Monday, August 22, 2011

FT-450 Jack Repair

Well, I finally decided to repair the CW jack on my FT-450.

Based on some discussion on the ft450 owners yahoo group mailing list, this is not a totally uncommon problem.  Apparently, Yaesu used some poor quality 3.5mm jacks on this radio, and they are extremely sensitive to the quality of the cable plugged into them.

The issue is that the contacts inside the jacks get easily stuck on any ridges of the plug as it is inserted/removed.  Look at any 3 conductor 3.5mm(1/8th in.) plug such as a pair of headphones and notice the construction of the tip, a ring of insulating plastic, another ring for one conductor, a second ring of plastic, and then barrel of the plug.

Run your fingernail along the plug from tip back towards the barrel.  Do you feel any ridges or bumps as you pass over the conductors and insulators?   What i have found common is that there insulators are where you will find the issue.  The insulators will be a slightly different diameter than the metallic parts of the plug, and you will feel the ridges.

On the cheap jacks that Yaesu used, the contacts inside will get hooked on and caught on any of those little ridges or differences in diameter.  You will then have to use a great deal of force to pull the plug out, and will bend/break the contacts inside the jack.  Eventually, you will find your jack will no longer work or make contact with one or more of the cable conductors.  That is what happened to the CW jack on my FT-450, and so the jack needs to be replaced.  A word of warning.  The headphones jack is the exact same type of jack, as is the speaker out on the back of the radio, so you need to be aware of the same issue for those jacks as well.

The way to ensure that this DOES not happen to you is easy.  Make sure that every 3.5mm plug you put into your radio is as smooth as possible and has no ridges or bumps along its length.  You will be very surprised at the variation in quality that you will find in this regard once you start checking them.  A recommendation that I got from the yaesu mailing list, that I am using myself is to purchase a RadioShack 3.5mm Y-cable, and plug that into the jack first, and then plug whatever cw key, headphones etc, you want into that pigtail.    For whatever reason the plug on the radio shack Y-cable is very smooth and makes an excellent friend to to the FT-450 jacks.  I can't find the product on their website, but its in the store with all the other radio shack extension cables, adapters, etc. Is their cheap black 3.5mm(1/8inch) Y-splitter cable, not the fancy gold colored one or a name brand one, the cheapo radio shack version.

I tried to document what I did as much as possible to share with others who want to undertake this operation on their radio.

As it turns out my warranty expired a few months ago, and since I have already been inside butchering my radio to make a modification for SDR use a while back, I figured instead of sending it back to Yaesu to pay the service charge and shipping to-and-fro for the repair, I would give this repair a go as well in my quest to be more than an 'appliance user' ham.  Barely a year having a new $900 radio, and I have been inside with the soldering iron a dozen times or so, so I guess I am off to a start.


The part number for the replacement jacks from Yaseu is P1091426.  They are only a couple of dollars for a pair of them.  I ordered two so I would have an extra in case I messed up somehow. Or for when the next one fails, *sigh*.  They do seem to be a little different than the original ones, so hopefully they are using a slightly better quality part than the original and will last longer.  Of course, now I know how to baby the FT-450 jacks and that should help make them last longer as well.

First thing on the list is disassembly of the FT-450.  Like I said, I am already an old pro at this from my other mods.  Its actually quite easy to get to the inside of the FT-450.

There are 4 screws on the top cover to remove, and four identical on the bottom as well(don't remove the rubber feet screws).:


Then there are 4 screws to remove on each side:


Now we can slide back the top and bottom covers.  We don't actually need to take the covers off the radio for this work, so I just slid them back a bit from the front to provide access to the panel.


To remove the front panel you have to slide those plastic tabs over the screw holes, there are two tabs on the top and another set of the bottom.



Once you have all 4 plastic tabs from the top and bottom of the front panel clear of the screw holes, you can slide the front panel all the way off the radio:


The front panel is disconnected from the radio by removing that small ribbon cable from the jack on the PCB. But FIRST, make some marks on the cable to make sure you can remember the exact orientation of the cable to put it back together.

I used a sharpie marker to make a mark on the same side of the cable and the plug, then I just have to line them up when putting it back together.



To remove the cable, pull carefully, and it will come out.  Some cables like this have little tabs to pull up on the socket that loosen the cable, but this one does not.  The cable is just held in by friction.



Now we have the front panel free from the radio and move it to a work surface and put the base of the radio out of the way.



