Відео

The PIC has separate protection bits for different areas of the Flash. I would have your friend try to read anything he can from the old chip. If he can get the bootloader, then you can download the hex file for the rest of the firmware. Most likely it's all protected, but there is a small chance they didn't protect everything. If you read the Flash and it's protected, you will get all 0's or all 1's (can't remember). Most USB EPROM programmers can also handle PIC chips. I might try changing that HC14 Schmitt trigger IC, as the soldering looks horrible. The input to the PIC should be a steady square wave, not what you seemed to have, with the longer low time sometimes. Perhaps the PIC doesn't like what it is being fed. Maybe the firmware checks to see if the freq of the input is steady, and rejects it if it's not. Good luck. Another idea would be to remove the HC14 and feed a nice 0-4V square wave into pin 6 IIRC of the PIC, through a 1K resistor just to be extra safe, and see what happens. Keep the frequency low, like 1 MHz, so that the 1K resistor doesn't mess it up too much.

In fact, there is a lot of programmers for PIC microcontrollers, you can also easily build your own (as long as you have a PC with a RS-232 port), but. The main question is if the PIC is locked or not. If it is not locked, then it is easy, just read the firmware from the broken chip and burn it into a new one, but if it is locked, then this is no more an option. I looked at that fimware update tool. I am not familiar with M$ Window$ (in fact, I'd never used that thing), but it looks like it contains strings with something, that looks like a content of an intelhex file, which, in my opinion, is that firmware. I am almost sure that if you find someone who is familiar with Ghidra (or similar tools) and all that Window$ stuff, then it is possible to extract that firmware from the update utility, furthermore, I think this could be relatively easy job.

Great challenge you’re facing 😊 Dealing with PICs is t something I particularly enjoy, so I stick to tubes 😊 I was hoping the CMOS IC was the issue because at least you can then deal with it simply, but no … that would have been too easy 😊 Good luck 🤞

Hello Stefan, if your friend with more PIC knowledge have the CCS Pic-C compiler, there are a couple of bootloders available that can be used to program the PIC at first time. I have programmed PIC´s in many years, but never used bootloader acctually as a developer you always have hex file. Then there is a question about the EXE program you got if it is able to communicate with the bootloader from CCS or if it is another bootloader, ther are a copule of PIC develop softwares that maybe have different bootloaders but CCS is a certified Microchip dealer so it´s good chans there boatloaders will work with your EXE. If you got stuck , maybe i can try to help you to program a bootloader on the PIC18 you have. // added info I checked my CCS compiler and i have bootloaders for PIC18 , it uses A5 for activae loader on boot but i think it can be removed so it goes directly to load at first startup, then then there is a choise if program should load in bottom or Top of chip and baudrate to use, standard was 9600 , the easiest way for me to test is to get a copy of your EXE file then i can try different setup until it loads from the EXE file, if you need the help. 73 Peter

Good to see you Stefan. I'm looking forward to part 2 of this repair. 73 OM

Stefan- The very large toroids sometimes crack the solder joint during shipping. MFJ did not hotmelt glue them down. So sometimes you'll find these have been resoldered. This won't fix the issue of the vid, but just an FYI. I also found while working on these, is a lot of wave solder flash/splatter all over the board & sometimes that flash will lay on the IC pins.

lots of PICs fail in the MFJ antenna tuner products. They have no shielding and they are close to the power RF parts. If that friend of yours can trick that PIC to be readable (very-very small chance of success but i've seen cases that it could be read in certain conditions - for example higher Vcc could "unlock" them - at least the older versions), then the HEX could be read and transferred to a new PIC. But before that, try to borrow a good PIC and test the tuner with it, to be sure it's working. Since MFJ is out of business, maybe another company is doing their warranty work.

