I am sure this has been covered hundreds of times but maybe there is a new solution. Displays A4 and A5 are out. The connector has the correct signal on it compared to the other displays but the digits are out on those two. This is my only radio in my basic VFR Cherokee 140B. Other than missing those 2 seven segment displays it functions properly. I am just looking for a low cost legal way to get the display functioning again. I am capable of installing an LED display but my understanding is they are not legal for TSO radios and I do not have the credentials to legally do the work. I know the KX200 is a drop in replacement which is about a $6,000 investment, a lot for replacing a working KX155 with just a bad display. I don’t use the VOR section and was considering just replacing the KX155 with a SW Avionics V6 comm only radio for $1,500 but don’t know the cost to rewire the panel which may be as much as buying the KX200. Also is it legal to not have VOR working in the airplane since it is there? Any solutions would be helpful. Thanks
King kx155 display issues
- Thread starter RonP
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The ICOM A220 with MB-53 adapter uses the same 30pin edge card connector as the KX155 but the pinouts are different. But re-pinning the connector could be cheaper than re-wiring the panel. You'll also have to decide whether you actually like the ICOM A220 rather than merely shopping on price.
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You could get in line here: https://www.kx-155.com/
I've these folks repair 155s too: https://www.pacificcoastavionics.com/
Some hints here on a DIY LED replacement. Dionics seems to have abandoned it's online presence, but Dionic parts are still available from suppliers.
I've these folks repair 155s too: https://www.pacificcoastavionics.com/
Some hints here on a DIY LED replacement. Dionics seems to have abandoned it's online presence, but Dionic parts are still available from suppliers.
deyoung
Line Up and Wait
I don't know how difficult a display transplant is to do, but I actually have two KX-155s, both dead somewhere in the audio sections but (last time I powered them up anyway) the displays were both fine. I don't know if that's a reasonable way to go or not...
pfarber
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Most likely the display is fine but the driver is bad. You'll need either an o-scope or a logic probe to determine the real cause.
I would think a -155 isn't gonna have SMCs so taking chips out and swapping them should be easy.
USB O-scope's are cheap and good to about 20Mhz or a little faster depending on your leads. A decent hot air / solder station is about $75 and worth it if you get digital temp control.
I don't know if opening the case is legal in certified land... but in E/AB world its not an issue. After your repair send it out to get tuned and see if they flag it / refuse to yellow tag it.
I would think a -155 isn't gonna have SMCs so taking chips out and swapping them should be easy.
USB O-scope's are cheap and good to about 20Mhz or a little faster depending on your leads. A decent hot air / solder station is about $75 and worth it if you get digital temp control.
I don't know if opening the case is legal in certified land... but in E/AB world its not an issue. After your repair send it out to get tuned and see if they flag it / refuse to yellow tag it.
Nothing illegal about it. However, a mechanic can't work on or repair the transmitter portion without the correct FCC license.
I am an electrical engineer and I know my way around a schematic and an oscilloscope. The signal that drives displays A4 and A5 are present on the connector and the display contact. This points to a display issue since the signals are good. I am trying to assess what the issue is before sending it somewhere(?) for a proper repair.
Deyoung, if you think you have a good display on the 2 dead units would you be interested in selling a working display?
Deyoung, if you think you have a good display on the 2 dead units would you be interested in selling a working display?
deyoung
Line Up and Wait
I expect - I don't think I'm going to have them repaired so they aren't doing me any good.
deyoung
Line Up and Wait
What do you think is reasonable, and where would I be shipping it to? I will ship the entire unit rather than take a chance on breaking the display taking it off. Sold as is, but (the display) worked when it was powered on last. For one radio that was a few days ago, for the other probably a year-ish.
