FT-817ND with the most strangest defect ever, please help !!! - Page 1
Forum section: electronics / rf-microwave

author: DC1MC
author_rank: Super Contributor
timestamp: May 04, 2020, 09:27:12 pm
content: Hello everybody, I have a FT-817ND that I want to save, it has a most unusual defect that I've never encounter it: On all RX non-FM modes, the moment I chance the frequency, something happens and the signal strength goes like 3-40db down (still hearable, but barely) and the noise increases. It stays like this up until I change the mode or the band, that it returns to working OK, and it stay so forever.The mainboard is one of the latest model and I wasn't able to find a schematic/PCB for the version005189I, the latest service manual I could find stops at version H.I#m really willing to pay for this schematic, but is nowhere to be found.Also in desperate need of ideas.Many thanks for the help,DC1MC

author: cdev
author_rank: Super Contributor
timestamp: May 04, 2020, 10:20:31 pm
content: Well, if it works okay some of the time its likely an easy, cheap repair, when you find it. Maybe the AGC circuitry is involved? Yaesu is still in business, why dont you try calling them up and asking them. It can't hurt, and there is a good chance they would know right away what the problem was and tell you. Ham related businesses are much more user friendly that way. I mean, I have no idea if they would but, what the hell.

author: vk6zgo
author_rank: Super Contributor
timestamp: May 04, 2020, 11:29:10 pm
content: I would also suggest asking the same question on QRZ.com, or perhaps eham.com.

author: trevatxtal
author_rank: Contributor
timestamp: May 05, 2020, 06:57:57 am
content: A very useful group athttps://groups.io/g/ft817/message/109368Sigh up free and learn all about your 817.I am not part of running of the group but signed up as I am a 817 owner

author: DC1MC
author_rank: Super Contributor
timestamp: May 05, 2020, 10:04:29 am
content: I have contacted Yeaesu via their contact form, I will try to call them directly eventually, I doubt if it will be of any use as, like any other company, they don't care if there is no income comming, Apple set the industry standard on this stuff.Their German authorised representatives quoted me way more than the device is worth (480EUR+VAT for mother board replacement only, no repair), so not much to do here. After the bad experince with the last DE Yaesu repair center, I would not trust anymore at all, last time I got my unit back unrepaired, missing screws and with a broken battery lid latch.I will try groups.io, maybe one will have mercy and could share the needed schematic or maybe some usefull ideas.Many thans for the sugetions and advice and if by chance have the schematic please post a link or PM me.Cheers,DC1MC

author: vk2jdh
author_rank: Newbie
timestamp: May 06, 2020, 07:56:40 am
content: Quote from: DC1MC on May 04, 2020, 09:27:12 pmSounds like the PLL unlocking or unstable. Check in with the forums suggested

author: msraya
author_rank: Unknown
timestamp: May 06, 2020, 09:54:37 am
content: Hi!Mine get a overvoltage and then PLL unit and some of the uC SPI bus strobe signals where faulty.One of these signal controls the LPF or the IPO/ATT. So, yours can be also faulty in the SPI Strobe signal and when uC send freq information via SPI bus, it also change LPF or IPO or ATT.After replace the PLL unit that was the problem with mine, it change mode or LPF when I change frequency.I need a new uC or a new control board. But unluckily, the repair boards were gone time ago.New control boards that YAESU offer me are new, and I need to change also main board to be compatible, better to buy a brand new one.So mine goes to the repair junk box.By the way. Someone with a spare FT-817 control board to revive mine?I hope this would help you.RegardsManuelEA7EE

author: dropkick
author_rank: Contributor
timestamp: May 07, 2020, 01:20:22 am
content: https://www.youtube.com/user/TRXBenchhas a few FT-817 videos. Might have something useful in them.

author: DC1MC
author_rank: Super Contributor
timestamp: May 07, 2020, 07:51:48 pm
content: @msraya Bing, bing, we have a winner, in an access of frustration I've bought a "donor" unit with the front unit gone (no power-up) but the rest is working OK, so I've used the new main unit with my front panel, and surprise, surprise, the behavior is identical.So now I have to units with bad front panels, one with f-up digital commands and a new one that doesn't start at all, I measure it and it's really strange, the MCU boots, but some port outputs are shorted to ground or the whole GPIO block G is fragged where PWR_ON and friends are.Clearly, they seem to suffer from a kind of MCU rot, I had the same issue with a 6802 in a Tek scope, most likely due to repeated thermal stress the I/O buffers get fragged, I am that >II< close to do my own front PCB with a beefy STM32F7 with better menus and features, I can do the schematic and software very fast, the layout and production is what stops me.And to make things worse, even if I can read the code from an old MCU, they are now unobtanium.Oh well, in the worst case I will connect a Blue pill or Nucleo and do a Pfuscherei to allow at last PC control, transferring reliable the flex connector will be a pleasure.I'm looking to see if there are some buffers on serial signals, maybe some pull-ups or downs may recover the panel with scrwed signals.Cheers,DC1MC

