Great video! I have an Icom 703 that won't power up and was trying to figure out a troubleshooting procedure. You just explained it to me! I'm new to radio repair so this was very helpful. Thanks again Peter.
I think you made the right decision in the end Peter. Even after fixing the original board more problems could show up down the road at a later time. Specially since this was a brand new unit. You did do some awesome troubleshooting there, Thanks foe another great video Peter. 73
Hi Peter. We are ok my friend. Just so much work here to do. Today I decided to just come out to the shop and do some clean up. It is in a mess from moving stuff around due to heavy water leak in front room. Thanks for asking. 73
Thank you for a great video ! It made me check the specs. in the Icom IC-7100 Service Manual. It states the voltage is 13.8 Vdc +/- 15% e.g. 11.73 ~ 15.87 Vdc. As I intend to use an IC-7100 abord our little boat and use the 12 Vdc net, I measured the voltage there as well: when on shore-charge the maximum voltage (during wintertime) is 14.8 Vdc so no problem there, at anchor the voltage drops to a minimum of 12.2 Vdc before the generator kicks in to 14.3 Vdc so no problem there as well. Not a bad idea to measure the max. and min. voltages of say, your car or mobile home AND checking the specs. of your $$$ set before installing it, only to see it go up in smoke.
Sad to say I have been down that same road. Back in February my 50A linear supply suffered a series pass transistor fault that fed my radios nearly 24V instead of 13.8V. Unfortunately the crowbar circuit did not last quite long enough to blow he fuse either, so the radios saw the full rail voltage. Thankfully no major damage was done and most of the damage to the radios was confined to the TVSS diodes which ultimately took out the fuses after sacrificing themselves. For the initial power on test afterwards and after servicing I like to use my variable bench supply to control any fault current by dialing in a maximum amperage just above the normal expected idle/receive current for the radio combined with a reduced input voltage if 12V. That way if there is a terrible fault very little additional damage will be done. For the transmit test I do the same by increasing the current limit to an appropriate minimum level and then try transmitting, first at low power, then higher, to see if the piper amplifier stage suffered any faults. Then measure all your voltage rails to look for low or high rails while safely powered on. Thankfully, I lucked out since most of the more sensitive radio circuits were protected by inline linear regulators which safely limited the let-through voltage to the more sensitive lower voltage rails and allowed the TVSS diodes and fuses the necessary time to do their jobs and sacrifice themselves. To find the source of any shorted components, like the TVSS diode, regulators, ICs, etc, use a good multimeter with 4-wire Kelvin probes to measure the resistance across the voltage rails at various points, the areas of minimal resistance are either the faulted shorted components or is electrically very near the affected component. This allows you to track down the shorted component(s) without leaving the device powered on for an extended amount of time during fault finding.
I have done exactly the same with my FT-817ND... Forget to change from 28V which I have use previously to 13.8 when connecting Yaesu. Fortunately for me the only damages were the electrolytic capacitor (which exploded) and fuse at the very beginning of the circuit. More lucky then clever. Great video(s), I really enjoy watching for months. Huge knowledge sharing - thank you !
That reminds me of a unit that has been hit by lightning. It may only need a fuse to get it going but soon after that weird things start happening. I knew that board was damaged further than you thought. You were being optimistic with the board but when the next component up the line failed you knew it was a losing battle. Good video and glad you got a new board. You can put a seal of approval on the radio and not worry about a call back to soon. Thank you for the video.
wow, the patience of a saint to go through all of that, halfway through the video I thought "I'd just buy a new board" absolutely brilliant and a spot on decision
Better late than never. I just came across this video, even though I have been scribed for some time. I too was using an external Liner type power supply. It was equipped with over/under voltage and current protection. However, the reaction time of my older supply apparently was not fast enough to overcome the problem to save my radio. The 24 VDC was directly applied to my ICOM 718 's 12 volt input supply. The result was it got toasted! and became a parts box. The good news is this was not connected to one of my newer more expensive Icom radios. There comes a point where you need to make a decision. How far do you go in investing time and money changing out components, or how much do you invest in new circuit boards before writing the radio off completely. A belated thank you for making a posting this video.
