วีดีโอ

yes they can sell you the regulator as well at a reasonable price. Your test does seem to indicate the same failure mode as mine, e.g. dead cpu due to shorted reg

the challenge to replace the USB conn is mainly access : as you see it's tucked under the plastic rear panel, which is a bit of a pain to remove (unless you don't care about esthetics once reassembled). Or leave it in place, but then the desoldering operation is quite tricky. Maybe with a dremel and a deft hand it might be possible to cut up the old connector and remove it piece by piece ? Could be difficult to do without damaging neighboring parts. And the middle part with the fine pitch contacts is delicate. You know your skill level, if you have not done much fine-pitch stuff there is a real risk of ripping traces, which takes the repair to a whole other level.

nice ! good to know, will have to check.

online, you mean music ? goodness no, that stuff stays offline haha

@@fenugrec5697 lol I played guitar and piano a bunch in high school, then base in church growing up. I miss it, but for some reason know that I’m married and “emotionally right”….hard? lol who knows. I just can’t get into it. It was a huge passion. I could express my soul through guitar and piano. It was a steady hi. So not having that now is alien to play. When my kids get older I’ll teach them and we will jamb.

Hi, I recommend you post to the groups.io HP-A-K mailing list, groups.io/g/HP-Agilent-Keysight-equipment . It is a much better place than YT comments for in depth technical discussions.

@@fenugrec5697 Thank you for your reply. I have tried to subscribe to the group and it does not allow me to participate. I can only see the messages. I have a notification that my email is not valid and it is the one I always have. Can you tell me what the problem is or what I should do?

Thanks for the offer, will keep in mind.

@@fenugrec5697 Anytime! If possible, would love to keep in touch! May i know your email?

> Are you a musician ? Haha I pretend, when nobody's looking !

Try a few different cable(s) , computer / hub / port combinations.

@@fenugrec5697 tried everything. unfortunately, no luck. Is there a way you could show me what to measure exactly to identify the exact problem? I have a multimeter and would be more that happy to learn about this topic :). Went to your page but no further explanation on the subject :(. Hope you can help me.

Hi, unfortunately what I have on my website is about the maximum amount of detail I had energy to explain. I reasoned that replacing the CPU is a challenging task that would realistically only be undertaken by somebody with the knowledge to probe around and troubleshoot; as I may have stated in the video definitely not an easy repair, although the troubleshoot itself is not terrribly complex. More that can fit in a comment reply, anyhow. If you still want to pursue this, go to that page on my website, look up the datasheet for the problematic components, and try to figure out which voltages are where. Probing voltages (carefully) in a defective 4i4 is essentially harmless at this point

Try downloading the drivers for the interface

@@Middas no luck :(

Do you have a website or forum where I can ask about the topic? Thanks.

I don't fully understand your question, but if you are dealing with a motorola / freescale mcu, you would need different software : HEW is strictly for hitachi/renesas processors. But I assume similar methods should be available. Forums are getting out of fashion it seems; Romraider has a "misc ECU" subforum but it's usually quiet

@@fenugrec5697 I mean I'm using IDA pro and GHIDRA to try to disassemble the binary. I have not been able to find a reference to the maps or DTCs that I have in winols. I have not found an example with Motorola MC68332 to apply to my research.

U31 and U27 definitely as a minimum; 1V reg should not be impacted but worth checking before installing the new U27 obviously. Clock gen and SPI flash , to my knowledge, are the only other things that could in theory suffer from a shorted 3v3 rail but are usually OK ?. I understand MP1605 and MP2141 is essentially the same silicon, maybe some packaging differences. I'd be really curious to talk to focusrite and MPS engineers to see what's up with all this...

I'm ordering the parts for mine now from Focusrite and they have these available for the 4i4: Part Number: SEMS002022 (U27) Description: STEP DOWN CONVERTER SYNCHRONOUS 1A MP2141NGTF ADJUSTABLE "MPS" Part Number: SEMS002049 (U31) Description: XU216 QFP128 CPU 256K RAM 2-TILE 16-CORE 1000MIPS ENCRYPTED Part Number: DDES001001 (U33) Description: DIODE SOT23-6 ESD PROTECTION "SEMTECH" RCLAMP0504S.TCT Notice that 2 are the ones you replaced. They also mentioned a service bulletin for the 4i4 3rd gen so trying to get a copy of that as well which might provide more insights.

Oh wow that's the first I hear about a service bulletin, let me know if you get a copy of it !

well, in my measurements, it's a relatively short peak, and on average it is definitely below 900mA. I expect high inrush scenarios like this are handled quite differently depending on the hub. Also, with 3A peaks, voltage drop over the cable and contact resistances is also noticeable. I could've gone into more detail on my current measurement (resistive shunt) which also affects the peak amplitude and duration.

You're not wrong. They saved a few pennies with bargain bin components, a few years later most of these are probably in a landfill by now. Thanks for watching anyway !

Thanks for the comment. A few reasons : I've mostly stopped doing Nissan stuff; the last RE videos I published weren't as successful as I hoped, and spending a full day making a video for 2-300 views is not very motivating. I had some other non-ECU-related RE projects I was thinking of making into videos, but out of respect for viewers I'm not going to post an uncut 2h stream of me rambling mostly wrong assumptions and deductions; and editing takes time....

@@fenugrec5697 yeah I get it man. For “us” motivated learners, the 2 hr ramblings may be worth it though, but I understand where you are coming from. I just spent an hour finding and digging through PIDS on another Isuzu Ecu. But the Ecu didn’t disassemble well enough too really show the usefulness of finding the PIDs, so now I need too go through and get ghidra too disassemble properly. I finally just shut the recording off and am doing something else now. I do wonder if I should just post the videos anyways though. It would really dilute the value of your channel, but at this point with how few channels there are, viewers still might find it worth it.