Next we start to disassemble the front panel to get full access to both sides of the PCB.  Remove the 4 smaller knobs(shift,dsp,rf,af) as shown above, they are held on only by friction.   The main tuning know is held on by a small set screw.  First you have to remove the rubber grip ring around the tuning knob to get access to the set screw.




The set screw is removed using a small 2-mm (5/64”) allen wrench to loosen this screw.

Once the screw is loosened, you can remove the main tuning knob. Remove the tension spring and plastic washer from the main dial screw and set those parts aside.


Then remove all of the nuts and washers from the four smaller knobs using a 10mm socket.  I used a deep well socket to make it easier.  Set those nuts and washers aside for safe keeping.



Turn the panel over to the back of the PCB.

Remove the screws from the back of the PCB that hold it to the front panel plastic.  Look for the screws with the rings around them like these:



Disconnect the cable that connects the PCB to the main tuning knob. Write down the colors, take a picture like this, or make a sharpie mark like I did for the ribbon cable to help you make sure assembly goes easy.



Now the PCB can be removed from the front panel and put onto a work surface.



We will be replacing the bottom 3.5mm jack(cw) on the panel.  


Luckily we are not talking about any SMT work here, the jack is a simply through-hole mount.  We just have to remove the solder from the posts on the jack to and remove it.  There are 6 through-hold conductors on the jack(yellow highlights), and two plastic tabs(purple) that hold it in.   Using a solder sucker, solder wick etc to get the solder off as best you can.  I also ended up chewing up the jack from the front to get to the leads and snipping them off the jack, and then used the solder suck to clean the holes out.  You can see I pretty much destroyed the old jack with my wire cutters.


After I you get the jack off, make sure the holes and the PCB are as clean as possible.  Notice my destructive work on the jack from the front caused a couple of light scratches on the front of the PCB.   Nothing was really harmed and these ended up being just cosmetic, but there are some traces hidden there under the jack and you should probably try and be more careful than I was.  The PCB is easy to scratch, so be gentle with it, and yours will most likely come out a little neater looking than mine.



So, now that we have the old jack out and the holes clean, we can put the new jack in and solder it into place.  Notice the new jack has black tabs instead of white ones like the old jack.  


After cleaning the PCB with some alcohol to remove the flux residue from the soldering, its an almost good as new.


I connected the ribbon cable to the radio, powered it on and did a quick test of my CW jack and it works!  Repair successful, now its time for reassembly.


The assembly is just the same as doing the disassemble, just in reverse.  One thing I did is when I ordered the replacement 3.5mm jacks from Yaesu,  I also ordered the new FT-450D style replacement dial kit which I will be putting on during re-assembly.   Yaesu Part#s RA082910B(knob) and RA0829300(rubber ring). Click Here for More Info. Here they are side-by-side to see the difference.  


The new tuning knob is much beefier, and heavier, and it protrudes from the radio a bit more making it easier to tune with the larger surface area for the fingers.  To install the new style knob, you leave off the tension spring and the plastic washer and just put the knob all the way on the tuning shaft and tighten the set screw.

Once re-assembly tip is to make sure you use a lint-free micro-fiber cleaning cloth to clean off the clear inside plastic of the panel where the display is, and to wipe off the display panel as well to make sure you do not get any fingerprints, or dust trapped 'permanantly' inside the radio display.


And there you have it.  All back together and ready for action.  Repair successful. Time and money saved, a little more electronics repair experience.


4 comments:

VE3WDM said...

WOW I don't have the FT-450 but have owned many Yaesu HF rigs. This sure was a long and drawn out process but to have it done at the shop would had been a hefty price for sure. Very nice step by step pictures...as they say a picture is worth a thousand words. I am sure it is going help lots who have this problem. Great blog post.

Road_Hog said...

Thank you for this, I have used this twice in the past year. Once to replace a rotary encoder on an early second hand FT-450D and then, on a new unit to put a ground wire from the head unit to the chassis.

It's always helpful to look at the photos and instructions for taking it apart.

2E0TPO

Joseph C. Bartlett said...



Hi there i think you will have your answer here http://www.mbselectronic.com they are the best and cool!

jerome poichotte said...

Hello guys,
I am F5SJF Jérôme. Please give me the prob for change connector. Here, impossible to traffic with keyer. Dash is ok but no dut. The parameters are ok in the menu. And after test, automaticly TX led flashing. It's necessary to return menu for disabled all parameters cw keyer automatiq.
But I read on the web, many probs with connectors. Where is it possible to buy this connectors, because not possible in France. Many thanks and best 73

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