วีดีโอ

Thanks as always for the analysis Andy! Yes I am not a fan of the membrane switches. Especially when they are used in areas where this enough space for snap-action switching and PCBs (as is the case here). In my experience, as long as you balance the rotor properly, these things can be pretty tame. I wouldn't put any sensitive equipment on the same bench (which has been done in the past causing sensitive optics to go out of alignment which I then would have to fix 😂). Interestingly, for the type of rotor we use, the imbalance sensor won't go off unless the rotor is offset by ~50g! That is a lot - you should see one of these with that kind of imbalance. Believe it or not, that is actually what I do to test the imbalance sensor! 😂. But to your point, I've never had any connection issues with that SMD ribbon cable connector and we have about a dozen of these fuges. Merry xmas to you and your family as well!

@@fmashockie :)

Thanks alot Duncan for your continued support and thoughtful comments - it is much appreciated. It is very expensive to service lab equipment; especially by the OEMs. I try to share this experience in the hopes other scientists will find it so they can keep their labs running for reasonable cost. Merry Xmas to you as well!

thank you!

thanks for the explanation Andy! Yea all I know about them is that they are semiconductor devices and that you apply voltage one way it 'heats' and if you reverse the polarity it 'cools'. So I appreciate the in-depth points there. That is one of the reasons I made this channel - to learn from others in the comments with more experience. That happens more often than not!

@@fmashockie :)

Thanks Andy! Its been super busy at work so I haven't had much time to devote to videos, but hopefully things will slow down a bit after the new year! Hope you are well!

@@fmashockie :)

as Dave at the EEVblog likes to say - "please excuse the absurdity of the model; didn't have time to build it to scale" lol!

thanks Duncan! Plenty of resources online how to repair microwaves and it tends to be the magnetron that fails. But personally, I'd never digged into one and had a lot of fun with it! Also I only started using LTSpice recently and it is awesome! Free to download and fairly easy to learn how to use. Thanks for always watching!

I don't have a whats app but you can reach out to me via email fmashockie@gmail.com

thank you Duncan! I just subscribed to your channel!

thanks for watching! Its a very easy mod to do if you already have the tools! This one is still working great!

​@@fmashockieI would love to have your email address or WhatsApp number for future consultations, kindly

​@@fmashockiehey Frankie I have another similar miniamp plus with the same issue but has failed to clear error on display

@@emmanuelnthanga938 Hey emmanuel I'm not quite sure I understand your issue. This video covered failing temp verification test results. By installing an offset shift resistor, you can bring the temp sensors back into spec. But you need to play around with the value to get it right. This particular instrument had no errors, just failing temp verification results for accuracy. An error on the display tends to mean a hardware issue. Also, if you tried following my video, and you installed a resistor, and then you got an error, that means you have picked the wrong resistor value. A value that brings the resistance to low will assume the sensor has a short, a value that brings it too high will assume the sensor has an open fault condition.

​@@fmashockiethanks alot I managed to clear the error but after doing this modification with 4.7Mohm resistor the temparatures are still raising to 109°c thus bringing back the error to the display, what other resistor can you advice kindly

hey! So I am not familar with the TC100 turbo pump controller at all. I assume it is an electronic driver for a pump? Anyways, I can only speak to your issue in very general terms. Just because it has a XC164CS doesn't mean I can tell you much about your issue. Microcontrollers are designed to be versatile; how they work depends heavily on how they are programmed. What do you mean by press it? Do you mean when you press on the XC164CS? If that is what you mean, then there could be a few things going on here. It could be that you have some cold solder joints on the pins to the chip. You can do a visible inspection of the pins using a 10x or greater microscope (even a magnify glass would suffice) and check to ensure the pins are soldered properly. You can reflow the solder to be safe. You can also check each pin for continuity with a multimeter but you have to be careful there because even pressing on the pin with a test lead could cause it to make contact with the pad giving a false reading. Alternatively, pressing on the micocontroller and causing it to work could have nothing to do with the micro at all. It could be that you are just flexing the entire PCB and that is causing some other faulty connection somewhere on the board to work. So you want to do a visual inspection of the entire board. If it turns out the issue is related to something internal to the microcontroller, you can follow this video to see if you can still interface with micro via UART to USB using the Infineon software. If you can, you should be able to flash the existing micro (if it is not read protected) and then replace it with a new one and reprogram. Good luck!

Thanks for going easy on me! But now you might judge me... still haven't done anything to it yet. the piece is still sandwiched in there. It's been perfectly fine

Issue was resolved by the end of the video. It was one of the TTL counters that had gone bad

I bet! Even this 450 has some kick!

