Please never change the way you make your videos. I love the clicking of pushing the button between each shot. You always stay calm and explain very slow and clear. This is really educational for people who are not an expert in electronics.
I guess I'm extremely bored so I watch old videos. You are one superb technician. I really enjoy your videos. I think I learn something every time I watch. Thank you for the videos. I'm just an old retired technician. W Rusty Lane K9POW in eastern Tennessee
Its even rarer to see that someone mistake inductors for caps (the green parts were marked with an L in some places) on a board that had the rare PCB failure (the only way I could think that pattern of cremation could occur.)
Amazing Job Sir. Most would have just told the customer it needed a new board and if they could not afford it. Told to sell it as a parts radio. Amazing skill sir. Well done. 👍 73.
Better than a new board. That was a really nice repair. Very complicated but the finished result was perfect. Always learn something new from you. Danke Peter.
Again a great repair job by Peter ... He can be entrusted with repairing any radio ... hats off gentlemen ... 73s de DL6RDE/AA1KD, Karl-Heinz "Charlie"
Hi Peter, good job. I have a little addition to setting the idle current process. It's in my opinion much better to do this in DIG (not PKT) mode than in SSB. DIG is the same thing as a SSB (LSB or USB, can be set somewhere in the menu), but the radio expects modulation from the 6-pin miniDIN socket on the back (which is in fact low impedance line input) EVEN if you press the PTT on the microphone. So if push the PTT on the microphone in the DIG mode and you have nothing connected to the 6-pin miniDIN socket, you are in fact transmitting in SSB mode with completely muted microphone, which makes setting the idle currents much easier and precise.
A great repair and carried out very professionally. The test equipment is very interesting also. Super video. Thanks for letting us all look in. 73 de GI8WFA and stay safe.
I watched a lot of TRX Bench the last years. These videos really are electronic detective movies with always a good outcome. Told by a calm person. I really can sleep well to this videos and also learn something. Compliments
Hi, thank you for this very interesting post. I imagined changing an MCU to be much more difficult. I find your approach to error analysis (also in the other videos) super and very instructive! Many thanks for this. vy 73 Andreas, DL5LC
Glad you went ahead and fixed it. That radio is no longer in production and factory repair isn't really an option. 857D is my favorite "swiss army knife" radios of all time. Especially with a wide band collins filter.
Great job as usually dear Peter. I had the same problem with Icom 775's the PA final stage ; I rebuild with new PCB burned zone. As in your case, there was a loss between 13.8 volt and GND traces with a huge current between. I think this can happen with the PCB heat or humidity, I don't know exactly. Best 73s and thanks for sharing. Pasquale IW0HEX
Once again a nice radio has been safed, good work indeed! I guess the cap shorted out, an the owner could be happy that the short stopped while burning. There was enough material left to give it a try, and you succeeded. Peter, may you plan to collect the charcoal from all the burned radios? You can get a nice diamond if you press it hard enough ;-) Just kidding. Nice video, good work. 73 de Olaf, möge der Sommer endlich kommen!
Thanks Olaf, yes I'm doing this job only to collect enough charcoal to start a diamond production one day lol. Ja nach all dem Regen und Unglück hoffen wir das der Sommer beginnt. Hoffe Du bist verschont geblieben von den Fluten...73
Very nice video! Glad to see that you did not give up on that board! I worked in commercial comm back in the states for 20 years and was a dealer for Uniden commercial radios back in the day. They were fairly reliable however those little green caps on the final were always junk. As a habit we always replaced all caps around drivers and finals but to comply with warranty work we always sourced from Uniden. Is there an EU supplier for these caps? I have a first gen 857 ( not a D model) and it is probably equipped with same trouble makers. It might be worth my time to replace them as a preventative measure. I don't know if that final for the original 857 is available still, if not a ounce of prevention is better than junking the whole unit if that PA fails. A word of wisdom from past experience. Try to clean off as much of that carbon from the board and reseal the area with a high voltage corona dope. That carbon is conductive and can cause some issues. Take care and keep those videos coming!
Hi Peter it’s good to see your videos again I really definitely enjoy them. And you did a fantastic job on that 857, actually your repair job looks better than the factory I’m very muchly impressed. And how you are able to work with the SMD is phenomenal. Hello from the Texas hill country. 73 WD5ENH Steve
Nice a very well explained repair as usually peter. Its always a pleasure to have a sunday with one of your funny videos. Thx for your time, always learning something. Many comments and few likes, come on boys!!
Peter super repair Good Job you saved the customer alot of money as Yaesu wouldn't do that repair they would only sell you new board which would cost $700.00 or more maybe suscessful repair well done :)
beautiful repair....... you do the repairs the factory would not do , that is why I love your videos . You truly are a master technician . That is a repair I would also attempt myself , though probably not as nice looking as yours hahaha. Many thanks.
Remove the screws before unsoldering transistor would help with the heat transfer to the heatsink while removing it. It will save the traces on the board.
Such a part of the burnt printed circuit board must be cut out with a cutter or dremel and the conductors must be restored. Otherwise, high-frequency voltage will constantly break through here. Good video. Like.👍
Good Job and happy radio owner, better than a surgeon.. i know sometimes it's not easy find a replacement part such as special cap for UHF, maybe a NPO cap can be used. What do you think about "short killer" device for you lab ?! Regards'73 .
Yes you are right getting components is getting more and more critical. Even if you order by the manufacturer it happens that you get a back lock info of 8 month. So happened actually with a Icom IC 7100...
