Strobe light not working.

[J170 Owner]

Hello. My strobe has failed. The fault is in the control box, not the light. Pulling the box apart and a quick check with the multimeter shows the fuse link on the PCB is open circuit. Without a circuit diagram it is tricky to fault find. All the semiconductors measure as expected but that's no guarantee they're all good. So, anybody got a circuit for a "Single magnum SMART STROBE made by Kuntzleman Electronics"? Standard unit fitted to the Jabiru J170C

 

Thanks.

 

PS: I am an electronics technician, I know what end of the soldering iron to grab!

 

 

[petetheprinta]

Bummer!!!

 

 

[J170 Owner]

Bummer!!!

Hello young man. The strobe is not a mandatory item so I can fly without it. Over $100 for a new box so I shall give fixing it my best shot. I'll ring Jacar tomorrow to see if they stock some bits I suspect are dead.

 

 

[Herm]

Hello. My strobe has failed. The fault is in the control box, not the light. Pulling the box apart and a quick check with the multimeter shows the fuse link on the PCB is open circuit. Without a circuit diagram it is tricky to fault find. All the semiconductors measure as expected but that's no guarantee they're all good. So, anybody got a circuit for a "Single magnum SMART STROBE made by Kuntzleman Electronics"? Standard unit fitted to the Jabiru J170CThanks.

 

PS: I am an electronics technician, I know what end of the soldering iron to grab![ATTACH=full]18561[/ATTACH]

Are you sure it's the board? I have fixed a couple of these and found it to be the Xeon bulb that had failed. If not its most likely an IC or transistor. I would replace them all. Go to Aztronics at gepps cross as Jaycar have bugger all in odd IC's

 

Mardy

 

 

[Kyle Communications]

J170

 

Herm is right you don't need a circuit just test all the resistors and diodes if they are all ok then just replace the other semiconductors you cant test with the multimeter or peak tester. It is the quickest and easiest way to repair it. Though of course it could be the actual tube that caused the fuse to blow so you need to check that first.

 

I had the Qld university ring me up to repair some funky light wavelength test equipment they couldn't fix with all their super smart engineers this thing was worth 100,000 bucks. Half of it worked the other half didn't. Both sides were the same so all I did was swap the pcb boards over to find which one didn't work then just tested all the passives and they were ok so I went and got a complete set of chips which totalled about 10 I think then replaced them all and bingo it worked perfect. Total cost of the chips was about $15.00

 

They couldn't believe it only took 2 days...so you just need to think a little outside the box there are easy ways to do things if you think about it.

 

Mark

 

 

[cscotthendry]

For my money, I'd go straight for the two high voltage Electros. In a strobe circuit, those things are worked pretty hard.

 

BTW, It could just be the pic, but the electro nearest the missing fuse link looks a little bulgy on top.

 

 

[J170 Owner]

Are you sure it's the board? I have fixed a couple of these and found it to be the Xeon bulb that had failed. If not its most likely an IC or transistor. I would replace them all. Go to Aztronics at gepps cross as Jaycar have bugger all in odd IC's

 

 

Mardy

I think after 35 years as an electronics technician I could determine that the board was at fault.

 

 

[Guest Andys@coffs]

So from one tech to another.....I'd be looking at the high voltage switching circuitry...SCR, TRIAC DIAC (trigger diode). Electro's...not so sure...my experience (limited over the last 15 years) is that high voltage electro's bulge as their electrolyte evaporates and internal equiv resistence rises. The photo appears to be bulgeless (and thats in no way definative)

 

Switching semi's even on a swap without testing are likely to leave you with change from a $10 note.

 

Were you able to see that the main electro charged up to a high voltage and held? ....(umm in retrospect stupid Q cause the fuzible link did!!)

 

Andy

 

P.S Mardy may still be right, the tubes do have a finite life on them..... Im just not convinced that when they they reach that count they will cause a link to blow....