author: DC1MC
author_rank: Super Contributor
timestamp: May 30, 2020, 09:32:04 pm
content: Just in case it may help somebody, here is the continuation of the FT-817ND story:- From the previous episodes: I have two FT-817ND, one that works but has the issue stated in this topic (similar with @msraya) and another that was bought completely dead, not powering on.As I've thought the MCU on the front panel is was dead or dieing on both I've explored a number of options, including replacing the MCU or redoing the front panel PCB. None of them proved to be feasible so I've got a new front panel PCB from an Italian YAESU reseller for 130EUR + 17 shipping to Germany.The board arrived nice and shiny, and once connected to one of the units started immediately, by NOT WORKING, with a classical YAESU error by blinking the display text (not to be confused with the PLL unlock error that blinks the backlight), and having no RX or TX, the exact same error when tested on the other unit.Trying ALL possible factory reset settings didn't change anything, except that immediately after confirmation "beep, beep", the device was running for something like a second, and then coming back to blinking and being deaf. All controls were working in this state, one could change bangs, set memories and so on, and the settings were memorized OK and saved during power off.So because I don have yet a CAT cable, I've popped with the glorious Quick hot air stationthe 24C64 I2C EEPROM and transferred from the dead board to the new board, instant repair. INSTANT SUCCESS !!!The unit come alive without any issues !!!So the new panel PCB MUST be loaded with the previous content of the EEPROM, either by replacing the new with the original or the original EEPROM must be dumped and reloaded via the CAT cable, this site has the theory and command set:http://www.ka7oei.com/ft817_meow.htmlAnd there are like a gadzillon of programs to do it, or one could write it's own script for dump and restore, as soon as I get a CAT cable I will tell how it works, right now is easier to move the EEPROMs but I think every FT-817(should have a memory dump for emergency situations when the old EEPROM dies or get corrupted.But wait, there is more!!!!The dead board that donated the EEPROM was sitting there looking, so because there was nothing to lose, I decided to give it a full reflow, by doing drag (re)soldering of the MCU and all the other parts with my Metcal hoof tip and copious amounts of Louis Rossmann flux and 63/37 illegal solderand I've also put a blank EEPROM.Guess what, IT STARTED IMMEDIATELY !!!Also with a blinking display, like the new one first time, but I didn't switch back the EEPROMS, this one will be loaded via serial cable.So now I have TWO working boards and the strange defect one.As it seems the MCU is actually more resilient as it looks like, and looking on the schematic it seem that the digital multiplexer 74HC139 or the two invertors there, may be the first victim, I will 'scope the digital outputs and inputs to it for glitches. Also it seems that the digital signals coming from the MCU to the TTL logic have a rather large resistor in series !!!, it may reduce the generated noise while switching, but it will definitely degrade the digital levels.If there is a degradation of the signal path I will try to see if reducing the resistors values may help, and if not I will first reflow the parts involved and then I'll eventually replace the mux and inverters, they are really cheap and I need to exercise my hot air skillz.If this will solve the issue that I'll have an extra working PCB available to cure a poor FT-817ND, @msraya, if you still need one, let me know, you have the first choice.Cheers,DC1MC

author: msraya
author_rank: Unknown
timestamp: June 07, 2020, 03:36:59 pm
content: WooW, good news.I haven't had time to work in the PCB. The radio is sitting geting dust in a corner.I don't think It can be working again, as my problem doesn't come from the multiplexer or EEPROM.The control lines didn't work. By the way, I will try reflow as I dont have any to lose.Thank You!ManuelEA7EE

author: m3vuv
author_rank: Super Contributor
timestamp: June 08, 2020, 08:57:01 pm
content: typical yaesu garbage,built to a price not a standard,ive had a few yaesu radios,now i wouldnt have one in the shack even if it was for free.

author: vk6zgo
author_rank: Super Contributor
timestamp: June 12, 2020, 12:03:20 pm
content: At the moment, I have four faulty Icom radios queued up for repair, compared to two Yaesu ones.Currently functional, I have an ancient Yaesu & two Kenwoods which, "try as I might", I can't kill!That said, they are all old radios, & I admit I like a lot of things about the Icoms.My Icom 575A has a delightful intermittent, where it suddenly loses receive & transmit, sometimes on all modes, sometimes on just a few.I found what looked a likely fault, fixed it, & all was good till the next time I turned it on.Looks like I'll have to clear a few kilos of debris off the bench, drag the old Tek 7613 over, & really get into it.If the OP's radio doesn't have the fault on FM, maybe the answer is in those functions which are not used inFM, like AGC.