Hey thanks for watching and commenting! Thank you for your service as well! I think the easiest thing you could do is grab yourself some DeoxIt. Pull the knobs off, take the top panel off. And with the unit off, spray the knobs with DeoxIt. You want to try to penetrate the knobs and switches any way you can. Most pots have openings on the backside where you can see the wiper. So you can spray inside there. You can also spray the shaft - some cleaner will make it down the shaft into the internals. The trick is to exercise the pots a lot after and during spraying. Turn them back and forth dozens of times. Same with those switches. Those snap action switches get dirty all the time. But the usually have some kind of opening in the back that you can hit with cleaner. Exercise them a lot, too. Give that a try first. Fortunately, the service manual is still available on line for that amp/receiver. So you have a resource there as well. I am definitely no expert on these. This was the first one I tried to repair. Was a lot of fun though. That Kenwood also looks like a very pretty amp!

Make sure you allow plenty of time for the DeoxIt to dry after spraying because all that excess spray will get on the circuit boards. Do your best to clean it up and let it sit for 24 hrs. It should all dry up by then. And then you can power it on to test it!

Thanks Charles! Yea this was a lot of fun! I wouldn't mind working on more of these. Wouldn't mind having one of my own for the lab either 😁

Thanks for watching! So you're going to want to take a look at how many cycles you are running a quarterly basis. Consolidated bases their recommended servicing on 300 cycles per quarter. We barely do half that. So I tend to double the frequency time they recommend (for ex. they state rebuilding valves every 6 months, I do it every 1.5yrs and that works just fine). You should have been given a service manual with your unit that provides all the recommended change intervals. Make your PM program based on that, and adjust based on usuage. Also, your water quality will play a huge role in the part change frequency as well. I would highly encourage you to test your water quality. Because if you don't it could void the warranty on the chamber/jacket vessel. If your water quality is below manufacturer recommendations, get an RO system on it. Yes it will be money upfront, but will definitely save you in the long run. Prioritize the boiler (if your unit has one). Keeping it clean will prevent you from changing expensive heating elements (this one still has the originals after 5 years), water level probes, baffles, etc. Next would be valve rebuild kits and steam trap kits. And then you have items that get changed less frequency like check valves, safety relief valves, pressure regulator, pressure switches, etc. In short, you'll need to customize your PM program based on your usage and water quality. But it is very easy to do! Just be safe!

I should mention that since there are half a dozen or so valves on this unit, rebuilding them every 1.5 years, I stagger them so I'm always rebuilding at least one of them every 6 months. Rebuilding all of them at once, in addition to all the other work that must be done, would be quite a lot!

@@fmashockie Thanks for the heads up. That's what we usually do with our PMs is build out a few at a time. How often does it need a gasket? Any other parts you change out every PM or every year?

@@nickgaffey everything you see in this video is how I treat a PM. It will all depend on your usage as I said before. Check the HMI controller to see how many cycles you run quarterly. Check it once and then check again in 3 months to see how many cycles you ran. Base your part replacement frequency on that. Other than valves, traps, check valves, there's not much I change preemptively. Most everything else is as needed. You can replace the gasket preemptively or wait until it starts leaking steam 😂. That's one of the parts I like to have on hand just in case, but generally we see them last ~2 yrs.

The battle station right now = setting up on the floor 😂. It's tough when you're sharing a 1 bedroom apt with your gf in the city!

@@zairulyusoh thank you! I don't know how much knowledge is in there, but it is definitely an experience 😂😂

yes it is 50 ohm terminated. The TDS 754 has the option to change the input from 1meg to 50ohm. I really enjoy the simplicity of the 8654. Thanks for watching and commenting!

@@macboi7601 it's an effect from the camera but looks pretty cool right? 😂😂

The framerate is fast enough that it's seeing the trick Tek pulled to get colour displays on these scopes. It rapidly switches between red, green and blue, changing which part of the LCD is active for each colour. The human eye blends it all together (though if you dart your eyes back and forth across the display you'll see brief flashes of colour).

@@AureliusR thanks for the explanation!

@@susanrobins4297 thanks!

😂😂 I see what you mean! thanks!

@@dz-abouttechnique1849 thanks!

@@TheGmr140 thank you! I was really impressed with how they designed the range switch. I shouldn't expect less from HP tho!

@@YuMiao-sc7vn no there is no service manual available for these. At least to customers. I traced the circuit out myself and came up with this on my own

thanks Joel! Always appreciate you taking the time to watch and comment!

Thank you!! I just left a comment on your video 😂 Really appreciate you taking the time to watch and comment. The reason I assumed the mechanical relay is for in-rush current from AC input is the fact that it switches on immediately; as soon as you apply mains, but before you flip the mains switch on. This is before the PFC circuit is engaged. But you could be right!! And yes I am beginning to think the fan control is related to lack of reaction module. Would have loved to had one on hand so I really could have put this thru a serious load test!

And yea the Valhalla 2101 is a great analyzer! Just watch out for those gang switches. When they get dirty, they start causing all kinds of strange fault symptoms!

Am repairing one the now (same pcb different part number) so you two's videos have been most helpful. The unit i have sometimes starts but always starts tripping on and off after a while. Am hoping it's the capacitors on the quiescent supply. I stripped them out and found 1 with very high ESR.

