't broken I would recommend at least have a look on the switch solder joints as arcing can cause big problems if it is not fixed.
This is not exactly related to this video, but why don’t you team up with Swiss Micros to make a proper calculator for electronics, a bit like the fx61, but available to buy. Good engineering functionality, unit conversion and useful things like this? I would get one! And I bet a lot of people would also 😊
@@max_kl You are right, and I have one, it is a great calculator that costs next to nothing. But I keep leaving it next to the HP11c in the hope a miracle happens ;) I want RPN and the “feel” of the HP, but with the functionality of the Casio.
I sense a repair vid coming up. First guesses, maybe power supply related, or perhaps in the circuitry driving the display as that might have a higher voltage. A bad cap? Dry sauder joint?
I would guess it's heat cycling, some component is sitting right on the point of failure and any variance in the temp tips it over, it then cools off and restarts. That could explain the no fault with the case open. Slightly better cooling for that component.
If anyone has this issue, the solution is to clean power supply output pins.. In older models there is no gold plating so oxides have grown causing intermittent power failure.
2 года назад
I have a 2400 device, it said "No Comm Link" error, I checked according to Keithley's repair guide, U15 & U16 are smd types and solder joints are good. What should I do next to fix it. Thanks for supporting me!
Hi, Dave, you have all this gear that you rely on being accurate. Do you have a bit of gear that has its annual NATA cal check to make sure your lab measurements are accurate. At my workplace we have a Keysight model 34470A DMM, it gets NATA certified each 12 months, we do DMM certifications for various organization and trades and use this as the sighted NATA device. The Keysight is also used for published test results on refurbished or manufactured equipment we work on. There are a number of work places which now need to have annual equipment certifications, manly to conform to Australian design or workplace requirements. I would think a lab like yours would have to as well have one NATA certified device to check your other bits of gear. The Keithley looks like an over heat problem, but doing a cap change after all these years is also a good exercise. It will be interesting to see what you find. Note that the display blanks out, rather than fades or displays junk before it does its reset.
The Signal Path just did a video on a series 2000 repair that are plagued by bad caps from the 90's and potentially can destroy the meter if left too long. perhaps yours is also plagued ruclips.net/video/eLGWGXfDqxg/видео.html
![I.N "HALLUCINATION" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/n5B5q1Hwt_U/mqdefault.jpg)
NOTE: This was going to be part of a repair video, and it's been available to supporters for many days now. But it's only failed once since I took the cover off to investigate and hasn't failed since.
If it ain't broke I can't fix it, so here is the video anyway.
Ha. This kind of bugs is the worst. Those pesky little buggers bug you, but when you get round to pinning them down, they run like cockroaches after turning the light on.
I once had a Tascam DJ mixer in for repair in a field setting and didn't even have a multimeter on me, let alone a scope. A few pros . Basically, a soldermask was damaged under one of the slider pots, and a power trace had an intermittent short to GND, resulting in the mixer going haywire.
That could actually point to a thermally related (intermittent) failure. Have you had a look with the thermal camera? Maybe some component just gets too hot with the cover on or some electrolytic is going bad.
It waits till you leave the lab ;-)
I once tried to repair a stereo amplifier where one channel would randomly start outputting max volume for a few seconds. It did that all the time, like every few minutes in normal operation. But it would never do that when I had the cover off, so I couldn't debug it. So frustrating! I was never able to fix it.
Intermittent faults are the worst. In my day we used freeze spray and cheap ass hairdryers (no cheap hot air stations then) to trigger and confirm faults with semiconductors quite quickly. This is obviously after percussive diagnostics failed to trigger the fault condition.
Mmmm test equipment repair, right up my street..........looking forward to the repair video.
I just treated the same ailment a few days ago, it was disappointingly easy in my case. Care for a spoiler?
Considering that it's now been running for 2 days straight with the lid off and has only failed once now that I have seen, I don't like my chances of being able to diagnose it any time soon, so yeah!
@@EEVblog2 For me it was an empty memory battery on the digital board. U2, a Dallas (typical!) DS1236 with one of its key features being "Halts and restarts an out-of-control microprocessor" doesn't seem to like empty batteries
@@reps Thanks, will check it out. My first check would have been the PSU, and then monitoring the rails and triggering off the CPU reset line which would capture this if that was the case. Actually, the battery would have been part of the rail checks. Haven't done anything yet, just waiting for the damn thing to die again.
@@reps Well scratch that, I measured 3.08V on the lithium battery, both on and off. Still no more fails.
@@EEVblog2 30min off and the battery has creeped up slightly into the 3.09's, exactly as you'd expect of a good celll.
ohhhh... looking foward to the fault investigation!
Dave you know what that means... *REPAIR VIDEO!*
Random resets, just like my old Fluke/Phillips Scope. These are the most frustrating things to find and fix! Good luck. :-)
We have a large number of 2400s at work and they are starting to succumb to age with PSU faults like this. Had a few that randomly blow the fuse on the mains plug (UK so fused plug)
Send it to me and I will fix it... I might even send it back LOL.
Perhaps a cold solder joint, flaky connector, or flaky cap? Some of these 2400s can get up there in age, think they were first released in 1992! If you plan on keeping it, recapping the PSU/digital stuff and a little contact cleaner/deoxit on the interconnects couldn't hurt either. Plus the internal system battery and the fan could always use a refresher after many years and hours.
