A masterclass in fault diagnosis, location and PCB repair! 👍👍 I bought a used 897 a few years back and the first thing I did when I got home was try all the bands/modes etc. The second thing I did was take the lid off and have a good look round to see if anyone had been in there before!
Makes you wonder just what someone was trying to do. Good job on locating the problem and fixing it Peter. I enjoyed watching and thanks for sharing. 73
My guess is they were trying to do the extended tx mod and confused that resistor for a jumper on the opposite side of the processor that gets removed for the mod. Your videos are the best, Peter, I have learned so much from you, and appreciate the time you spend and the detail you go into I would love to see a video detailing the functions, setup, and connections of the R&S communications test set.
I have already had such repair attempts on my desk. After asking the owner, I got told by him that someone has already tried to repair. This repair specialist has soldered a wire to the supply positive pole and then tried to reactivate all the connections of the µC with the other end. "Devibrilator method" .... incredible thoughts go around in the head of some people ..... Well done Peter! 73 and a nice weekend
Yeah that is very often the story you hear afterwards. Some times the owner even don't know about the mess the other person did to the radio.. Thanks for comment Bernd! 73
Great video. I succeeded to repair my 897, with the same symptoms as in your video. I replaced the EEPROM, but without any change. I remade the soldering at the processors pins and now it's working perfectly again (pin no. 21 and 23). Thank you sharing your experience. 73
LOL, worst part of working on so many different makes and models of radios is we never have them on the bench long enough to learn how all the features and functions. Just turning on a radio and selecting a frequency and mode can be a challenge without the operating manual with some of the newer radios. Really have to wonder what the heck someone was doing to that poor chip. Looks like a miniature beaver was chewing on it. Luckily it just needed to be reflowed and a new resistor.
What am mess! Flux-free solder attempt with a banggood 3USD iron... SMT is no plumber playground! You did a good job Peter, and still quite calm! As i dont like coffee, i had to drink some real strong black tea cups and some spheric music in the background to rework that thing... Respect!
Another great repair Peter, I just love clearing up after have a go heroes. Everyone thought that the advent of SMD technology would stop amateurs playing, sadly from what I see it seems to have had the opposite effect. Keep up the good work.
How lucky are the OM who live in your area, i am envious :) Thanks for sharing Peter this professional video. Wish all tech guys were like you ! 73, Chris
You are a really lucky man. As far as I know that EEPROM holds not only the memories and user setup, but also a callibration data, which is why radio does not work (or look like deaf) when the EEPROM is failing in some way. If something destroys that chip (or for some reason this chip becomes a little bit sclerotic), you have to go through the whole factory alignment procedure when this chip is replaced. So you are really lucky you do not have to go through this long and terrible procedure. The missing resistor is pull-up resistor for one of the line between the MPU and memory. That pins are open-collector type, so they have to be pulled up by some resistor, that's why the MPU was not able to communicate with that EEPROM.
For the newbies it might be interesting, why this missing resistor screwed the hole radio up? SDA and SCL are the two lines that connect the EEPROM to the CPU. This is a so called IIC or I²C bus it is multi-master capable. So multiple chips on that lines may talk to each other (one by one). To avoid shorts caused by one chip pulling a line high while another chip tries to pull the same line low, the line is pulled high by a resistor, while all chips are only allowed to pull the line to ground. If this resistor is now missing, the line is floating around and all chips listening are just reading mostly illegal levels. Btw. this is a common fault even in TV or audio equipment, that a broken resistor or a dead chip shorting one IIC bus line is causing a whole device to fail completely.
To be honest YT algorithm has led me to you fixing other "shops" repairs, and it's quite depressing, really. On the other hand that's how I managed to get my hands on a nice transceiver recently, so I should be grateful maybe :)
Wow indeed my friend, it seems whoever attempted the repair before you did not know that a hammer & chisel was not the correct tools for this job 😁 Another great repair here Peter. Cheers friend, John.
You zeroed in on that fault very quickly, one might even say that you had super human deducing abilities, I guess we need to get you a cape and a T-shirt with a big 'S' on it. As always great job and thanks for sharing.
Hallo Peter, vielen Dank einmal mehr, für Deine große Mühe und Deine Expertise !! Einmalmehr ein sehr gutes und aufschlußreiches Reperaturvideo von dir !!! Ich sehe diese Videos mit großem Interesse immer wieder gerne !! Hab eine schöne Zeit, bis Bald mal wieder vy 73 es 55 de Ralph DB 9 FQ C 31 KM
Good Morning Peter, Yes I did enjoy the presentation and your fantastic video on the radio. The parts are so small for that 47k resistor and you're good understand how to place the part in their correct orientation, all by reading the schematic. 73 de Dennis
Peter another fine mess you have to sort out it looks obvious somebody didn't seem to know what they were doing some people should leave repair work to engineer like yourself another success peter :)
Danke Peter, I enjoy learning from you and another site from Louis Rossman in the process of reading schematics to repair electronics. The process is very helpful for my future repairs on my bench. Sehr gutes. Grusse von Houston Texas. J K
Nice fix Peter and well spotted as always. I have no idea why someone would mess there. Maybe they were trying to do a wide band mod and removed the wrong resistor. Great job
Good job Peter. It looked like a skitzing speed freak was scratching on the pins. He just needed to scratch them in the correct sequence...lol I wouldn't trust that EEPROM.