@@hopper7755 could be! I'd love to troubleshoot it further but without the reaction module, it would be difficult to get additional clues on the state of the HC12 micro.

i was wondering the same

@@yanfishtwig2356 there isn't much overvoltage protection at the AC input. No MOVs. unless they are in the external EMI filtering module but usually that isn't the case

Thank you sir! Well the same goes for me.. as you can see from exhibit A above! 😂 The main reason I shared it is because I didn't really see many vids for this repair on this make/model/year. And working on cars really scratches that repair itch when I can't be in the electronics lab. I really enjoy it!

Thanks Joel! Ive never done any welding before. So I'd have to look into that. Also, the ignition coils were probably the first repair I did on this vehicle when I was very green to car repair... So I don't think I did...

thank you sir!

thanks Andy! And good point 😁

thanks! yea I still have a lot to learn about RF transmission and matching impedence. Appreciate your input and thank you for watching the vid!

I should mention that the TDS754 has 50ohm input which I had set. I was thinking this roll off was due moreso to the lack of bandwidth when measuring 250MHz on a 500MHz scope. Would I still need to terminate with 50ohm termination?

@@fmashockie Yes Frank it should be OK with a 50 ohm termination. Some scopes have this. You could check your generator attenuator against the hp attenuator you have.

​@fmashockie I don't think any quality scope will be showing that much rolloff at only 50% of the bandwidth. Most good, brand name scopes I've used are very flat until you hit about 90-95% of the bandwidth.

​@@AureliusRPlease review this article. It is all derived from the equation for bandwidth which = 0.35/rise time. If you want accurate measurements for signal amplitude at 100Mhz, you're going to want a 300MHz bandwidth scope, for example. I don't know what tricks they have come up with on newer scopes, but this technical bulletin is from 2009, and the TDS 754 is much older than that. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/people.ece.ubc.ca/robertor/Links_files/Files/TEK-Understanding-Scope-BW-tr-Fidelity.pdf

Glad you found it helpful! Link for downloading MemTool is in the description

Yep thats correct!

Do you offer service on these? Can I ship you only the board for replacing the shuts? I'm in San Diego so shipping the whole centrifuge is not ideal. Thanks.

@@anytimelabtrader Yes! I just started taking on independent work. For lab equipment PCBs and power supplies. I can offer competitive pricing, quick turnaround times, and a warranty on repair. If it is equipment I already have here (like the XTR for example) no need to ship the entire unit. Other equipment that I don't have available, but you'd like a board sent would have to be evaluated on case by case basis as to whether the board or the entire unit is required to be shipped. Feel free to reach out via my email at fmashockie@gmail.com. But if you do wish to try to replace the shunts yourself, here's the link to the ones I use www.digikey.com/en/products/detail/sumida-america-inc/CPFC74NP-PS02H2A20/1879019

Thanks Andy!

Thanks Duncan! Really appreciate your input and feedback!

Yea that power supply was for a bigger beast! Ultracentrifuge that goes up to 90k rpm! This guy only does I think a max of 15000rpm (depending on rotor type). And yes the blue things are current transducers using hall effect technology! LTSR15-NP. I know one is involved in the protection circuit.

thanks for the feedback Joel! 🙏🙏

Thank you!!!

Hey glad to help you out but which part are you referring to exactly?

Hi Frankie,it,s the attenuation/ref level/variable and the bandwidth /resolution they seem to have concentric shafts all very complex. Also yours has a mechanical freq readout mine have electronic display (dont think its a counter just a DVM display). Thanks

@@mechmania8450 gotcha. Is yours a 8557A? I know some of the 8557s had digital readouts. So you need knobs for the Optimum Level, Coarse Reference Level, and Fine Reference Level. As well as knobs for the Frequency Span/Div + Bandwidth Res? Thats 5 separate knobs. Am I understanding you correctly? If not why don't you shoot me an email (will need a way to send you photos anyway). My email is in the bio of my channel

You might get some additional help by looking at the service manual. It has an exploded diagram of the front-end. Because yes both those switches are concentric. But one is tri-stacked (amplitude) and the other double-stacked. You correct it is a pretty complex set of switches.

@@fmashockie Hi Frankie Cannot find you email. I have a scale for the attenuation/ref level and I am making a knob in aluminum. However I am not share how the bandwith/sweep width works there is a hole on the panel. Had me confused for a bit with the atten knob which has a channel front to back however this is not needed but it must weaken the knob. But I still wonder how the bw/sweep works. I have repaired helipots in the past ,bad connection at end of wire wound track.. Use some agressive soldering flux.

yes! been meaning to get one of those for a while!!!

@@fmashockie :)

For switching power supplies, rule 2 might be check your frequencies (only makes sense if you have a known good unit). Aside from microscope inspection that someone else mentions, a thermal camera would often be helpful.