Changing the main-board was the best option my friend.. You can never be sure what has suffered in an over voltage event such as this. At least now the customer knows his radio is as good as new again now. Regards John
Yes Peter, I too feel that you made the best decision to replace the whole board !! With a severe overvoltage like that, that voltage spike can destroy a large number of components unfortunately !! I feel bad for the owner too, but hopefully he will bea little more careful and thoughtful now too. !! good job on your part!! and good video!! John Bellas KC2UVN
I agree, sometimes its the only and better way to replace the whole mainboard. I hope a voltage overkill will never happen in my shack...Nice work and thank you very much for your very learnfull video presentation! 73 Ernest PA3DLP
A good call on replacing the entire PCBA. Component level repair not cost effective if there are multiple failures and possibly other components that were stressed
Even though disheartning, sometimes complete replacement is the only logical answer. I'm sure the added cost is hard to deal with, but then again, it is not a total loss.
That would be the sum of all fears. I hope that never happens to me. My Yaesu 991a cost me a bundle; they've gone up since 2017. I cannot imagine frying my radio before even keying it up for the 1st time. Cheers & 73 from W Rusty Lane K9POW in eastern Tennessee
Hi Peter, The 24V will have a cascade effect on all those IC's not rated for that voltage. I hope the radio came up to spec when you finished your testing. WB3BJU
Dennis Fitz It is actually quite easy to do with hot air or infrared, so much so that I would often much rather desolder an SMD board than a through hole board, especially if one lacks a vacuum desoldering gun for through hole rework (thankfully I have such, but many do not). SMD rework can be nice since you do not necessarily need to pull a board in order to replace a component so long as you have good access to the component from the top side since there are no underside leads to deal with. While you do need a slightly different set of tools to efficiently rework SMD boards I really wish that both old timers and newcomers alike would come to realize that it is only a different way of doing things, not a more difficult way of doing things. I see so many who are convinced that fixing and building SMD boards is beyond their ability that it borders on upsetting because it really is not difficult, unless you are trying to work with the really minuscule parts, and I wish more would come to realize that they can do such work at home if they choose!
Thanks for the video. My IC7100 is scheduled to arrive day after tomorrow so I'll be sure to avoid using the 24v power supply. I'm surprised that ICOM doesn't protect the input power better - but at least the board protected the fuses from damage. 😊 I also agree with a previous poster that I'd love to see your desoldering/resoldering, but also disassembly of the cases. On the other hand, that was a very long video for the information provided. Just a friendly suggestion here: if you could avoid the use of the syllables "uh" and "ja-" and increase your speaking speed somewhat, I think you could produce the same information in remarkably less time.
I have noticed that everything that had been built since 1998 has less and less protection on power lines. And there are two reasons - It is cheaper and over-voltage\polarity-reverse is not being covered by the device warranty. Why does this happen? Because manufacturer cares about sales and reducing the support costs. Buy, burn it down, buy more and more!
You should limit the supply current, so you won't damage the PCB when a component blows up. I would replace any components that exceeded their maximum ratings, before even connecting the power back after replacing the first chip inductor. Probably, the regulator and the DC-DC converters took a hit from the 24V supply. Having said that, good repair.
I don't know if you charge by the hour but I think you made the right call on this one. At some point the time involved would rack up a bill that would buy a new radio.
Great work, I can empathize with the owner. Puting too much voltage in the supply could cause heartache. It is a shame that you have to toss the original board after all of that troubleshooting.
I love these videos. Additional benefit is I get to pick up a bit of German from the instruments at the back!! Spannung == Voltage! Great work. Question though - what is your thought on why the manufacturer doesn't put voltage protection on the input? Is it just a cost thing for them (as a commenter pointed out below) or is their some technical reason.
Thank you, glad that you liked it. Well regarding your question. I don't think that is a technical reson as it is no rocket science....I truly believe it is always cost reasons...73
Nice troubleshooting. Shame on iCOM for not using a crowbar on the input. I think I would have gone with the original board and just repaired it if and when it failed.
