Test Equipment Anonymous (TEA) group therapy thread

[bd139]

Its normally built into the IEC connector and has a built in fuse?

The EMI filter is built into the IEC connector but the fuse is separate.

It's the EMI filter built into the IEC connector. They do a lot of damage when they go.

[Cerebus]

I scrolled for several minutes, but my favorite is right at the top; that kangaroo with a dog in a headlock.  That's the sort of story you tell your grandkids and they think you've lost your marbles. 

I just love the look on the roo's face after the bloke clocks him one. All kind of "What? That's not supposed to happen! I, I, I,... [speechless]".

[BravoV]

Does that have one of those schaffner filters in it? I'd swap that out if you can if it does. That'll be the next thing that blows up and they go off in style.

I'm not familiar with a schaffner filter. Here's the primary side of the Inverter circuit. Does it have one?

Yes, it does, better check the brand printed on it.

Its the grey metallic box under the yellowed white tube on the left side.



Also the plastic caps, as above photo those red boxes, if yours are transparent ones like below examples, replace them asap. Other wise they will pop too like these ...

[mnementh]

Yes, its a jack of all trades but master of none as the saying goes, if they could fix the slight bugs and quirks it might be a really great purchase. I know Dave used to seriously recommend that model as a "no brainer" go get one but was 3 years ago.

All scopes are a jack of all trades though. They're mostly useless in the frequency domain, the time domain isn't all that accurate either and the voltage measurements aren't that good really. This is why we have DMMs, frequency counters etc as well.

However it's the only tool that does all of the above at the same time and draws them on a pretty picture and in this case allows it to hang around longer than the phosphor would

The bugs that remain for me in the Rigol are the shitty FFT implementation, some UI lag, naff probe coax and the DC drift that plagued my last unit resulting in a self cal needing to be done every week.

The big non bug is the price, crackability and the fact it has an ethernet hole in its bum.

Tradeoff really which it still wins pretty well. Keysight's offering I was looking at was about £1300. Versus £370 it's a no brainer. Siglent is pretty good there too (nod to tautech) but the distributors in UK are shit so you have to buy it from EU which has a worse statuatory warranty on it than if you buy it here in the UK

Which is precisely why I'm not ashamed to have one on the bench right under my 2465.  I do a lot of work with SPI and I2C bus in my quadcopter hobby; this little beast was born for that kind of dirty work.  The hackability was a selling point for me; the noisy power supply issues were something I thought I might address sometime to resolve the associated quirks, but as others have mentioned, the quirks of the UI are much more obtrusive in general. Once you get used to navigating it, the thing carries quite a lot of functionality for the price.

I spent quite some time carrying on a fun ethics argument over the whole Rigol hack thing in another thread; but eventually it turned into a telenovela with folks arguing the most idiotic semantic nits recursively for days. 


mnem
Toasty-errr...

[mnementh]

My turn for a crap out. The recently purchased 2465. Complete power loss. Shit! Check the fuse and it's OK. So I tear it apart. I have AC power in. The EMI filter is OK. No blown caps. But no mains AC to the primary rectifier bridge at the input of the DC bulk for the switcher. That's strange. Finally found the culprit. The power switch itself. It's a DPST switch and one side was open. So as a temporary measure I jumpered that side of the switch and the scope powered up. For now it's fixed. But I really doubt I'm going to find the proper replacement switch unless I rob it off a carcass. So I'm thinking about a more permanent solution.

While I had the Regulator and Inverter boards out I looked them over real good. They both have original factory caps. No bulging or leakers that I could see. But I'm now definitely going to order replacements and get it done soon. And figure out what to do with the power switch.

That is one thing I'm afraid I can't help you with. My one spare is already in service.

Oh, lookie here... it appears a suitable replacement is still available; a fellow found one and posted about it here on eevblog. You may wanna try and find that switch on DigiKey since Mouser shows them still "On Order".

Also... I stumbled across this recap kit while looking for that switch; it seems a bit expensive, unless you count your time tracking all the parts down as worth more than minimum wage.