I was thinking $410 would be reasonable. On EBay there is just a display for sale for $370. The seller states “tested good” but I can see solder on the gold contacts. That concerns me. There is also a complete KX155 parts radio for $450 in unknown condition. My offer of $410 is the average of the two prices. I understand the radio you are offering is “as is” but my interest is a working display. Preferably the display that worked a few days ago will still work and buy me some time until I save up to replace the KX155. I live in New Jersey in a town even most people in New Jersey never heard of, a small borough called Newfield. Best I can describe for those not familiar with New Jersey is it is about an hour north west from Atlantic City.
traumamed
Pre-takeoff checklist
If you hold up a flashlight/phone light to the bottom-left-ish area of the display, do the numbers illuminate? If so, then there is an easy and basically free fix, although it doesn't necessarily fit your definition of being strictly "FAA authorized" if you don't possess the credentials to do it.
Traumamed, are you referring to the dimmer photocell? All the displays are working and are bright and do dim EXCEPT for A4 and A5, they do not illuminate at all. The signal on the connector is correct and on the display contact for A4 and A5. If you have a solution, legal or otherwise, I would be curious how to get displays A4 and A5 to illuminate like the rest of them. Sure would be a big help. Member Deyoung may hook me up with 2 KX155s that are not functional and have working displays. Regardless, from an engineering perspective would love to know an easy fix to get 2 displays, A4 and A5 working again. I am anxiously waiting for the secret sauce. Thanks
traumamed
Pre-takeoff checklist
Yes, the dimmer photocell, which it sounds like may not be the problem for your unit. Weirdly though, there are examples of people having KX155s that only have a couple of digits going dark but it still ends up being the photocell, with the digits re-illuminating under exposure of the photocell to bright light. It's an easy and inexpensive fix for the hangar fairies to DIY.
If it is your screen, there are these guys as well as another option to the ones you already have available to you. Unfortunately, as with everything aviation, the prices have gone insane. Their OLED replacement screens are now up to $788. For a $20 piece of OLED glass. They were $595 not all that long ago. They work well, though.
EDITED TO ADD: The link I posted is *not* an endorsement of this guy and his sketchy web site. I know a couple of people who bought his screens and they did arrive and they did work. Even so, I am by no means saying this is the right solution for you or anyone else. My personal ethics are that solutions like this are acceptable and can be done within the scope of FAA legality as VHF radios are not required to be TSO for Part 91 ops, and there are things like FAA AC 23-27. I'm sure someone will be along shortly to disagree, and that's fine. We are talking about the screen on a radio that was developed in the 1960s and has been out of production for over 20 years. My position is that no one should be paying four figures to keep these relics going. But this is my opinion and mine alone. /disclaimer
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Traumamed, I did try a bright single beam light directly into the photocell and A4 and A5 are still out. The link you sent I have looked at before and it is quite scary what the owner posts there threatening customers. As of tonight the following is posted on the CONTACT section:
“We are “Closed” concerning answering emails; to catch-up on several orders, & especially Señor Lachmann’s DME!–>Fully Repaired and Returned (1-year later)!”
The website also states:
“CAUTION, Rant ‘N Rage: “We” means I, Me & Myself. It means that “we” do EVERYTHING myself; including answering stoopyd questions already posted; such as, PRICE! To the idiots that break LAWS on Social Media (e.g. Character Assassination: ILLEGAL!!!<—LawSuit Potential).”
This guy scares me to do business with. He also states the OLED upgrade only requires a logbook entry however I have read it is only valid for experimental aircraft. Technical stuff I know, fine points of the regulations I don’t know that well.
Thanks again for the advice.
“We are “Closed” concerning answering emails; to catch-up on several orders, & especially Señor Lachmann’s DME!–>Fully Repaired and Returned (1-year later)!”
The website also states:
“CAUTION, Rant ‘N Rage: “We” means I, Me & Myself. It means that “we” do EVERYTHING myself; including answering stoopyd questions already posted; such as, PRICE! To the idiots that break LAWS on Social Media (e.g. Character Assassination: ILLEGAL!!!<—LawSuit Potential).”
This guy scares me to do business with. He also states the OLED upgrade only requires a logbook entry however I have read it is only valid for experimental aircraft. Technical stuff I know, fine points of the regulations I don’t know that well.
Thanks again for the advice.