They probably have one in their power supply - there has got to be some reason it costs $400 lmao. I love my IC2300H, but not enough to give it the icom SMPS lol
Have you heard of anyone who plugged an external speaker plug into the remote jack instead of the external speaker jack and now the tune button will no longer tune the external tuner on the IC-7100 ?
In my days as a trainee radio/TV tech (47years ago), before any measurements were made, the three senses were used. Look over the board, smell, then heat check with a finger etc. Still holds true today.. GI0OTC
ijust came across this vid during my search for an IC-R7100. Both fascinating and depressing! All that money.....and the owner doesn't check the proper voltage! Very sad.
I have a Yeasu FT-8900R which burns fuse when power is connected. This Radio was in my car and without eny use for few years, since my car had a serious main brakecylinder problem before we found what was wrong. My question is that could it be, forexample, dryed electrolytic capacitor in main voltage which causes short cut..? Certainly it´s not transmit unit because it´s not been used for meny years. I would be very greatful for eny information..
Another great repair video Peter. If you don't mind me asking a dumb question is 24 volts a standard voltage where you are? In the US about the only place you see higher voltages is the military and aviation. Just wondering how the owner accidentally hooked up to 24 volts. Mike
MikesRadioRepair Even here in the U.S. there are some higher powered HF radios and lower powered external amplifiers (say, 400-600W) that use a 24 to 28V, even 48/50V, external supply for their power amplifiers (the rest of the radio is often still operated from a 13.8V rail). The higher voltage both increases the linear range of the power transistors in the PA while also reducing the need for ultra-low impedances in the PA stage, and power delivery, to achieve the higher power output (consider how little impedance must exist to deliver 40-100 amps into a PA circuit, not just within the PA but also the wiring between the PA and power supply/battery) -- doubling the source voltage simplifies the design and power delivery versus 12-13.8V and allows for more reasonable wire gauges.
Excellent video as always Peter. I always learn something from listening to your methodical approach to troubleshooting and this video is no different. Great job. Out of curiosity, what was the cost of that replacement board?? That radio retails for nearly $1000 here in the US. 73 de N0BPS
TRX Bench Ouch! That is a lot of pain for a few seconds, and a very human, act of momentary carelessness! My heart really goes out to him as I have had to repair my radios as well after a power supply fault allowed the unregulated rail (about 20-24V) through to my radios. No matter how many electronics I have repaired over the years, my heart still sinks whenever I see that magic smoke (they really ought to sell refills of magic smoke). This case is a good argument for using Powerpole connectors with different keying for your 12V and 24/28V power supplies so that they may never be attached to the wrong supply. I use them extensively for my gear as they really go a long ways to reducing accidents when connecting and disconnecting equipment (especially the dreaded polarity reversal). We all make dumb mistakes every now and then no matter how careful our personality.
Hi Peter, as always great video, even if have not been able to fix it by changing some little components (it's the 1st video of this kind isn't it?) But if it is toasted too much, even the "wizard" has no chance ;) 73's
LOL yeah that' it. Well to be serios you always have to have the costs for the om in view so there is a Point wehre you have to Go another way. Personals I would Love to See what the Problem was. 73
What was the cost of a new board? Always discuss the costs of parts (when they are expensive) so we can learn economics of your decision to get the board rather than continuing diagnosis. What if there were further problems (on other boards)? What would you do then?
