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Garmin SL-40 com radio frequency problem

BigJohn

Well Known Member
Has anyone else seen this? After 3 years of flawless service the SL-40 has developed a problem where setting a new frequency in the standby side is very difficult because the frequency digits left of the decimal point jump around all over the place when the knob is turned. Once a freq is transferred to the active side it holds still.

Called Garmin and they very kindly offered to fix it for a flat fee of $550. :eek: Pretty irritating for what appears to be a minor problem with a radio I still consider to be fairly new.

Any ideas?
 
The flat fee from Garmin will cover EVERYTHING you list as a problem...worn knobs, scratched face plate, stiff extraction screw, inop functions, plus any applicable needed updates, etc.
 
John,
Have you had the top off? Does it use a mechanical switch or an optical switch. If mechanical, DeOxit is worth a try. Compressed air, if optical.
 
I feel your pain

I have a similar problem with a radio. I don't want to mention the manufacturer because I'm in the middle of the repair process. The digits to the right of the decimal point only change one step. I thought it was related to cold temps, but am unsure now because it does it intermittently in the lovely Florida heat.

I noticed the problem with about 30 hours operational time. Unfortunately, because I bought the radio and it sat on the shelf for three years the warranty was up. Lesson learned there.

A representative of the company graciously offered to fix it for half of their usual flat fee. Nonetheless, I really believe it is a manufacturing defect but there is not much I can do about it at this point. There goes most of the savings I achieved by buying the radio early ... again, lesson learned.

Wouldn't it be nice if the manufacturers offered a warranty of three years and 100 hours of use? How hard would it be to clock and record power on time? Not much incentive I suppose when the market has so few players.

Don
 
A friend of mine had this problem and replaced a resistor network on the front board....cost was about $0.75. This resistor network functions as the pullups for the rotary encoder. Without the pullups at the right voltage the encoder doesn't send the right gray code to the MCU when turned, hence the erratic behavior.
 
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Thanks for the repies......

Never heard of the VAL 2000 before - looks interesting but would require re-mounting and re-wiring. Also I don't see a monitor function, quite handy when you only have one radio,

Yeah, I know the flat fee covers everything - but I don't need all that, my radio looks like new and has only 200 hours on it.

Marty, so far I can't get the *&^*%$ thing out of the rack. It appears to be stuck. I suppose I will have to remove the avionics bay cover and go at it from the backside. Then I will take it apart and do a little old fashioned ham radio work on it.

John
 
Never heard of the VAL 2000 before - looks interesting but would require re-mounting and re-wiring. Also I don't see a monitor function, quite handy when you only have one radio,

Yeah, I know the flat fee covers everything - but I don't need all that, my radio looks like new and has only 200 hours on it.

Marty, so far I can't get the *&^*%$ thing out of the rack. It appears to be stuck. I suppose I will have to remove the avionics bay cover and go at it from the backside. Then I will take it apart and do a little old fashioned ham radio work on it.

John

I've found the tray gets warped. I've found that I have to use small screwdriver to force the tray bottom flat. Otherwise, it gets hung up about 50% of the time.
 
Never heard of the VAL 2000 before - looks interesting but would require re-mounting and re-wiring. Also I don't see a monitor function, quite handy when you only have one radio,

Yeah, I know the flat fee covers everything - but I don't need all that, my radio looks like new and has only 200 hours on it.

Marty, so far I can't get the *&^*%$ thing out of the rack. It appears to be stuck. I suppose I will have to remove the avionics bay cover and go at it from the backside. Then I will take it apart and do a little old fashioned ham radio work on it.

John
Yes, forgive me for my VAL COM2000 suggestion. I had not had my coffee yet, :)

Yes the mounting would be a pain, whereas you can slip a repaired radio right in. Rocket Bobs suggestions are good. I had an SL-40 (broken) given to me and tracked the problem down to bad display chip (2 digits). I found the part (no longer made) in China for $12, got my younger brother with better eyesight and soldering skills involved, and now have a working SL-40.

Also cleaned the rotary control at the same time.

GH
 
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I had 2 Vals. 1 in the airplane and 1 back at Val getting fixed. Rotated quarterly. When it started blowing my headsets (Val said something was dried up and causing it to blow my Lightspeed headsets) I replaced it with an SL-40. Love it.

To the OP. Just send it off. Sounds like you ride it pretty hard if the knobs are worn.
 
Never heard of the VAL 2000 before - looks interesting but would require re-mounting and re-wiring. Also I don't see a monitor function, quite handy when you only have one radio,

Yeah, I know the flat fee covers everything - but I don't need all that, my radio looks like new and has only 200 hours on it.

Marty, so far I can't get the *&^*%$ thing out of the rack. It appears to be stuck. I suppose I will have to remove the avionics bay cover and go at it from the backside. Then I will take it apart and do a little old fashioned ham radio work on it.

John

John,
One of our RV-12ers had difficulty getting the SL-40 out of the tray. He finally took a small slim blade putty knife, sharpened the edge and slipped it between the bottom of the radio and the upper surface of the tray's bottom skin. Then slip it toward the center and you should feel it move the cam out of the way and the radio should come right out.
 
Thanks Tony. Used a "chip chaser" tool on bottom slot, sure enough the radio came right out. Now to do some trouble shooting.
 
Rocket Bob, do you have any additional details, or a contact for your friend? I am looking at the back of the front board and it has a bunch of surface-mount chips on it. Hard to identify. John
 
Pulled the covers off (had to cut the threatening sticker), and reseated the little cable between the main board and the front-end. It is amazing, the inside of the box is mostly empty space. Not much to these things. Problem went away for a few flights. Then returned worse than ever. Local shops can't service these. Had to send it to Garmin. Flat fee $550 even if problem is one bad 10 cent resistor or the like. Pretty irritating.
 
Garmin

$$$$$ for repairs - that's the reason I would like to be Garminless. Sorry that VAn's chose the Garmin com radio instead of the Dynon com radio. I may have a Garmin com for sale (almost new) after I get my AW cert.:(
 
old design

Keep in mind the SL 40 is a very old design. Garmin purchased it from Apollo years ago. The technology in the radio is also old and hasn't kept up with the latest.

If you decide to replace your radio I highly recommend the Garmin GTR 200. It is a new radio from Garmin utilizing new digital signal processing technology and has lots of extra features that the SL40 doesn't have. Additionally the built-in 2 place intercom compares with the best intercoms out there.
 
GTR200 vs SL40 harness and tray

Keep in mind the SL 40 is a very old design. Garmin purchased it from Apollo years ago. The technology in the radio is also old and hasn't kept up with the latest.

If you decide to replace your radio I highly recommend the Garmin GTR 200. It is a new radio from Garmin utilizing new digital signal processing technology and has lots of extra features that the SL40 doesn't have. Additionally the built-in 2 place intercom compares with the best intercoms out there.
.
Will the GTR200 fit in the same tray and connect to the same wiring already in place for the SL40? If affirmative, then I will consider replacing mine, though it is in good working order.:confused:
 
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