mooney panel lights

[Gmooney]

The mooney I have is equipped with panel lights.  During landing the lights went out and I have not been able to get them back on.  I have checke the circuit breakers but no luck.  Anybody with advice

[tony]

The post lights on the panel? Mine was feed with a lousy 24 gauge solid wire and the same for the ground. I have no idea if that was original or something that was done during her life. Anyway, I found a broken wire 12 volt feed.

[RonM2OC]

Where did you find the wire break?

[RonM2OC]

mooney panel lights
I have a M20C 1975. The lights above my instrument panel are connected in a set of four circuits and one ground bare wire to all the lights. The white lights on the right side are out and the red lights on the left side are also out. A day/night switch selects which color (works). A voltage check shows no voltage to the two cicuits that are out. The variable resister works on the working lights. The wiring diagram only shows one wire to the lights fron the variable switch which is just under the throttle quad. Is there a hidden fuse somewhere? Any clues? Thanks all

[jetdriven]

1977 M20J has two Buss F-01 fuses mounted under two tiny gray screw caps in the dimmer.  look at them.

[Hank]

My C has a knob up high, right beside the push-to-test button, that is used to turn the interior lights on and off. Both the push-to-test and the rotary knob are attached to a small circuit board behind the panel. I smoked a piece on mine two years ago September and had to replace the whole board. Could not find schematic of the board, and there was not enough left of whatever-it-was to identify for replacement. Good luck!

[DanM20C]

Quote: Hank

My C has a knob up high, right beside the push-to-test button, that is used to turn the interior lights on and off. Both the push-to-test and the rotary knob are attached to a small circuit board behind the panel. I smoked a piece on mine two years ago September and had to replace the whole board. Could not find schematic of the board, and there was not enough left of whatever-it-was to identify for replacement. Good luck!

[Hank]

First make sure that littel board is your problem. Then call every aircraft salvage yard and long-time A&P whose number you can dig up. Cross your fingers, throw salt over your shoulder, knock on wood, light candles and pray. Took me several phone calls to find one with one more connection than was on my board; the owning A&P sent it to my avionics guru [an hour's flight away] who compared it to the toasted board; he then sent it to my A&P to test-fit and compare plugs & wires; then I mailed a check off to the long-time Mooney guru in Barnwell(?) OH--Clyde/Claude Whittendorf? It was the only one he had two years ago, removed from an F maybe, but he's still worth a try if his shop is still open. I think he worked with Al to refine the original prototype.

[DanM20C]

Quote: Hank

First make sure that littel board is your problem. Then call every aircraft salvage yard and long-time A&P whose number you can dig up. Cross your fingers, throw salt over your shoulder, knock on wood, light candles and pray. Took me several phone calls to find one with one more connection than was on my board; the owning A&P sent it to my avionics guru [an hour's flight away] who compared it to the toasted board; he then sent it to my A&P to test-fit and compare plugs & wires; then I mailed a check off to the long-time Mooney guru in Barnwell(?) OH--Clyde/Claude Whittendorf? It was the only one he had two years ago, removed from an F maybe, but he's still worth a try if his shop is still open. I think he worked with Al to refine the original prototype.

[jbreda]

There is a great electronics parts store near me.  It is called You Do It Electronics, Needha, Massachusetts.  They have a large selection of parts and can order many more.  You might try them.

If not, it may be time to replace the circuit with new stuff.

John Breda

[jetdriven]

You guys are in luck, seeing as how I managed to blow up both panel light transistors and the FM-01 fuses as well.  The transistors get loose in the mount and the legs short out to ground, killing them.  The old transistor on mine is a 2N2016 I bet yours is as well. This is a NPN silicon transistor.  They are no longer available. I replaced them with 2  2SC5200 transistors, which are also NPN but the newer MOSFET design and 230V 15A 150W rated. An alternate is the 863-MJH11020G whihc is 200W.  Bolt them up and dont forget the thermal paste underneath them, they transfer a lot of heat. Wire the emitter, collector, and base you are ready to roll.  Cheap as well.  From Mouser electronics, the same source for the FM-01 fuses, which I would guess you need 2 of as well.  Here is some info in the photos.