No thats correct, logbook only even for TC aircraft. Now whether a mechanic wants to sign it is something else. I've only used Ed Soldan at kx-155.com so have no experience with the display guys.
unsafervguy
En-Route
last time i talked to ed, that was a couple of years ago, he was talking about shutting down the 155 repair business. so, if you are in need of repairs give him a call first and find out if he is still repairing them. just as a note, ed is a master at 155's.
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At what point do you determine that it's a better option to buy a new unit, or even a used Garmin something? Not being snarky - this is a legimate question for any avionics for any owner. As a plane owner, I have to deal with this as well. Advice and POV's always welcome on how folks approach the question of repair or replace Avionics.
If your XYZ broke on your current radio, and it is that old, what is the chance of something else breaking on it? At what point are you spending money fixing something that isn't going to provide the reliabilty and performance you want, while instead that money could have contributed to a different unit? That new unit would be stable for years to come; you'd not be paying in money and time to fix it?
Case in point. My ELT battery needed replacing. ELT works, but the model is so old finding a suitable battery was pulling teeth and stupid expensive. In 2 years I'll be replacing a working ELT because a new ELT with it's battery will cost just a bit more than just the old ELT's battery, and in the future battery replacement will be doable and a lot less expensive.
If your XYZ broke on your current radio, and it is that old, what is the chance of something else breaking on it? At what point are you spending money fixing something that isn't going to provide the reliabilty and performance you want, while instead that money could have contributed to a different unit? That new unit would be stable for years to come; you'd not be paying in money and time to fix it?
Case in point. My ELT battery needed replacing. ELT works, but the model is so old finding a suitable battery was pulling teeth and stupid expensive. In 2 years I'll be replacing a working ELT because a new ELT with it's battery will cost just a bit more than just the old ELT's battery, and in the future battery replacement will be doable and a lot less expensive.
Kiddo's Driver
Pattern Altitude
He was still doing them back in May.
455 Bravo Uniform
Final Approach
I think it’s a personal decision, based on finances, thriftiness, and missions.
I recently replaced a KX155 with one that I bought from a POA member. I could have chosen to buy new, but I’d be grounded for rewiring the stack and didn’t want to spare the time. Plus I gambled on getting a few years out of the replacement unit.
Unfortunately, there is no one answer due to the variances in everyone's situation. But when asked, this is the basic recommendations I would give:
1) How long do you plan to keep the aircraft?
2) Is the item in question required to fly the aircraft or is something that may only limit its use?
3) What are the top 3 actual issues with item concerning repair or replacement? I found this takes some research as rumor or anecdotal comments tend not to be the actual truth.
So when an owner had the answers to those questions, they were able to make the best decisions for their specific situation.
traumamed
Pre-takeoff checklist
1. Obsolescence.
2. Financial feasibility. That doesn't mean, "can I afford something new/modern?" It means that there comes a point, whether due to obsolescence (think KX-155) or to damage (think totaled car) at which it is more financially efficient to replace the product than repair it.
it's totally fine to run an obsolete item to the point of failure if it is still serving its purpose. If it can be repaired for a trivial cost, then it might even make sense to fix it.
The costs being cited by some in this thread include a comma. That is not trivial for the (obsolete) component in question.
455 Bravo Uniform
Final Approach
Indeed!
It's just real hard to replace a radio that does everything you want and nothing else with a $5,000 unit that doesn't add any functionality. I really like my kx-155, much more than the newer garmin units I've used. I managed to solder a couple broken traces on my display to limp it along a little longer. Now the nav side has stopped working, but I'm pretty sure I just need to take it out and clean the back connectors again.
It hit a great intersection of advancing technology and declining repairability.
Kiddo's Driver
Pattern Altitude
There were three major production blocks. You want the middle block. The First block had design flaws, and the last block suffered from the cheapening of the production process.
Kenny Phillips
Final Approach
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I had one installed new in my Skyhawk in 1998. Looking at the website of the flight school that now owns the bird, there's some Garmin goodies, but still a KX155.
How can you tell which one is which?
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Pick the one that works
Kiddo's Driver
Pattern Altitude
I had to go back through my notes. The ones with a silver data plate sticker that says "Made in Singapore" were the good ones.