@@GHIDRAuto I understand them. I know that these types of topics are not of much attraction to the public, taking into account that they are not topics of a person's daily life. However, I know that there are many of us who are grateful for your publications and we encourage you to continue publishing. thank you.

@@Stack28x3 thanks man! Yeah life has been busy, I will hopefully start making more videos soon. We will see.

A single zener isn't ideal for this : you would want near-zero conduction at 3.35V, and "full" at 3.5-3.6V. Low voltage zeners have a very soft knee, look at datasheet curves for example BZT52* or 1N53* . Also, power rating would be a challenge, since a shorted buck regulator means the zener is conducting between VUSB rail and ground.

interesting, I thought the whole 166x series was mostly hardware-identical. The network controller should be on the mobo ; large PQFP-160 IC, labeled DP83934 . You would also have to verify the pinout on whatever ribbon cable or connector for the LAN option.

via AUD with special hardware, or with an OBD cable and nisprog

hm, I don't know if it would be worth the cost of shipping twice those fairly large and heavy instruments ...

Thanks - yes, I eventually realized that it would most likely take a whole new membrane, that realistically would have to come from a complete front panel. Luckily I don't really need that particular button so it will probably remain unrepaired; I just taped over the hole so dust and debris doesn't get in.

not systematically, beyond the known-problematic caps in the power supplies that I already replaced even if they looked good. A full recap would be wasteful IMO

From the datasheet : "built-in fan with fan speed control"; from the RSP-1000 schematics it's modulated directly by the sensed output current, but the fan is always on even with the "REMOTE ON" shorting plug removed.

@@fenugrec5697 Thank you for your quick response! I received a new one (RSP750-48) today and can now say that it’s true 😕 To me it’s way to loud even with no load connected. Do you have an idea how to reduce fan speed on the controller/ board? I could also change to Noctua fans which are quieter… 🤷🏼‍♂️

@@Chris-sc3rf The smaller the fan, the stronger the correlation between "noise" and "airflow"; you can't win. Of course you could tweak the fan control, or re-engineer one like I did for a GPC-3020 ( th-cam.com/video/3FC4myguLyw/w-d-xo.html ), but when providing any kind of power, your PSU will generate heat and need sufficient airflow. You might rewire the REMOTE_ON switch to also disable the fan, but that's not great: if you run full tilt and then turn off - lots of residual heat, not good for reliability.

@@fenugrec5697 Yes that’s true. I can’t half the airflow without impacting the cooling. The load I will connect is dynamic with a low duty cycle 30-50% (SSB power amp) so I hope it will work… I will check with an electronic load if the airflow is sufficient. What I really don’t like is the fact that the fans are controlled by sensed current and not by the actual system temperature 🙄

I don't know , it's "repaired", not much else to show ?

google "rsp-1000 schematics", should be easy to find

FYI I don't remember if the V- terminal is bonded to chassis ground ; if so, they cannot be wired in series. The datasheet doesn't say it can be done, so assume it can't, unless you can thoroughly review the schematics to ensure it can work. For operation in parallel, the RSP series isn't specifically designed for load sharing (some more sophisticated models are), so YMMV. Good luck !

Measuring capacitance and ESR in-circuit can always be problematic, regardless of the instrument used. But for those capacitors that seemed "good" even out of circuit, I'm not sure what measurement would've revealed their defects... Different frequency ? Leakage at nominal voltage ? It would be interesting to dig deeper. The Peak is a simple instrument, I'd be curious to try other similar small / convenient testers but it's all I have.

@@fenugrec5697 I'm not sure how applicable it is here with the relatively low voltages, but I notice with tube equipment that you really can't know how leaky a cap is until it's tested at its rated voltage. Those little ESR meters are great tools, but I find it useful to have another leakage tester that can go to a few hundred volts for caps that need it, such as the Heathkit IT-28.

Can you name a few of these "modern options" with equivalent specs that aren't 2k+ $ ? I wouldn't mind something smaller and lighter than this monster, but the modern alternatives are at least 4-5x more expensive than what I paid for this.

​@@fenugrec5697 I feel like you're not genuinely interested in a real response but are more interested in defending your purchase. And that's fine. I think your "out" to what would have been my next reply is going to be the "equivalent specs" wording. No matter how I reply or how close the specifications seem to be, I feel like your response is inevitably going take a contrary and argumentative stance which will ride on that phrase's proverbial back since your first response's tone is already rooted in that direction. My question as well as my interest was genuine and I do not have the desire or motivation to argue or validate your purchase. I was simply trying to understand the purchase logic as I am in the market myself.

@@Wil_Bloodworth I don't mind discussing it - it would've been easy enough to simply ignore the comment. I would lie if the challenge of the repair wasn't part of the interest, but I think my point still stands - getting comparable specs, in a new model, is much, much more expensive. ( my research = 5 minutes of looking at rigol and siglent lineups). Some 50$ bargain-bin alternative might exist (I have in mind typical single-chip DDS bare boards that can be found on... "international shopping sites", but I don't expect the specs would compare favourably at all. I'm not aware of a middle ground, but would gladly be proven wrong. I don't even have space on my bench for this machine, I store it in a separate room and set it up on the floor when needed. But that inconvenience doesn't amount to 2k$ for me. So, 3 points : specs per dollar, total price, and repairability.

maybe, I didn't pay much attention to the CAN implementation on these.

@@fenugrec5697 I checked out your GitHub for Ghidra helper scripts and am working with an SH27531 which I don’t see the regs or ivt files for. Should I just reference the data sheet to create those registers / labels for the script or does the python script also do other helpful things?