 

 

[Guest Andys@coffs]

J170Herm is right you don't need a circuit just test all the resistors and diodes if they are all ok then just replace the other semiconductors you cant test with the multimeter or peak tester. It is the quickest and easiest way to repair it. Though of course it could be the actual tube that caused the fuse to blow so you need to check that first.

 

I had the Qld university ring me up to repair some funky light wavelength test equipment they couldn't fix with all their super smart engineers this thing was worth 100,000 bucks. Half of it worked the other half didn't. Both sides were the same so all I did was swap the pcb boards over to find which one didn't work then just tested all the passives and they were ok so I went and got a complete set of chips which totalled about 10 I think then replaced them all and bingo it worked perfect. Total cost of the chips was about $15.00

 

They couldn't believe it only took 2 days...so you just need to think a little outside the box there are easy ways to do things if you think about it.

 

Mark

Thats cause being able to design it, still doesnt embed a lifetime of logical faultfinding experience. If you asked the engineer how Successive Approximation A to D's work he'll tell you, using exactly the same process of splitting in half and testing for failure at that point may not have been overly apparent.... Give them a bunch of wheel spinning hours and they would have come up with it eventually....

 

Andy

 

 

[aj_richo]

Any electronic technician worth his salt would just reverse engineer the circuit diagram from the board, its not enscapulated. so whats the problem?

 

 

[cscotthendry]

From the looks of the board, it appears as though J170 already has his suspicions as to the guilty. I see a some components around SCR2 missing.

 

But yeah, I was also thinking that if Kuntzelman won't supply a schematic it shouldn't be too hard to trace one out. They don't seem to have made any effort to disguise components or encapsulate it to prevent RE.

 

 

[Thirsty]

we had one of these fail on a J160 recently. It was found to be the copper wire wound thing (Inductor? I'm definately not an EE!). I tested the whole system with an AM radio as advised by Jabiru and I could hear the pulses but the tube wasn't lighting up (it's a new tube as well).

 

 

[J170 Owner]

I'm sorry I posted this king thread....

 

 

[Herm]

I

 

I'm sorry I posted this king thread....

gIts fair to say that we just wanted to give advice as its not a real complicated situation for a tech. I know you asked for a diagram and it seems no one has one, so assistance was given... That's what helpful forums do for you.. It does sound like most of us think you should be able to sort this out without too many problems or cost. Now we all know you are also a Tech, I recon you should have it in the bag. I will be watching for the flashing in Gawler

 

Mardy

 

 

[frank marriott]

I'm sorry I posted this king thread....

As a radio tech myself - if you locate a circuit diagram I would be keen to get a copy. At this stage I do not have a problem but a circuit diagram would be nice to have on file for the future.

 

FrankM

 

 

[techie49]

I'm sorry I posted this king thread....

More to the point, have you mended it yet?

If so what was the problem?

 

If you haven't and want some help, give me a shout

 

Paul

 

 

[Guernsey]

They are not problems just technical challenges.

 

I was a tech in the previous century so I would have changed all of the valves at least twice then changed every resistor or capacitor one at a time until the challenge was met.

 

Alan.

 

PS that board must run very hot as that is one hell of a big oil cooler at the top right of picture.

 

 

[J170 Owner]

I worked part time Saturday mornings in a TV repair shop before getting my apprenticeship as a Radio Tradesman. The fellow there was a 'valve jockey'. He basically changed everything until the TV or whatever worked properly.

 

The strobe box had a dicky diode (D2) and MOSFET (IRF644). The strobe light however only fires occasionally (in the plane) and I suspect water as it is certainly evident around the base of the flasher housing, perhaps that is what killed the thing in the first place? The box itself is ticking over like a pace maker on steroids. I left the thing running in my workshop for a few hours. The oil cooler must be doing a good job because nothing gets hot, if you stick your fingers on the trigger wire, you can do aerobatics without a plane. Just for the record, there are now high intensity LED flashers available so that might be an option down the track.