Cheers,


mnem
Rejoice, Rejoice, all ye on the low-carb diet!
For on this day has been delivered unto you the BACON TOASTER!!!

[mnementh]

I scrolled for several minutes, but my favorite is right at the top; that kangaroo with a dog in a headlock.  That's the sort of story you tell your grandkids and they think you've lost your marbles. 

I just love the look on the roo's face after the bloke clocks him one. All kind of "What? That's not supposed to happen! I, I, I,... [speechless]".

Yeah, he looked just like my math teacher Mr Wilkes when I told him why I lied about losing my math book. 


mnem
What you didn't get to see was the part where the roo chased the guy down and launched him with both feet... 

[beanflying]

3rd Scotch while cleaning up the shed = 5340A with Nixies 

I am blaming the cleaning as I found a 2U space free 

Must find the photo of my Mum in Bed in a Caravan when Mum Roo and Joey came in to say Hi 

[med6753]

Does that have one of those schaffner filters in it? I'd swap that out if you can if it does. That'll be the next thing that blows up and they go off in style.

I'm not familiar with a schaffner filter. Here's the primary side of the Inverter circuit. Does it have one?

Yes, it does, better check the brand printed on it.

Its the grey metallic box under the yellowed white tube on the left side.

I really didn't pay much attention to it but unless I'm having a brain fart I think it said Toshiba on it. I would have to go back and verify that.

Also the plastic caps, as above photo those red boxes, if yours are transparent ones like below examples, replace them asap. Other wise they will pop too like these ...

I am well aware of those caps and their reputation for explosive failure. This 2465 has one, the other is a different type. I looked it over and the cracking normally seen on these caps is almost nil on this one. But I certainly agree it has to come out. I have a chart (attached) that originally came from the old Tek Yahoo Group outlining all the caps on the Inverter and Regulator boards. I used that chart to re-cap a 2465 DMS several years ago and it proved very valuable. I will use it to re-cap this 2465. I am also aware that the service manual has errors which can lead to incorrect placement of caps resulting in magic smoke.  I avoid that issue by doing one cap at a time...matching value, voltage, and polarity. It takes longer but it results in an accurate rebuild. The 2465 DMS powered up fine first try after it's rebuild.

[med6753]

That is one thing I'm afraid I can't help you with. My one spare is already in service.

Oh, lookie here... it appears a suitable replacement is still available; a fellow found one and posted about it here on eevblog. You may wanna try and find that switch on DigiKey since Mouser shows them still "On Order".

Thanks for the lead. It turns out DigiKey has it in stock. I'm going to put in an order. 

Also... I stumbled across this recap kit while looking for that switch; it seems a bit expensive, unless you count your time tracking all the parts down as worth more than minimum wage.


Cheers,


mnem
Rejoice, Rejoice, all ye on the low-carb diet!
For on this day has been delivered unto you the BACON TOASTER!!!

That rebuild kit looks interesting but I think his price is a little high.

[bd139]

Just a point on the EMI filters on these. The little silver box actually contains 2/3 RIFA X2 capacitors and a common mode choke usually. RIFAs are pretty bad on their own but when you put them inside a pipe bomb, interesting things happen. We had one much newer than that in a SAN power supply and it blew its load all over the inside of the unit. I have a photo somewhere in the office I will dig out but it was a right mess.

[BravoV]

I have a photo somewhere in the office I will dig out but it was a right mess.

Please do, it will be a good reference for motivational photo. 

[Specmaster]

Heres a video that shows one, but not blown, instead it shows the choke and the Rifa filters.

[bd139]

That one looks like a much newer type. The older ones have an X2 across the line, a resistor across that to heat it up nicely (and stop you zapping yourself when it's unplugged) and a couple of Y2's which tend not to explode.

While I am not in the office, here's an EEVblog reference ... HP 3457A explosion: https://www.eevblog.com/forum/testgear/just-got-3457a-and-then-boom/msg479303/#msg479303

[ElektroQuark]

Are all those filters dangerous? Or is there a data from when their are confiable?
Alternatives to them?
Can they be opened and ofending capacitors changed?
Do those filters deserve a full thread?