 

 

[jetdriven]

old 2N2016 info

new 2SC5200 info

 

I forgot the thin plastic wafer under the old transistors must be modified and reused.  You cannot allow the rear of the transistor or the screw  to make electrical contact to the mount.

 

 

[carusoam]

You-do-it is great.  Bought a build it yourself Ham radio receiver and other science projects there back in the mid 70's...

Thanks for the reminder John.

Best regaahds,

-a-

[DanM20C]

Quote: jetdriven

You guys are in luck, seeing as how I managed to blow up both panel light transistors and the FM-01 fuses as well.  The transistors get loose in the mount and the legs short out to ground, killing them.  The old transistor on mine is a 2N2016 I bet yours is as well. This is a NPN silicon transistor.  They are no longer available. I replaced them with 2  2SC5200 transistors, which are also NPN but the newer MOSFET design and 230V 15A 150W rated. An alternate is the 863-MJH11020G whihc is 200W.  Bolt them up and dont forget the thermal paste underneath them, they transfer a lot of heat. Wire the emitter, collector, and base you are ready to roll.  Cheap as well.  From Mouser electronics, the same source for the FM-01 fuses, which I would guess you need 2 of as well.  Here is some info in the photos.

 

 

[jetdriven]

That schematic is from a 1976 M20F Service and Maintenance Manual.  However the note on the schematic says its effective from SN 24-0071 and on, whihc would be a J model.  Mine is configured just like that one, wire numbers and all. Its a 77 J SN 24-0162.  I think yours will be very similar.  I swapped out the transistors with MOSFET transistors, soldered them up and heat shrinked all the legs, then bolted them in and connected the wires.   It takes a couple hours but worth it.  Here is a better screen shot of the schematic.  Holler if you need additional or more info.

 

 

[Barry]

Quote: jetdriven

 I swapped out the transistors with MOSFET transistors, soldered them up and heat shrinked all the legs, then bolted them in and connected the wires.

 

[jetdriven]

Barry do you have a better part number for replacing the 2N2016?  Mouser said it would work fine.  Those old ones get warm in use as well, they had thermal paste under them.

[DanM20C]

Quote: Barry

 Interesting it worked. A 2N2016 bipolar transistor and a MOSFET are biased entirely differently ... the MOSFET working more like the old electron tubes by clamping the electron flow by reverse biasing the gate and the bipolar transistor by forward biasing the base/emitter junction and reverse biasing the base/collector junction.

     Maybe that is why it's getting hot...

[DanM20C]

I just checked the transistors with a diode tester.  The 2N2016 is toast, but the other one the 2N442 seems fine.  I'll start by replacing the 2N2016 with the 2SC5200 as jetdriven did.  I can't find any other bad component on the board.  Hopefully this will be a $3 fix.  If not, I might have to take Hanks advice and get out the salt and candles. 

Dan

[Hank]

That was required because i couldn't find a schematic to repair my board. Be happy that you have the option.

[jetdriven]

I just wired up the collector, emitter, and base to the wires that came from the old transistor.  I was unter the idea a 2SC5200 was a MOSFET but im glad it isnt.

[Barry]

forgot the link    :9)

[Barry]

Here's a link to a 2N2016, but it's $124.95. Would have to do research to see what else can be used. Maybe easier to re-design the circuit ... but then ... is that legal ??

 

http://store.americanmicrosemiconductor.com/2n2016.html?gclid=CNT5pMqdgKsCFUHe4AodpjEC0w

[scottfromiowa]

Or...install nu-lite (bezel lites) with dimmer to replace six pack/non internally lit gauges.  The price is reasonable.  The result is superior to OEM.

[danb35]

Or just use a PMA'd dimmer like the MaxDim (http://www.maxpulsemaxdim.com/maxdimmini.htm).