I am the person that started this thread and I appreciate the replies but there is more to the story regarding the decision point to fix the KX155 or replace it, it is not my airplane. My cousin owns it and lives about 2 1/2 hours from me. He encouraged me to get my license and when I did he flew the Cherokee 140 to my local airport, threw me the keys with 2 requests; (1) you enjoy flying it and (2) you fly me back home. That was 10 years ago. I pay for the tie down at my local airport, insurance (of which I am listed as a pilot), maintenance and annuals except every other one is done at his airport by his A&P/IA. That’s it, no rental fees, no pay to him per hour, basically a free airplane to use. Sounds incredible but it is true. I do not want to spend the estimated $6,000 or so to replace the comm/nav radio and rewire the panel or $5,000 for a drop in replacement for an airplane that is not mine. The upgrade will reap no benefits for me when I sell it because it is not my airplane to sell! When I hang up my wings I just hand the keys back to my cousin. It is a great deal but has its drawbacks when investing in upgrades to the Cherokee. I also would not ask my cousin to fix or spend money to upgrade the radio just because it is his airplane even though he lets me use it for free, just would not seem right to do.
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Wow. There can I don’t a cousin like that!
How do you pay for / handle major expenses, such as engine overhauls, the occasional significant annual, etc.?
How do you pay for / handle major expenses, such as engine overhauls, the occasional significant annual, etc.?
traumamed
Pre-takeoff checklist
I'm the tool guy in my neighborhood. The guys who borrow a greasy, oily tool and bring it back clean and charged up (if it uses a battery) or gassed up (if it takes gas), along with a few extra fasteners or whatever they "were never going to use anyway," have full and free access to my garage. The guys who borrow a clean tool with a full tank of gas and bring it back greasy, empty, and worn/damaged often find that the next time they want to borrow a tool, it is unfortunately unavailable that day.
WDD, we have not had to do an overhaul but there is more to the story. As kids my cousin could never resist a dare. The Cherokee was an abandoned bird sanctuary at my cousin’s airport. One of his buddies dared him to make it flyable again. Since he can’t resist a dare he bought it and he and his EAA buddies did a wings off restoration. Part of that was an engine rebuild. I think the bottom end and crank was good but all the cylinders were replaced. There is only about 450 hours since then so I don’t expect a rebuild for what remains of my flying years. I pay for the annuals but he covers every other one. He likes to work with his guy and I don’t pay anything. I also learned NOT to tell him when things need to be fixed. I handle these through my local A&P. When he finds out I get the lecture I should have brought it to his A&P so I don’t get overcharged. I swear this is all true.
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This story gets more and more interesting. Please feel free to expound!
pfarber
Pattern Altitude
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Can an AnP replace the display? How about the fan? A knob? A button?
So I can solder in a new display as long as I get a RS to 8130 it? Is that realistic?
pfarber
Pattern Altitude
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They why are repair stations a thing? Only for 121/135? They have a specific Radio class that includes "Radio transmitting and/or receiving equipment used in an aircraft to send or receive communications in flight, regardless of carrier frequency or type of modulation used." Not specifically just the transmitter section.
Are there any AnP that actually crack open radios and fix them? replacing an external knob is usually a set screw, but everything else is gonna require soldering. Unless it undocumented who's gonna take that liability? Granted in Pt 91 world I can throw that page away after 1 year... but that's some shady work.
You still haven't answered the question. In the context of this thread, if you, as a mechanic, solder a display into a KX155 why would you need a CRS 8130 when you can sign off the work per Part 43? 135/121 have different rules.
Yes. Where the line is drawn is when it requires work on the transmitter portion, then an FCC license is needed which some mechanics are known to possess. However, if you need to calibrate the transmitter, which is considered a major repair, then you need approved data to do so which is were a CRS could come into the picture. However, there were other options as well such as Soldan Electronics who had neither an A&P or CRS but could legally repair aircraft radios to include transmitter calibration. An A&P simply had to sign the entry in the logbook.