As I told you before, publish your Paypal acct & you will get a lot of donations. I & others would be glad to throw a few euro your way to pay you back for all the good you do.
Simple and successful repair (and inexpensive for that lucky owner). But I'm wondering, what have they tried to do on that EEPROM ???. Brute people.. xD When removing a faulty used transceiver housing covers you never know what kind of surprises and brutalities await you. xD
Hi Peter ,looks like the golden screwdriver operators are still about, I suppose they are keeping you busy , another fine repair even by you though it was a shocking discovery. 73 Paul M0BSW
I wonder whether the person who "repaired" that radio had originally put 2 pull-ups in there, but one had a couple of cold solder joints and just popped off? There might be an 0403 resistor floating around in that case somewhere. lol
MTQMB is your quick memory bank which it should not be on unless you require it for quick memory use MT is when it has been moved from the quick memory bank on the via phone off but still holding approximately the same frequency do you need to press V/M and use the VFO and then see if all of these memories and the use of the radio functions personally I would give it a full reset and then play with this. Regards Jeff
I'm think someone had the cover off and dropped something onto the board. That caused the damage and the resistor to come off. Then of course that person never found said damage (or made a botched attempt at a repair).
Makes me wonder why people that bring a radio to you try to hide information. Makes your job much harder than if they would just tell you exactly what happened and what someone tried to do.
Great work,what ever some hacker does you always fix it,, thanks for video, hope to see you again. looks like your dressed warm cold in shop ? have a great day Peter
Ok I have the same startup symptoms. I replaced the EEPROM, but no difference, I am tempted to replace it again. Did you have any suggestions? I would send the radio to you, but the freight will be high. Many thanks.
There sure are some " Butchers " about Peter when it comes to repair work , That was awful soldering , People who mess up a nice radio like this because they are awfull solderers should be banned from owning a soldering iron 😁 , You were very lucky indeed in that it wasn't any worse , Very lucky indeed Peter 👍
HI there, thanks for the great video. Which flux were you using? I'm using liquid but that gel stuff looks great. Do you need to do a rinse after use? Keep up the great videos.
Working with reword for over a decade myself, Isopropanol Alcohol (IPA >70%) works great as a solvent - and Kimwipes (lint free technical wipes) to wipe off the crud. Let the flux cool and harden, and it'll chip off in large chunks with a sharp dental pick, spot IPA applications and Kimwipes will clear what's left. Easier to do under a microscope than with old aging eyes (ask me how I know). Also much easier to do soldering if you get a half decent solder station - I'm used to being spoiled at work so I only use Metcal or JBC ESD-safe SMT rework systems (I have both, each serves a purpose).
WOW, I once saw a guy who added a ton of solder with a big slater's soldering iron and almost melted the processor on a brand new FT-1000 as he wanted to "make the solder go deeper inside the board to get the CB band on" (don't ask me why please! ^^).
My FT-897 all of a sudden has No Transmit. I've tried different mics, disconnected all external devices etc. No Red LED Transmit at All. Everything else works fine. Would this be the problem?
I wonder if these messed-up radios get 'laundered' (sold-on and bought) before they're sent in for repair. Based on what Peter is saying, it seems that his customers generally have no idea what's going on inside their radio (i.e. as if they didn't do it). Otherwise wouldn't they confess their sins to help get their valuable radio fixed more efficiently? I hesitate to assume that Peter's customers are not being honest with him, so cases like this must be from the used equipment marketplace. Maybe. Sometimes. Perhaps. Speculation.
I have this, my radio is facing start up problem, not getting start, relay sound is audible, screen light is illuminated slightly, please suggest, what I should do, VU3SQY, #Ascertain
I'm pretty sure everybody is thinking the same as me. What the hell?! There seems to be no reason for someone to be messing around with the eeprom. A simple fix in the end at least.
bei meinem FT 897 macht das Display Probleme ... Ich habe drei bis vier vertikale Streifen im Display ... Leider ist das Display und auch das Panelunit als Ersatzteil nicht mehr erhältlich ... 73 de DL6RDE, Charlie
ja das ist ein bekanntes Problem. Manchmal hilft es die Anschlüsse nachzulöten, jedoch ist das eine 50/50 Sache, denn wenn das schief geht ist das Gerät verloren...
@@TRXLab besten Dank für den Tipp ... das Panelunit ist in DL wieder als Ersatzteil erhältlich ... Preis knappe 185 Euro ... Ich versuche zunächst mal die Anschlüsse nachzulöten ... vielleicht habe ich ja Erfolg ... ansonsten bin ich jedem Deiner Videos dabei ... herzlichen Dank für Deine Arbeit !!! 73 de DL6RDE, Charlie
sei vorsichtig das geht nicht mit einen normalen Lötkolben! Heißluft vordichtig dosiert das dir die Isolierung nicht schmilzt. Das ist eine Gratwanderung!
@@TRXLab oh je ... Heißluft habe ich leider keine... Ich hoffe, dass der Displayfehler bei den aktuell erhältlichen Panelunits nicht mehr auftritt. Der Wechsel des kompletten Panelunits wäre vermutlich am Besten ... herzliche 73 de DL6RDE, Charlie
Looks like the person who last worked on it tried to solder in the cmos and just bumped the resistor and it stuck to the iron and was lost without even being noticed. Ask me how I know this can happen. :/