Need a Ghostbusters. In late 70's, the game manufacturer said replace the DACs. If that does not fix the problem, put the board on the floor and drive a forklift over it and replace everything that breaks!
Have you tried turning it off and on again... Ha ha ha.. 😜
It's a reboot. So I'm going with a cap, power supply. And my favorite, EMI issue from a switching power supply maybe from what it's on top of.
I had the exact the same thing. Most likely the mechanical power switch which gets some serious mechanical torque from the front switch which is just a long white plastic rod which goes all the way back. This torque breaks the solder joint of the switch. I just soldered the power leads directly to the PCB bypassing the switch. Add an external switch to the cable or use the cable as switch and you are set. It was a relatively easy fix.
While you are in the unit, change the battery as well since it can give symptoms which are similar. Also, make a backup of the EEPROM if you have a reader.
Finally, you say that dont't fix it if it ain't broken I would recommend at least have a look on the switch solder joints as arcing can cause big problems if it is not fixed.
This is not exactly related to this video, but why don’t you team up with Swiss Micros to make a proper calculator for electronics, a bit like the fx61, but available to buy. Good engineering functionality, unit conversion and useful things like this? I would get one! And I bet a lot of people would also 😊
Check out the casio fx-991x, it's served me well so far
@@max_kl You are right, and I have one, it is a great calculator that costs next to nothing. But I keep leaving it next to the HP11c in the hope a miracle happens ;) I want RPN and the “feel” of the HP, but with the functionality of the Casio.
It's time to resolder ROHS joints. And may be replace caps, as said earlier.
It's already hooped, can't make it any worse.
Dave: Hold my beer...
Ooooh repair video incoming! Do it! 😆
Must be a cold joint or bad cap! LOL
Definitely waiting for a teaardown/repair video. Test equipment porn turns me on.
i have seen this before with a simmiar unit i had after much dicking around i found the battery was dead.
I sense a repair vid coming up. First guesses, maybe power supply related, or perhaps in the circuitry driving the display as that might have a higher voltage. A bad cap? Dry sauder joint?
I would guess it's heat cycling, some component is sitting right on the point of failure and any variance in the temp tips it over, it then cools off and restarts. That could explain the no fault with the case open. Slightly better cooling for that component.
Time to replace caps on PSU/digital board.
Hi Dave....It looks like a false contact inside.
Yeahhhhh,. (Oeps sorry) one Murphy repair video serie coming up!
If anyone has this issue, the solution is to clean power supply output pins.. In older models there is no gold plating so oxides have grown causing intermittent power failure.
I have a 2400 device, it said "No Comm Link" error, I checked according to Keithley's repair guide, U15 & U16 are smd types and solder joints are good. What should I do next to fix it. Thanks for supporting me!
Hi, Dave, you have all this gear that you rely on being accurate.
Do you have a bit of gear that has its annual NATA cal check to make sure your lab measurements are accurate.
At my workplace we have a Keysight model 34470A DMM, it gets NATA certified each 12 months, we do DMM certifications for various organization and trades and use this as the sighted NATA device.
The Keysight is also used for published test results on refurbished or manufactured equipment we work on.
There are a number of work places which now need to have annual equipment certifications, manly to conform to Australian design or workplace requirements.
I would think a lab like yours would have to as well have one NATA certified device to check your other bits of gear.
The Keithley looks like an over heat problem, but doing a cap change after all these years is also a good exercise.
It will be interesting to see what you find.
Note that the display blanks out, rather than fades or displays junk before it does its reset.
How's the cooling fan?
Aren't those old keithley ones "famous" for their leaking caps?
Start from ESR-testing electrolytes
The actions were correlated, just not causal...
You may want to just change the power cable with another one to totally discount it. Looks like the PC type.
Did you update the firmware? Also I guess this isn't the issue.
"Keithly seems to have done himself a mischief."
...fixed the fluke.. lost the keithley
Oh mate, this is going to cost. Back to the Cadogan statement: "Shitsville" is going to cost more...
Don't turn it on, take it apart.
And don't use the automatic range switching if you are performing delicate measurements. Some Keithlys make funny stuff if you do measurements at 0V.
More related to the sourcemeters.
@@berndrosgen1713 The 2400 is a source meter.
@@ferrumignis Yes, that is which I used most.
good vibes
Your POR fluid is low. Needs a refill.
Oh Naur Its ComeAGutsa. Better have a squiz. Wiggle Wiggle Wiggle Yeah. Shell Be Right M8.
Он устал.
Even has a great VFD, not that LCD rubbish.
How did Marco Reps reply 4 days ago when the video was posted today? (19th feb)?
patreon?
Time travel?
Seriously? Doesn't anyone read the description or the pinned comment?
@@EEVblog2 Very few people that comment ever seem to read the video description.
@@EEVblog2 Mate those electrons take a while to make it up to blighty from your end…😝
The Signal Path just did a video on a series 2000 repair that are plagued by bad caps from the 90's and potentially can destroy the meter if left too long. perhaps yours is also plagued ruclips.net/video/eLGWGXfDqxg/видео.html
Video fixing it !! Please!! PSU hiccup most likely
You wasted my time - sorry.