---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 04/21/09: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:01 AM - Re: Re: Low Voltage Warning (mike gamble) 2. 08:01 AM - Re: MX20 vertical stripes (Phil Samuelian) 3. 08:19 AM - 757 mic bias voltage (Greg Young) 4. 10:11 AM - Re: 757 mic bias voltage (Robert L. Nuckolls, III) 5. 04:03 PM - Re: WIRE Strippers are back . . . (Jim McBurney) 6. 05:58 PM - Re: MX20 (Angier M. Ames) 7. 06:38 PM - Re: Re: MX20 (Bill Bradburry) 8. 06:41 PM - Re: Re: MX20 (Bob White) 9. 07:00 PM - Re: Re: MX20 (earl_schroeder@juno.com) ________________________________ Message 1 _____________________________________ Time: 06:01:45 AM PST US From: "mike gamble" Subject: Re: AeroElectric-List: Re: Low Voltage Warning Yes please Eric. I'll take you up on your offer. Would you send me a copy of the LV light schematic? Thanks Mike Gamble UK Europa builder ________________________________ Message 2 _____________________________________ Time: 08:01:17 AM PST US From: Phil Samuelian Subject: Re: AeroElectric-List: MX20 vertical stripes I too, experienced the vertical stripe problem a few years ago, but was fortunate that the MX20 was under warranty. I was told by UPS/ Garmin that it was caused by moisture contamination. I am guessing that on battery power (on the ground) your MX20 is operating at a lower voltage, and the stripes are not showing up due to reduced backlighting of the LCD. I am almost 100% sure that the cause is unrelated to the alternator or other external factors. LCDs have hundreds of connections surrounding the edge of the glass substrate, and the behavior of the LCD suggests that there are 1 or more intermittent connections. As Greg from the 480 group on Yahoo discovered, smacking the LCD around a bit can fix or at least change the problem (for better or worse). Smacking it around is not recommended, because the LCD is a delicate component and can be permanently damaged. For those that want to attempt a repair and are willing to accept the possible consequences... There is usually a rectangular sandwich of alternating metal strips and elastomeric material that is used to form the connection between the glass and driver PCB. The ability of this sandwich to connect depends on cleanliness and pressure. Both must be maintained for proper operation. Good luck. On a side note, there are at least 2 versions of the MX20 display. The original, and an improved version that has faster rendering. If you send it in for repair, you might get back a better product. Phil RV7, C177 On Apr 20, 2009, at 5:42 AM, Ralph E. Capen wrote: > > > > Folks, > > I am about 11 hours in to my flyoff hours for my RV6A and have > found what I think is an alternator-based electrical anomaly. > > When I operate my radio stack from battery power (on the ground) - > everythings fine. > When I operate my radio stack from alternator power, I get single > pixel wide vertical colored stripes on my MX20 display. The stripes > don't change with RPM - they just show up when I turn the unit on > and annoy me. > > I still need to determine if it is the B&C 60 or the B&C SD20 making > the stripes appear. I'm guessing that it's the 60 since the 20 is a > backup that doesn't kick in while the 60 is running. This should be > an easy test though as I have individual control of each > alternator..... > > I'll verify good grounds and bonds next weekend. I did not install > any additional grounds/bonds/shielding other than what was specified > in the install manual and wiring diagrams. > > I'll be sending this to the Garmin tech support folks to see what > they say too - but I'm fairly certain that I can get good scoop here. > > Thanks, > Ralph > RV6A N822AR @ N06 10.7hrs in to the fly-off period ________________________________ Message 3 _____________________________________ Time: 08:19:55 AM PST US From: "Greg Young" Subject: AeroElectric-List: 757 mic bias voltage I've got a friend that flys 757's using a Bose headset and has the mic get hot (warm) during the course of a flight, not burn-your-lips-hot, but too hot. Talked to the Bose service mgr here at Sun n Fun and he wants to know what the mic bias voltage is since a replacement mic didn't fix it. FWIW, the mic is live continuously because of the CVR. I thought there might be someone in the brain trust here that might know the answer or have any other ideas. It's not a problem in GA aircraft - he flew with me to SnF in my Navion for 5 hrs and had no problem. Likewise none in his GA airplanes. Regards, Greg Young ________________________________ Message 4 _____________________________________ Time: 10:11:52 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 757 mic bias voltage At 10:13 AM 4/21/2009, you wrote: >I've got a friend that flys 757's using a Bose headset and has the >mic get hot (warm) during the course of a flight, not >burn-your-lips-hot, but too hot. Talked to the Bose service mgr here >at Sun n Fun and he wants to know what the mic bias voltage is since >a replacement mic didn't fix it. FWIW, the mic is live continuously >because of the CVR. I thought there might be someone in the brain >trust here that might know the answer or have any other ideas. It's >not a problem in GA aircraft - he flew with me to SnF in my Navion >for 5 hrs and had no problem. Likewise none in his GA airplanes. Don't know what the Bose "ratings" are but in situations where I've had occasion to put a voltmeter across an active mic in a TC aircraft, measurement were always in the 3-5 volt range. A simple check of his mic while plugged into the ship's audio system may show a lot more. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 5 _____________________________________ Time: 04:03:54 PM PST US From: "Jim McBurney" Subject: Re: AeroElectric-List: WIRE Strippers are back . . . Bob, Don't feel old. I was assisting in a class of young A&P's, in the electrical unit. I made the comment, "Dikes are good strippers"! You might guess the looks and comments I got! Blue skies and tailwinds Jim CH-801 DeltaHawk diesel Augusta GA 90% done, 90% left ________________________________ Message 6 _____________________________________ Time: 05:58:58 PM PST US From: "Angier M. Ames" Subject: AeroElectric-List: Re: MX20 Interesting that the Apollo MX20 is a current subject of discussion here. I have a wiring problem in my Lancair avionics stack which so far defies a solution. 14 volts is applied to the MX20 through pins 1 &16 and ground through pins 2 & 20 on the 37 pin Dsub connector J1. The only other connections on J1 are RS232 data lines. On the bench and with power & ground connected, the MX20 functions normally. In the avionics stack there is a GX60, SL30, SL70 and they all function and talk to each other correctly. At the back of the MX20 chassis, sockets 1 & 16 and 2 & 20 have correct polarity and 12.8 volts. The problem is simply that when the MX20 is seated normally in its chassis in the stack, is gets no power, nothing, zip, nada.... If I remove the MX20 from the stack and set it on the wing and connect 3' jumpers between the pins on the MX20 and the sockets at the rear of the chassis, the MX 20 powers up normally. For the moment, I'm completely stumped. Angier Ames N4ZQ ________________________________ Message 7 _____________________________________ Time: 06:38:14 PM PST US From: "Bill Bradburry" Subject: RE: AeroElectric-List: Re: MX20 Pins or sockets may not be seated in the connectors? B2 -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Angier M. Ames Sent: Tuesday, April 21, 2009 8:56 PM Subject: AeroElectric-List: Re: MX20 --> Interesting that the Apollo MX20 is a current subject of discussion here. I have a wiring problem in my Lancair avionics stack which so far defies a solution. 14 volts is applied to the MX20 through pins 1 &16 and ground through pins 2 & 20 on the 37 pin Dsub connector J1. The only other connections on J1 are RS232 data lines. On the bench and with power & ground connected, the MX20 functions normally. In the avionics stack there is a GX60, SL30, SL70 and they all function and talk to each other correctly. At the back of the MX20 chassis, sockets 1 & 16 and 2 & 20 have correct polarity and 12.8 volts. The problem is simply that when the MX20 is seated normally in its chassis in the stack, is gets no power, nothing, zip, nada.... If I remove the MX20 from the stack and set it on the wing and connect 3' jumpers between the pins on the MX20 and the sockets at the rear of the chassis, the MX 20 powers up normally. For the moment, I'm completely stumped. Angier Ames N4ZQ ________________________________ Message 8 _____________________________________ Time: 06:41:49 PM PST US From: Bob White Subject: Re: AeroElectric-List: Re: MX20 Hi Angier, Do a visual check on the pins in the mating 'D' connector. They should all line up and be the same depth in the socket. Crimp pins can be out of alignment if they aren't seated correctly, and solder pins can move around during the soldering process if the cable builder get a little carried away heating the pins. The plastic gets soft allowing the pin to move around. May not be the problem, but worth a check. Bob W. On Tue, 21 Apr 2009 20:56:17 -0400 "Angier M. Ames" wrote: > > Interesting that the Apollo MX20 is a current subject of discussion > here. I have a wiring problem in my Lancair avionics stack which so > far defies a solution. 14 volts is applied to the MX20 through pins 1 > &16 and ground through pins 2 & 20 on the 37 pin Dsub connector J1. > The only other connections on J1 are RS232 data lines. On the bench > and with power & ground connected, the MX20 functions normally. In > the avionics stack there is a GX60, SL30, SL70 and they all function > and talk to each other correctly. At the back of the MX20 chassis, > sockets 1 & 16 and 2 & 20 have correct polarity and 12.8 volts. The > problem is simply that when the MX20 is seated normally in its chassis > in the stack, is gets no power, nothing, zip, nada.... > > If I remove the MX20 from the stack and set it on the wing and connect > 3' jumpers between the pins on the MX20 and the sockets at the rear of > the chassis, the MX 20 powers up normally. > > For the moment, I'm completely stumped. > > Angier Ames > N4ZQ > > > > -- N93BD - Rotary Powered BD-4 - http://www.bob-white.com 3.8 Hours Total Time and holding Cables for your rotary installation - http://roblinstores.com/ ________________________________ Message 9 _____________________________________ Time: 07:00:46 PM PST US From: "earl_schroeder@juno.com" Subject: Re: AeroElectric-List: Re: MX20 ---------- Original Message ---------- From: "Angier M. Ames" >in the stack, is gets no power, nothing, zip, nada.... In school we would discretely put a piece of scotch tape in the connector as a test and baffle our 'buddies'... Probably not your problem but might be worth checking.. Earl ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.