[med6753]

That one looks like a much newer type. The older ones have an X2 across the line, a resistor across that to heat it up nicely (and stop you zapping yourself when it's unplugged) and a couple of Y2's which tend not to explode.

While I am not in the office, here's an EEVblog reference ... HP 3457A explosion: https://www.eevblog.com/forum/testgear/just-got-3457a-and-then-boom/msg479303/#msg479303

I am confident that the EMI filter in the 2465 is not made by Schaffner.

[bd139]

Doesn't mean it's not going to blow up

I had another vendor's one blow up in a Philips scope. Hissed like an angry snake. Fortunately it was burning in with the case open on the table so I got to shut the power down before it went.

They are replace on sight "if older than 20 years" disposable parts really. We're way beyond the design life.

Might be worth checking temperature of it after an hour or so. That's a good indicator. They don't run hot unless there's something wrong with them.

[Specmaster]

While playing around with my S63A signal generator yesterday my 1740A scope decided to keep your 465 company  What happened, the LED for the "UNCAL" indicator on the sweep vernier failed and I thought "bastard" thinking I'd have to strip away the timebase switch cards and go through the painstaking re-alignment of the switch shafts etc.

Thankfully, just removing the 8 switch push rods (black plastic bits bent at right angles in 2nd photo) above it meant that by using a pair of long nose pliers I was able to effectively replace it. It was a bit of a squeeze with my big hands but its working OK thanks to the quirky way those push rods snap onto the switches it was relatively easy.   I do like HP gear, its generally well designed and thought out in its construction.

[bd139]

Yeah that construction is much better than Tek, which usually starts with "so how the hell do I get at that without having to remove the interface board" and head scratching for half an hour.

Have to be very careful with the latching changeover switches however as they get very brittle with age. I actually broke the end off the mains switch one in the 3478A when I was cleaning it and replacing the filter caps. Just literally nudged it slightly and it fell to bits. Drilled a hole through the middle of both halves with the Dremel and added a metal pin and some epoxy. Has been fine since 

[tautech]

I am confident that the EMI filter in the 2465 is not made by Schaffner.

Seems so as the mains filtering is on another PCB.
Shown here:
https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/msg425034/#msg425034

[med6753]

Doesn't mean it's not going to blow up

I had another vendor's one blow up in a Philips scope. Hissed like an angry snake. Fortunately it was burning in with the case open on the table so I got to shut the power down before it went.

They are replace on sight "if older than 20 years" disposable parts really. We're way beyond the design life.

Might be worth checking temperature of it after an hour or so. That's a good indicator. They don't run hot unless there's something wrong with them.

Agreed. I will check it next time I open up the scope. Which will be soon because I ordered a new power switch.

But it does appear that these units fail a LOT more often at 220V rather than 120V. 

[Specmaster]

Yeah that construction is much better than Tek, which usually starts with "so how the hell do I get at that without having to remove the interface board" and head scratching for half an hour.

Have to be very careful with the latching changeover switches however as they get very brittle with age. I actually broke the end off the mains switch one in the 3478A when I was cleaning it and replacing the filter caps. Just literally nudged it slightly and it fell to bits. Drilled a hole through the middle of both halves with the Dremel and added a metal pin and some epoxy. Has been fine since 

I'm dead chuffed with the 3478A, we did well with those at the time 

[bd139]

Yep that and the TF930 are this year's star buys so far

[Specmaster]

I'm sure there will be others soon 

[med6753]

When we were discussing scope calibrators last week I wanted to include some sample wave forms   but I didn't get a chance. So here's some now. It's the “Time” output of the Heath IG-4244. Scope is a Tek 2465 DMS with 300MHz bandwidth. Channel 1 50 ohm input. Per the Heath manual ringing of the wave form on the trailing edge is normal. But there should not be ringing on the leading edge.

Pix 1 – 10MHz

Pix 2 – 20MHz

Pix 3 – 50MHz

Pix 4 – 100MHz

As you can see via the frequency readout display it's pretty much spot on. It does drift a little as it warms up but that's to be expected. 

[BravoV]

2.5GHz thingie, not my fault, blame Berni.