You are right about the factory would not repair this kind of problem. I work on somewhat similar aviation equipment. I could not get away with this kind of repair due to the nature of use. My own stuff I will and have. I knew that something else caused this failure. this is good education for all of us.
Maybe the 1st in yrs. that I would have gone one more step . Grind out the carbonized fiberglass , and then fill in fiberglass powder / epoxy . I am more of a mechanic , not as much of electronic technician as you ? Thanks again
Thanks for comment and yes that would be a good idea but since we have a multi layer PCB it is very risky to grind it out. With the new bridge wires installed we have it somewhat solid and from my perspective it is the maximum we can do...
@@TRXLab I would have still filled the crater with epoxy just for the insulation from the burnt fiberglass. I used to repair very high horsepower AC motor drives, I often got in final boards that had burnt spots the size of a nickel . If you didn't clean every last bit of black out of the hole it was guaranteed to come back on you as a warranty repair. I kinda miss that job, one of the few jobs were I got to stay in one place and just work on broken stuff. My training is radio repair in the USAF so anything with RF interests me. Good job getting that final repaired. I would be interested in seeing how long that repair lasts.
Hi Simon, good to see you! The internal SWR bridge does a quite good job to prevent a PA failing by high SWR but trying to match a bad antenna creates sometimes very hight voltages or simply the cap got a crack and starts burning under high voltage..you never now 100%..
I would have liked to see the testing of the individual components that were questionable in this video; I know it would make it longer but I think it would also make a better training video, in order to make it more thorough as well, to make it more informative as well.
Thanks Peter, great video as always. I don't think my FT-817 has a Smoke Signal mode, at least not what I could find in the menus (which is probably just as well). I'll stick to CW as my lowest common denominator. 73, Jan Henkins - M7HNK
Smoke signs ... Great! This is what makes electronics related videos go viral :) :) ... and I instantly had a lol when I saw the big inline fuse on the power cables :) ... there is nothing like safety:) Now one serious question, why not remove the screws Before applying solder ..it's less thermal mass hence faster soldering ... just saying ...
@@TRXLab Of course, but I was referencing the part right at the begginning were you were removing the blown out power mosfet. a simple minor thing really not at all an issue specially because you have great top of the line tools for soldering and desoldering. But I prefer to remove the components with least possible thermal mass around then. BTW Great Video and you are totally right ... such board can perform for a long time and any brand would classify that board as not possible to repair ... Well it seems like the right to Repair movement is going Global and getting a lot of traction* ... * (and yes this last sentence is a pun intended for John Deer farming machines :) ).
@@John_Smith__ Ah okay I see, of course you are right John, but as long I don't feel the pain as the power of my soldering gear is powerful enough one don't think about that.
It is supposed to do that! That model was intended to take us back to our roots. Smoke signals. That is how you communicate with this device. (Ya, right!) ;-)
I have an 857d thar recently started behaving strangely. The heat sink gets warm while sitting in receive, with a noticable higher noise floor. It was suggested that the PA relay may be stuck closed and there is PA idle current flowing. Is this something youve seen before?
Hola Peter, tengo un FT-857D que calienta mucho en VHF & UHF con carga de 50 ohms independientemente de la potencia hay mas de 40 grados centigrados sobre el disipador, V/UHF Idling Current Adjustment seria una solucion? mil gracias!!! exelentes tus videos, saludos LU1DVH
Also...ich als deutschsprachiger freue mich ja das Du so langsam sprichst...so verstehe ich alles.Aber für nen Engländer muss das ja echt gruselig sein....Ich habe mir schon sehr viele Deiner Videos angesehen und bedanke mich auch für dieses recht herzlich
If you have the right tools and equipment, you can do these repairs good! And these days repairs are not done, because a new trx or in this case a new board is much cheaper than all the labor required for this repair!
I think the through hole plating on the 12V line to the final could not handle the current. especially if no solder was flowed through the 4 holes. This would cause the "Toastiness" and slow burn. The film capacitor was just there for the hot ride. PooF'
@22:11 question for you. Would you have taken the time to remove the carbon from under the trace, then epoxy the trace to the undamaged part of the board. I am asking this question as I am watching the video so you might have already answered the question.
Similar issue. Mine has has lost it's full 50w/20w vhf/uhf output as well but still puts out milliwatts. Had a slight burning smell just prior to failure. Any thoughts? 73
hi Peter nice video and content as usual! IMHO I’m used to recover from bad shape vias or trough hole connection introducing a piece of copper bonding cable for one side to the other one and solder whenever possible the cable on the pads where the via comes out… I don’t know if you really get what I meant due to the poor explanation. By the way I really envy your deep knowledge and expertise! Keep on rocking
Hello, I was watching this again and was wondering if you have made a video on the FT857 that had lines going through the display ? I have 2 FT857's and one developed lines through it,,,, if you have done this could you reference the video number ,, Thank you Ron AC7RH
Hallo Peter super Video ich suche eine gute Werkstatt für meinen 857d das er wieder Fit bzw abgeglichen wird hättest du eine Adresse für mich Viele Grüße Thomas DD4ST
I have a FT-857D that I paid $715 for, how can Yaesu charge for one board? Replacing the VIAs with solid wire is standard operating practices. Where is all of the is high Voltages (requiring high Voltage capacitors) coming from? 50 Watts into fifty Ohms in no where near high Voltage. Ron W4BIN
To swap out the board is quite expensive. High voltages coming from reactances since we do not have a real output resistor in ohms. The impedance is a complex resistor which gets critical if you get to resonant points...