Hi Peter, what kind of equipment and or trick are you using when removing components like the surface mounted dc-dc chip. Do you use a hot air soldering iron? , maybe you could make a video about this, when working in a close enviroment to ather components like the caps and coils around the chip. As always very good video, thank you for making them.
christopherkise Hot air and/or infrared are generally the best options for reworking surface mount boards, especially if you wish to avoid damaging the original component during removal (such as when removing components to isolate issues during troubleshooting), allowing for reuse of undamaged components when finished troubleshooting. You can also solder in the replacement components with hot air or infrared, though many components types may also be soldered using an ordinary soldering iron when required. Sometimes you may also need a large infrared preheater to actively preheat a board during rework if the circuit board contains large copper fills or ground planes that wick heat away to quickly to allow safe rework with only direct local heating (you would be surprised how much heat a copper ground plane can wick away!). In such cases, you would preheat the backside of the circuit board to a safe intermediate temperature (such as 100C) to reduce the amount of localized heat you will need to apply in order to solder or desolder a component -- lead free solders generally need to achieve at least 220C before liquefying, so heating the opposite side of the board to ~100C makes it easier to overcome the copper fill or ground plane so that you can achieve 220+C.
I put Kapton tape over caps and stuff around the IC that I'm removing with my Hot-Air Rework Station to help keep them from coming loose and blowing around. I also learned to use the lowest temp setting that will melt the solder.
I would like to know your opinion on those inexpensive Chinese radios in terms of ease of service, ease of getting replacement parts, [clarity of instructions etc...
Well Thomas you already pointed out all the problems why it does not make sense to buy a Chinese radio at the moment..May be the situation will change in the future but for now NO 73
Hi my real time clock battery backup on my IC7100 is not holding much charge anymore as it dies after a few days switched off. I was trying to see how easy it would be to swop and wanted to know is it soldered into place? I think it's near to the SD card slot. any chance you could have a quick look on the broken pcb and let me know. Thanks!
really discouraged with icom. i literally order approx $22,000 a year in gear with the icom name on it ... i order from gigaparts which is excellent... one time i have a problem and icom will not stand behind it .. i order 2 icom 718 radios at a time, one time recently i get a case that is dented, " not the box the case" so i know it happened at icom , i do not blame it on gigaparts, there is no way it happened at gigaparts, it happened at the factory . was told i had to purchase a new case lid for $36.00 .. nice staff at icom but when it comes to customer service i am really truly disappointed. over not making it right they are willing to lose a customer that spends so much money on their product. .amazing......Attn icom. This will be posted in every area of the web i can find to copy and paste..
This customer took responsibility for their mistake and paid for the repair. Didn't complain to iCOM and threaten to lose their business unless they gave him something he didn't deserve. I'm going to buy an IC-7300 this year, and if god-forbid I dent the case, I'm going to pay the $36.00 for a new lid.
I had the same with Icom-UK. They are a waste of time. Brand new IC-9700 and an inductor went open after one week from new. It took my supplier to back me up before they would act under warranty. Icom tried to say it was my PSU that was not an Icom PSU (It is an Icom PSU), but I was mobile at the time running a straight 12V. They had no option but to fix it.
I own a Icom 7300 and it was *UNHOOKED from the power supply* . I was going to move the radio to another location and when I picked it up, the power supply leads touched together and I heard a loud snap! It was like there was stored voltage in the radio. When I went to hook it back up again, it wouldn't turn on. I checked the circuit fuse on the board and it was O.K. and the other fuses are all good. What do you think it could be? It still draws a little power when connected, though. Probably the power amp section drawing the power.
Thanks for the reply. I enjoy your videos! Well, at least I know better now to always keep the power cable completely disconnected when in storage. There's three caps right next to the circuit fuse where the power leads connect to the board and there's a 9v regulator right after it. My guess is that the caps were still charged quite a bit and by shorting the power leads, it damaged the regulators and possibly the caps too. So, I'm going to pick up a hot air rework station and order the parts that Icom was so nice to list for me on their online service manual!
Hi Peter, i wonder if you had found this defect quicker with the thermal Camera. Just replacing the 2nd Coil and slowly bring up the Voltage until you see the shorted part. 73 de DK3JF Jörg
Stupid disign, In older vhf (Marine) radio,s a zener diode is placed over the suplly, behind a fuse.. Higher then the zener voltage the fuse will blow, and the zener, But the rest of the boards wil be fine (Forinstance Sailor RT 144, and the Sailor RT2048 marine radio,s have this..) Saves a lot of damage! Hopfully the processor is still fine, and dident get any overvoltage...
