Yaesu CD-41 Fast LiPo Charger Repair

Рет қаралды 8,126

9 жыл бұрын

In this video, I track down a fault in the CD-41. The failure mode is no charging action as well as the green 'Full' LED always lit.
Please note that this is about how to approach such a repair. If you are merely interested in protecting your own charger or repairing it, there will be a write-up.
Lastly, if you have a CD-41, I would be very interested in knowing whether Yaesu fixed the problem in your unit, as this appears to be a design flaw.

Пікірлер: 58

@martinvanek5951 11 ай бұрын

Thanks so much for taking the time to solving this problem. I purchased this charging base in 2017 so I suspect Yaesu didn't fix the problem.

@dougn7bfs 4 ай бұрын

Thanks for taking the time/effort on this video, saved me having to reverse engineer the one that I have that exhibits the same symptom.

@rvscootin3457 2 жыл бұрын

Absolutely OUTSTANDING!!!! Great troubleshooting and analysis. As soon as you drew the MOSFET. I thought ESD Zap! Thanks for a great video. Now I need to go fix mine...

@raccoonnyc 8 жыл бұрын

That was no easy task! Trying to reverse engineer what appears to be a fairly simple circuit can sometimes be a nightmare. Nice job.

@22844Norderstedt 5 жыл бұрын

Excellent Investigation and good pesentation. Thank you. My CD-41 failed with same problem, I bought a new one, received two days after order ! I fixed an ESD-Caution-label on the loader. TNX+73 de DC2FK, North-Germany

@jackcrusan 8 жыл бұрын

Very good troubleshooting!!! Excellent video.

@MrBobber01 7 жыл бұрын

This was an excellent video. I was able to repair my CD-41 with the ESD mod and things are working great. THANKS!!!!!!

@RupertHandford 8 жыл бұрын

Great bit of investigation there. Thanks for sharing

@jim293 7 жыл бұрын

That is a very well done explanation. Thanks so much.

@froby_flingit 6 жыл бұрын

Thanks for this video, I just ordered that same part, going to try to replace it with my Hakko soldering station, wish me luck.

@MrCircuitMatt 6 жыл бұрын

Brian Frobisher good luck!

@lbreuss 5 жыл бұрын

Yaesu fixed it: As of 2019/08, the charger comes with a patch: Diode P6KE18 soldered over terminals of GND and Sense spring. This is a very fast Diode that should be able to absorb any transients on this contact.

@MrCircuitMatt 5 жыл бұрын

Hi Leo. This is great news, thanks for letting me know!

@ik3itxgab339 2 жыл бұрын

nice research and repair job

@randythomson2179 7 жыл бұрын

Good video. Haven't replaced the MOSFet yet, but I'm confident that will fix the problem. FYI, I purchased mine with an FT2DR radio in 2016. The circuit is still the same. The P/N stamped on my board, is KP-235-35, same as yours. I'll be checking out your ESD protection mod. next.

@MrCircuitMatt 7 жыл бұрын

Awesome this is great news. It's a shame they haven't improved on it but at least it's an easy fix. Thanks for watching.

@felixcat4346 8 жыл бұрын

Very good presentation and explanation. So, ESD caused a working unit to stop because someone touched the metal connectors. This is good to know if you like to dabble with power supplies.

@MrCircuitMatt 8 жыл бұрын

+Joseph Nicholas Exactly, at least that's my theory. I have a follow-up video on implementing proper protection since simply replacing the transistor will not prevent this from re-occurring. But I guess you found that video already :-). Also I really should get that write-up out.

@pkyvr 5 жыл бұрын

Great work!

@TomTechVideos 2 жыл бұрын

The battery middle terminal is not a resistor or NTC. It is connected directly to the battery + terminal (resistance below 1 ohm). From the circuitry it looks like the middle terminal is only detecting that a battery is present if the middle terminal is connected to the + terminal, then giving some bias current to the Darlington transistor pair to start charging. I recently bought this charger and it is not broken. I just wanted to analyze it to see if it will break my battery and/or start a fire. It is really scary, there does not seem to be any battery temperature protection or battery over-voltage protection in the charger. I hope the battery has an internal one, it most likely has. The green led goes on only if the charging current goes to zero, while the middle terminal is still connected to the + terminal. At that point the voltage at the battery + terminal and middle terminal will be almost the input voltage (12V). Scary! The use of MOSFET and high resistances at the middle terminal is probably because the leakage current will be minimal if you leave the battery in the charger while it is not plugged in (to the 12-16V supply). Oh and by the way, the input over-voltage protection is insanely high. It kicks in maybe after 19V or so. (The zener is maybe 18V) So the 16-19V range is unprotected and forbidden.

@MrCircuitMatt 2 жыл бұрын

Thank you... I cannot really check what's hooked to the middle terminal (always kind of suspected a thermal fuse there but I don't know). If any of the things you mention are true, though, that would be somewhat crazy by Yaesu. Sadly though I really wouldn't be surprised if that is exactly what they did... thanks for your comment!