It may be possible to dump the PIC program with a programmer like TL866a. It should be also possible to program a blank PIC with the same device. You need that the devices list include your PIC of course and a TL866a as well. As your PIC is failing, as it seems, only on the counter function, you may be lucky enough to revive it. I wish you will be able to post a successful part 2😁

Guten Tag Stefan. One problem is pic processor have a bit which can be set to prevent the code from being copied. I understand the idea but it makes servicing next to impossible. Living in the US, it was widely announced MFJ was going out of business months ago. I had hoped another interest would buy out the company assets and carry on support but I have no info on any such arrangements yet. It seems your pic may be working since you were able to invoke several options successfully. I'd be very surprised if the pic is the issue, especially since you updated the firmware. Did you happen to notice the original firmware level and the level after the update on the display. As a general rule processors either work 100% or totally dead the VAST MAJORITY of times. Maybe I'm confused but you did show the input signal to the pic was intermittent and other issues like a missing R and a very sloppy installation of the IC next to the PIC. Based on what you shared, I'd replace the R then check function and if no joy, then remove the sloppily installed IC, check the pcb traces in that area and maybe replace that IC. All of these steps should be executed before worrying about the PIC. I will look to see if there is any new news regarding a new owner for MFJ and report any possible news to you. Personally, when I have had people send me projects which were already messed with and messes created by someone else, I send them back. Life is too short to waste precious time on others failures. IMHO. 73, WA4AOS, Glenn

Hopefully your friend will have an answer. I have zero experience with PIC microcontrollers, but as yours seems to be mostly working perhaps it is possible to copy an image of the software from it to the new chip. Regards, David

Best of luck Stefan with finding any help from MFJ *(Manufacturers of Fine Junk)* MFJ are gone out of business some time ago. I prefer my manual tuner/matcher, nothing much ever to go wrong. 73 Stefan

Can you also reset the test counters?

Nice Work! Keep going. Thanks for sharing it.

Hello Mr Stefan. I have a second hand 605 and when i switch it on everything is ok. After 10 minutes (i guess when capacitors are loaded) the beam becomes thick. Like the oscillation in your video. Do you suggest anything i could do ?

Stefan...I've had very good success getting parts from companies who don't sell to the public by asking for a handful of product samples...It's worked every time so far for everything from microwave capacitors and noise source diodes to panel lamps for scientific equipment repairs....Great work...keep it up...!

Sprich Deutsch, Mann! Das ist ja zum fremdschämen.

Verstehe ich nicht.

Stefan, kann Dir nachfühlen. Der Ehrgeiz, das Gerät bis auf die letzte Schraube in neuwertigen Zustand zu bringen, lässt einen nicht los. Aber ich denke, hier hast Du einen sehr guten Zeit/Aufwand Kompromiss gefunden, hier nen Haken an den "never ending story" Transceiver zu machen. Was geschieht nun mit dem aufgeflitzten FT221 ? Bin auf Deine nächsten Videos gespannt ! 73, bleib gesund, DL1lAJ Andreas

Danke, sind immer wider sehr lehrreich Ihre Videos

Congratulations on achieving success. The more difficult the project, the more satisfying the reward at the end. I appreciate you sharing the process with us.

War wieder ein sehr interessantes Projekt, habe es wie immer aufmerksam verfolgt. Danke für deine Videos Stefan. 73 de Herbert DF8RU

Hello Stefan - I admire your skill and patients.

Phew! What a long one...bet you'll be glad to get back to "less challenging" repairs! 73 - Dino KLØS

Thank you Stefan. It was very educational following your work.

ein schöner Abschluß. Stefan 73 de OE8XKX

Rodriguez Mark Davis Kevin Harris Linda

When inserting back into compartment, do not insert battery all the way in. Just enough to close the top, this way you don't pull on the board next time just pull battery a little at a time on each side and it will come out. Make sure you test it, plug can fall off when inserting back in. Use vaseline on gasket for a tight seal.

I was thinking about terminator 1000. "That's it you're dead!"

So many capacitors, I am definitely not looking forward to it. Thank you for sharing! 73, KD2TDE

That's an interesting problem. I recently got one of these (mine does not have an A at the end) and the positive half of the sine wave seems to be clipped a bit. I am going to look into it so I appreciate you recording this video!

"Sounds of Mungo Jerry in the background, very relaxing." You are droll! Amazing restoration, great creativity.

Wo bekommt man denn eine Ersatzbatterie für das PLB1 her?

Good job. Enjoyed the 260 cap tests.