author: rhb
author_rank: Super Contributor
timestamp: June 14, 2020, 12:50:03 am
content: Sigh...After getting a 991A, I bought an 817ND for the lower power drain. I'm still not licensed again and it seems I may have signed up for another F***Tech.Reg

author: bachtoon
author_rank: Newbie
timestamp: May 05, 2021, 07:39:02 am
content: Hi all.Sorry for my English.Your troubleshooting steps are really excellent.I have a mission for you, should you accept it?I have an 817ND with a unique problem in the world :-(after a few years in its box, i turned on the device and the menu and the values ​​change on their own ...At each restart, -the contract is at full or very low with a value of 255 !, the beeps are very loud, the frequency has changed to 1.8mhz, mic gain at 0, rf gain mode activated,the led screen light off (COLO writed in menu choice !).Has it gone completely crazy? But once fixed it works fine. When I turn it off, then turn it on, again change everything ...I have done multiple reset and hard reset, always the same problem.Is it possible to put the original program back into the device chip?Have you seen and repaired this kind of problem please? Could you help me ? Thank you so much.Best regards from Belgium.

author: DC1MC
author_rank: Super Contributor
timestamp: May 05, 2021, 08:17:15 am
content: Quote from: bachtoon on May 05, 2021, 07:39:02 amHi, there is exactly ONE place where you can make a difference in the front panel of the FT-817, assuming that you've done your due diligence and measured all the voltages around (usually some capacitors die in a miserable semi short-circuit state and affect the small digital voltages), and that is the EEPROM where the settings are stored, the MCU there is long gone obsolete and has internal program memory, so when this guy is gone, the front panel is gone.So my strategy will be to first measure all the digital voltages in the front panel assembly, the service manual is superb, clear and detailed. Also, if you have a scope, try to put it on AC mode and see if during the operation there are no disturbances in the power rails.Second, put your scope on the I2C pins leading to the EEPROM and see if the I2C levels and signal shapes are OK, especially at startup, where the parameters are read from the EPROM. If you have a Rigol or some other digital scope with I2C decoding, now is the time to for it to shine.Finally, there are programs that are able to read the EPROM content for duplication, but if it's corrupted, then probably the calibration constants are lost or damaged as well, so you can replace the EPROM with a blank one and realign the device, in the end is not that difficult.Best of luck,DC1MC

author: bachtoon
author_rank: Newbie
timestamp: May 05, 2021, 08:23:49 am
content: Hi.Many thanks for your reply.Not having the necessary material to control, I am going to ask a price for a new electronic card of the front face. do you have an idea of ​​price? For example, if someone gives me a copy of their epprom, can I inject it into mine? Thank you.

author: DC1MC
author_rank: Super Contributor
timestamp: May 05, 2021, 08:32:58 am
content: Quote from: bachtoon on May 05, 2021, 08:23:49 amThe EEPROM has user preferences settings and some individual device specific settings that will not help you. The same situation if you're buying a new panel, it will be "blank" and your device must be realigned. This is why is a good thing to have a copy of the EEPROM saved for these situations.I've had good experiences with this HAM store in Italy, that was actually the only one that had the front panel at a reasonable price:Andrea Sangalli IW2LXDResponsabile LogisticaCSY & SON SRL a Socio UnicoVia Guglielmo Marconi, 721030 Azzio (VA)ITALYTel.: +39 0332 631331Website:www.csyeson.itI've paid 130EUR + 17 shipping for my panel.Contact them, they will need the serial number of the device to give you the suitable variant for it.Good luck,DC1MC

author: bachtoon
author_rank: Newbie
timestamp: May 05, 2021, 08:38:44 am
content: if I put back the same parameters of the hidden menu (menu service, ABC + POWER) is it not good?Thanks

author: DC1MC
author_rank: Super Contributor
timestamp: May 05, 2021, 08:46:43 am
content: Quote from: bachtoon on May 05, 2021, 08:38:44 amIf you're sure that these are the valid parameters, is OK, but nobody can tell you if everything will be 100% OK, you have three options: sell the device for parts for someone else to concern with, try to repair it as described above and if the EEPROM is bad, replace it and deal with the realignment and re-setting the important parameters, or replace the panel and just deal with the realignment.Also, just a head-up, when I've received my new panel I did a factory reset at startup (if the MCU finds the memory empty, with reinitialize anyways with the default values, but I've only found this later) and the device was working reasonable OK, I needed to calibrate the voltmeter and the S-meter and that was it for my modest needs.Cheers,DC1MC

author: bachtoon
author_rank: Newbie
timestamp: May 05, 2021, 03:17:34 pm
content: Ok ok, many thanks.