@mortenrolsing7137 8 жыл бұрын

Super cool video, i realy enjoyed it, thanks. I hope you will make more repair videos, and share them with us. :-)

@PapasDino 8 жыл бұрын

Great analysis and fix! 73 - Dino KL0S

@budleyca1 8 жыл бұрын

Very nice...

@daveys 6 жыл бұрын

Hi Matt, thanks for the video. I recently bought an FT2D secondhand and that unit works OK but the battery appears to discharge while running in the cradle, hence me stumbling across your video. It’s a bit cack that a company building kit such as Yaesu would build something that was so likely to fail in normal use.

@MrCircuitMatt 6 жыл бұрын

Thanks, my thoughts exactly :-)

@BrekMartin 6 ай бұрын

The SBH-52 that replaced the CD-41 is a different layout. It has an eFuse in an 8 pic SOIC package, and I don’t believe any FET pin is directly connected to the middle terminal.

@MrCircuitMatt 5 ай бұрын

That is good to know, thank you for sharing!

@borayurt66 5 жыл бұрын

Great video, good work! Did you ever took the time to combine those pieces that you reverse engineered together for a full schematic? I have a "chinese clone" yaesu cd-15a charger (for vx-7) which seems to use pretty much the same circuit inside. I have a different problem, it cuts the charging too early, maybe, if you have the schematic, I may come up with a mod. Thanks!

@MrCircuitMatt 5 жыл бұрын

Thanks. I did not put the pieces together but Sándor Végh did and posted the schematic in the comment section to the other video I have on this topic (kzfaq.info/get/bejne/rcWaeaeEyJunlmQ.html&lc=z231fpexhnvssngcyacdp434doilpl2edjgzc3zsoipw03c010c). The direct link to his work is here: drive.google.com/drive/folders/1e7Nx7F1V4SH04VfODBhC_F9s9TEpUSPa?usp=sharing

@bertolo75 8 жыл бұрын

Hi. Can you tell me what is the positive for charge? The positive is PIN near to GND or is the fafrthest? I neen to connect a battery charger professional (with CD-41 modified) for slow charge. Thanks 73 de in3elx Roberto

@BrekMartin 6 ай бұрын

This is replaced now by SBH-52. I wonder if they changed anything?

@froby_flingit 6 жыл бұрын

I just found out my issue is with my SAD-14B wall wart that came with my FT2DR radio. I purchase a brand new Yaesu drop in charger and it would not light up correctly, so I purchase a Yaesu bare end cable and connected the old charger to the new cable and a proper 13.8v power supply and now the lights are working FB. Not saying there is not an issue with some of these chargers like your cool video shows, but also see if that funky SAD-14B might be the problem. WA6JFK

@MrCircuitMatt 6 жыл бұрын

Hey Brian! Cool, thanks for letting me know. I'm glad that you managed to sort it. There's definitely other things that can fail, I very much agree with you. Regard! Matt

@theend5304 2 жыл бұрын

SBH-28 problem

@fixit1000 3 жыл бұрын

Excellent analysis and repair - i am very impressed and would like to repair the one I have. If you could let me know the part number of the mosfet you used i would attempt to do the repair myself.

@MrCircuitMatt 3 жыл бұрын

Thank you! The part number of my replacement transistor is IRLML6402. There is also a companion write-up here: drive.google.com/file/d/1Xyxnbd0tBw4rz8idYSstMwOpiL0UA4ya/view?usp=sharing let me know how this goes :-)

@fixit1000 3 жыл бұрын

@@MrCircuitMatt My charger is only 2 years old and it didnt work from the time I received it. Same exact problem. So I ordered the part from Digi-key. Will let you know when it is done. Part is on back order. Thank you

@fixit1000 3 жыл бұрын

With further inspection the green light does not come on at all and the red is very dim and does not charge at all - can I assume it is the same chip with a slightly different problem?

@MrCircuitMatt 3 жыл бұрын

@@fixit1000 In this case you probably have to dive into a bit of debugging. It could be the FET but not necessarily. You could always pull the FET, test it and if it tests good the put it back in. That aside, I would first check if you have the correct supply voltage at the fuse, then check a number of other bias voltages, then check if the different transistors work as they should. This is relatively easy to do if you know how. I'm happy to help you in the process but youtube comments are somewhat tedious for this... could we perhaps move the discussion to email (I'm on QRZ) or some other means of communication?

@bertolo75 8 жыл бұрын

Inside the charger: The +7,2VCharge is S1 PIN? Is correct? (TP2 is GND)

@joemusto5674 4 жыл бұрын

Question: So if the existing MOSFET already has an internal TVS diode, all that needs to be done to prevent a failure in the first place is to install the 100K resistor in series with the center contact, correct?