After replacing the battery, you should use the test procedure to make sure everything is ok. One more question: where to find the replacement gasket?

Great work Stefan. I did not know the probe loop trick so thank you. From hot Tempe, AZ USA

This was drilled into us at Motorola and Kenwood to RTFM and understanding how the radio works and how to enter proper alignment modes. I went to another shop after the one I worked at closed down and was appalled at the bench tech as to how he aligned the Motorola Maxtrac and Radius line of radios that were popular some 20 plus years ago! Instead of using the computer with alignment software to set up the radio after a major repair he would just twiddle the caps and coils until the radio worked. Now the radio would come back time and time again for alignment issues. I was the low ball man on the bottom of the totem pole so I kept to myself. This was not the way to align these radios! Software controlled radios are a different beast compared to legacy Motorola and GE radios that had zero microprocessors in them. Funny I had fifteen years experience on these micro controlled radios and could have solved the problem in about an hour and a half of realignment by the book.

Thank you for the wonderful advice. I almost switched the speakers to my primary pair after running the hot amp for 5 days, few hours each day. Didnt realise on the lack of internal protection system eventhough i opened the cover to visually inspect the parts. What a great series, enjoyed every second of it. Thank you for taking the initiative and putting in much effort to share it with everyone. You probably saved my speakers that I intended to run the amp with.

Hi Stefan, excellent result after an arduous search for the root problem. I also have a Yaesu FT 857, I opened it and removed it (the conductive heatsink) Greetings from Chile CA5JXT Jaime 73.

Something about KENWOOD that just gets my attention. Is it live, or is it Memorex? I mean KENWOOD!

Contrary to the manual can be best, I agree with vertical alignment. Also the accuracy comments in the manual are stupid. It's more accurate in the first half of the scale, not over the whole scale. Manual says use the most scale you can, if you check it, that's wrong so you are correct to think and not blindly follow the manual. Weather stripping for the battery it GREAT. Keep up the good work.

Great videos Stefan, from Tempe AZ

Hi Stefan. Pardon me for saying you look a little tired after this fix. Thing is, this is the true satisfaction of using you educated skills to repair a broken instrument. Take a break now, collect your wit, and forget about the battle for awhile. Cheers from West USA.

thanks for sharing this very valuable video I can use it for my R4B

Manmanman Stefan, da hat man Dir aber wirklich ein faules Ei ins Nest gelegt ! Ich bewundere Deine Ausdauer, manch einer hätte das Gerät schon längst über den Jordan geworfen und wär zum nächsten Funkhändler gefahren, um sich was schickes neues zu kaufen. Die Herausforderung, das Ding zum Laufen zu bringen zeichnet Dich aber als wahren Funkamateur aus. Eigentlich hätte man das Gerät einem angehenden Funkamateur in die Hand drücken müssen, um sich im Technikverständnis zu beweisen. Es gibt kaum ein besseres Anschauungsobjekt wie diesen faulty TXRX der zeigt, was für HF- Fallstricke einen überraschen können. Drück Dir die Daumen, dass der FT221 Reparaturbericht im einstelligen Bereich bleibt (obwohl es ja immer spannend ist, Dir bei der Arbeit zuzuschauen 😉) 73, bleib gesund von DL1LAJ Andreas

What an unusual problem, transformer failure is way down my list of suspects. Guess you got lucky (???) I have not seen that glue used on transformer windings but have seen plenty of damaged components and PCBs. Hopefully the alignment resolves all PLL issues - looking forward to part 9 and beyond 😀. Regards, David

that corrosive glue killed more transceivers than operator error. The solvent dries out, becomes porous, absorbs moisture, and eats away the insulations, even the legs of the components. It's a well known problem in Yaesu and Kenwood transceivers made in the 70-es and 80-es.

Thank you for a great video. I follow.

Good morning Stefan, I live in London, I have a Yaesu FT-101Z, would | be able to send it there for a complete inspection and alignment...

Good morning Stefan, I live in London, I have a Yaesu FT-101Z, would | be able to send it there for a complete inspection and alignment...

Hi good afternoon, :This is KC2DPY. I have the same tuner but when my radio has the preamp on its do not tune,any suggestions.