author: bachtoon
author_rank: Newbie
timestamp: May 05, 2021, 03:58:53 pm
content: Message received from yaesu.Hello.Thank you for your answer to my email.If it is just firmware corruption, then re-flashing the eprom may resolve the issue.However, it is something that needs to be done by Yaesu.DC1MC, do you have a solution and method to inject the software please? It's difficult ? Do you have a backup of an 817ND please ?Thank you for your reply.

author: DC1MC
author_rank: Super Contributor
timestamp: May 05, 2021, 04:26:13 pm
content: Here we go again, if you want to keep and repair the device, first do the recommended checks, then replace the EEPROM with a new one, then do the factory default reset and if the memorized values are stable and survive a power-cycle we'll talk about alignment of the device.AGAIN: using device specific parameters from some other device is guaranteed to make your device worse than the factory defaults.

author: msraya
author_rank: Unknown
timestamp: April 14, 2022, 08:19:27 am
content: Finally, I managed to repair my FT-817. Now it is working very well.https://ea7ee.blogspot.com/2022/04/ft-817-repair.htmlThank to DC1MC to give the Italian Service reference!!RegardsManuelEA7EE

author: DC1MC
author_rank: Super Contributor
timestamp: April 14, 2022, 08:31:23 am
content: Quote from: msraya on April 14, 2022, 08:19:27 amHi Manuel, I'm happy that everything worked for you.Cheers and 73 de DC1MC

author: DK1TCP
author_rank: Newbie
timestamp: March 23, 2023, 06:13:44 am
content: About 2 years ago I got a used 817 as a gift. It worked, with some little flaws... On Christmas '22 I decided to change the leftside rotary-encoder (often turned "backwards" or jumped wildely) with an Chinese Part from my QRP-SDX-Project. It worked, but the resolution was bad. So I "recycled" the old encoder and changed it again: perfect - for about 2 months.Then suddenly some strange muting effects occurred, mainly in the receiving stage. It turned out, that the signal going from mainboard to frontpanel-pot and back was temporarily interrupted. Fixed it with resoldering two pins on the 50-pole Connector (front panel). Hard work with degrading eyes...Some weeks later (Jan. '23) it got worse. Muting occured in the TX-path, FM-Volume was not anymore settable, other strange effects took place. After reopening for the 15th time, it seemed that the flat cable was broken. Ordered a new one - happy for some days. Then TX-muting reappeared with the new cable...So I decided to do some measurements. Test-cables from underneath the mainboard to the outside (analog scope HM-205) were soldered, another 20 or 50 times I disassembled the unit and got an idea, that I²C signals going to the mainboard were bad in the state of muting-failure. This was synergy after I got in contact with DC1MC and EA7EE from this board. KA7OEI pages were very helpful to understand what's going on.To make the long story short: after a complete resoldering of the 50-pole connector on the front-panel and reusing the original flatcable (I broke the mainboard-connector at the 51th disassembling-session and had to replace it additionally) things are o.k. now since about two weeks! No EEPROM-change, no data-loss, no MCU-horror.0.5 mm 50-pole was a challenge, but a specialist-soldering-guy in my surrounding did a perfect job. With my eyes I cannot do this anymore...So I have a (momentaryly) perfect working FT-817ND again and want to share this experience with you in DC1MCs thread.Thanks for your patience and vy 73 DK1TCP

author: @rt
author_rank: Super Contributor
timestamp: June 20, 2023, 02:18:22 am
content: Hi Guys 😀 818 owner here, and thankfully no problems yet,but I’d love a copy of the dumped EEPROM, even from an 817nd.I’d like to verify a few things such as if the 60 meter frequencies arestored there, or in program memory.I have also heard that the user’s callsign (for auto keying) is stored inan area of on-chip EEPROM similar to some of the pics, as the callsign cannever be found on the stand alone 8 pin EEPROM.Cheers!

author: Nahim
author_rank: Contributor
timestamp: June 21, 2023, 03:18:39 pm
content: 1. Remove the instrument cover.2.Turn on the device and check the voltage of the power supply.3. Then wait until the transceiver loses gain and at that moment change the transceiver supply voltage again.the device is old and most likely the electrolytes are out of order.This is a simple repair.