@MrCircuitMatt 4 жыл бұрын

Correct

@jkb7703 2 жыл бұрын

Another Bummer is that the CD-41 will not function properly with the SAD-25 Charger supplied with the FT3D, although the CD-41 states that it will work from 10.5V (which the SAD-25 provides) ... It acutally won´t.... No green light will come on, and the battery never gets fully charged.

@marcoallevi9303 Жыл бұрын

I am using The CD-41 with a wall P.S.12V 1000mA - I then ordered a genuine Yaesu SAD 11C, that is referenced for the USA market... whatever it means... (exactly the same as the SAD-25C -10.5V 1000mA) and it works like a champ with both.

@Pedro8k 2 жыл бұрын

On my second charger may try to repair the other

@JamesSanders 8 жыл бұрын

good video, I wore a sweater yesterday, a rare thing for me, and of course, I killed my cradle with ESD probably in the same fashion. I will be digging around for a P chan Mosfet and see what I can do.. (formerly worked for IRF...) you are right, here is a Bad design with the exposed gate, could not possibly be an accident, no designer is that stupid...wonder how much Yaesu makes off of that poor design...shame on them!!!.

@MrCircuitMatt 8 жыл бұрын

+James Sanders Thanks for your comment. If the green LED is always on, just like how I show it in the beginning of the video, then my money is on that FET. If you're interested, I have a follow-up video on implementing protection, but with your background there's probably not much of interest in there. PM me with an email address if you want that write-up draft nonetheless. I totally agree on 'bad design', I'm not entirely sure about 'on purpose'. Then again I don't see how an experienced designer can let this one slip. It turns out that the FET they put in has an internal protection diode. Maybe they mistakenly thought this was enough...

@JamesSanders 8 жыл бұрын

+MrCircuitMatt thanks, I ordered qty 50 fdv304p today from amazon...its a start.. interested in the part number for the protection diode that you recommend, I may leave that out for now as it's internal to the fet (at least for 6kv, wihch is largely ineffective. I plan on fixing alot of these.. :-)

@MrCircuitMatt 8 жыл бұрын

James Sanders So sorry that I missed this. KZfaq makes it a pain to track comments. The diode I used is an EPCOS CDS3C09GTA bidirectional TVS. Not the best but I wanted to go for something that was fairly easy to source. If you come across a more suitable part I'd be interested. Thanks and 73, Matt

@JamesSanders 8 жыл бұрын

+MrCircuitMatt thanks much, I went ahead and bought a dozen of these.. 755-RSB6.8GT2R RSB6.8GT2R TVS ARRAY2 ELEMENTS . Haven't actually installed one yet, because I wanted to see if the new part held up ok or not. (I suspect the internal esd protection was left out of the original part in the first place). If the new part that I purchased from Fairchild holds up..that would be good to know and compare.. thanks again for a great video.

@froby_flingit 6 жыл бұрын

Another question, in your case was the charger still actually working? Just the lights were not functioning correctly?

@MrCircuitMatt 6 жыл бұрын

There was no charging current at all and the green light was always on. The charger did not work at all. In the mean time I have repaired quite a number of those chargers, all of them exhibiting the same failure mode and origin. Doesn't mean that it's the only thing that can break down though, but fore sure it appears to happen quite often.

@NoName-mr1lh 5 жыл бұрын

I seem to have a different problem. My charger partially charges the battery but after some time the red led flashes quite fast and I can see the current draw pulse from zero to 500mA as the red led flashes. Then when I try to charge the battery in the radio it hasnt charged very much. Has anyone else has this issue? Thank you.

@MrCircuitMatt 5 жыл бұрын

I haven't seen this issue before... the behavior of the LED seems normal (first solid, then flashing, then off) but something is obviously wrong if the battery doesn't get charged...

@NoName-mr1lh 5 жыл бұрын

@@MrCircuitMattI think I jumped ahead of myself, I let the battery in the charger longer and it did eventually go green and charge. I think I was just alarmed when I saw the current pulsing on the power supply! Saying that, when I then plug the wall charger into the radio the battery charging screen still shows two bars so it seems the rapid charger doesnt charge the battery as much as the wall charger plugged into the radio. It's no major issue, I'll just use the cradle charger for a quick charge when necessary.

@joemusto5674 4 жыл бұрын

Looks like Yaesu made some changes to the circuit, most notably, the diode between the 2 far right pins. I wonder if this is their attempt at an ESD fix? See photo: www.dropbox.com/s/zw6216egcnkhixx/2020-05-07%2016.36.41.jpg?dl=0

@MrCircuitMatt 4 жыл бұрын

This is very interesting, thank you for sharing. It could be a fix, it's hard to tell. I did talk to quite a number of radio store owners in the meantime and apparently this problem occurs relatively often. Thus it's nice to see that they are presumably addressing it, after all.