The International Cessna^® 170 Association

Just looking for any guidance you can offer before I waste more of my time than I have to.

One of my strobe lights is not working. It was this way when I bought and wasn't in a position to break the deal over the issue, I hope it don't end up biting me. The seller said it was intermittent so I figured it was a bulb but have not been able to peck it and make it work. He also mentioned that was a power supply in the wing that could be the issue.

Should I be able to look at the bulb to tell if it's burnt out? If so should there be a number on that bulb somewhere or should it be documented in a log book. If the bulb turns out good what next?

Is aircraft spruce a good resource for parts?

Thank you,
Justin

You need to determine what the manufacture is and what model. You will find this on the power supply. Sounds like it might be the kind that has a supply in each wing tip for the respective bulb. And unless the bulb is physically broken you won't be able to tell if it is the bulb or the supply but my money is on the supply or the electrical power to it.

So I need to take the wing tip off to get a look at the power supply to know which bulb to order? I'm guessing that should be my first part to replace. I can surely very power to the power supply with a volt meter before bulb purchase.

Justin

Well if you want to be sure what component is duff and you have a bit of time....well you probably have a few "spares" on the other wing tip you can use to narrow down the issue. As Bruce mentioned determine the manufacturer and yes Spruce sells the bits. The strobe light assy will be plug and play into the power supply so swap bulbs from side to side to see if its the bulb. Not the bulb try swapping the supply. Not the wing tip bits, check at the wing tip for power and ensure you have a ground.

Chances are, the mfr'r has a troubleshooting guide to help you.

First, find out who that is and visit their website.

A simple thing to do is to swap either the lamp, or the power supply from wingtip to wingtip and see if the problem follows. That will isolate the defect.
If no change..then it's likely lack of power to the power supply (of course, you could check that first quite simple.)

If the bulb itself is very dark, then it likely has failed. The exersize above should demonstrate that for you.

Strobe systems which are unused for periods of time often have failed capacitors in the power supply... so if your pwr supply is the problem, send it to the mfr'r for repair. That will likely be cheaper than buying a replacement.

Some folks fly around during daylight (or at high altitudes in Class A airspace) with their strobes off, thinking they're saving them from overuse. That is a mistake.
Strobes last longer with frequent use, and often fail for lack thereof.

Thanks to all for the advice. For some reason it just never crossed my mind to swap the parts around to trouble shoot. That thought seems so simple now that my brain has been informed about it.

As for running the strobes during the daytime. If I can every get them both working they will be running whenever the engine is running as I like the idea of being noticed, for safety of course.


Justin

Be very carefull when working around strobe systems . The voltage is a lot higher than aircraft voltage and if zapped you could have a very bad day . Power going in is ok to check when playing around with the power supply but what comes out can be shocking .

My thought is likely the power supply. The caps go bad or the charging circuit for the caps that build the voltage. Make sure you have power to the supply unit and then if the bulb isn't blown you will need the unit repaired or replaced. I am in the process of sending mine to Whelen for repair. The caps check good so I am sure the unit has another problem.

John

Thanks to everyone for the direction on this.

n3833v wrote: I am in the process of sending mine to Whelen for repair.

Is there a base price on the repairs or is it based on what parts are replaced?

Justin

I was told by my avionics man that they will evaluate and contact you with pricing for repair or replacement.

Go to the Whelen website and ask THEM what they charge. (They have a 24-hour turn-around. I once shipped them my power supply while on a trip to the Tehachapi convention, instructing them which FBO I'd later be visiting enroute, to-whom to ship it. I reinstalled it at one of my overnights and was without a strobe system for only 3 days. The cost, including freight, was $120.)

Here's a troubleshooting guide using their test-rig: http://www.whelen.com/_AVIATION/assets/ ... eCheck.pdf

WARNING: The power supply will store a 400-Volt charge! Discharge it or let it bleed down for at least 5 minutes before handling it!

Ok so I got some time to mess with over the past few days and it does appear to be the the power unit out in the wingtip. Now the bulb does say Whelen on the back but the power unit has "aeroflash signal" on it. Will Whelen still work on this unit or do I have to figure out who these folks are? Anyone had experience with such hardware

Thanks,
Justin

Justin,

I would open up the other wingtip and see what power supply and bulb is there.

Aeroflash is a competing manufacturer to Whelen. You ordinarily wouldn't mix their products though that doesn't mean you can't physically do it. Maybe this is why your strobe doesn't work.

What system does your paperwork say is installed in the aircraft?

Bruce,

Both bulbs are Whelen's and the power supplies are AeroFlash. I moved everything that I could move around to find that it was the one power supply. Found the number for them and they said they only repair less than 5 year old units, and my is 7 years old so yea I get to buy a new one at the low, low price of $93.95. I was expecting worse that is for sure.

Bruce I wasn't sure if you were concerned about that the power supplies might be different or the use or Whelen bulbs with AreoFlash power units.

I was short on time when I looked in my paper work for the strobe kit info so I only got through part of the paper work on the plane and have not found it thus far.

Justin

I do not know but until this moment would have been surprised that Whelen bulbs could be used with Aeroflash controllers. I just thought that the bulbs would not be interchangeable. Apparently that is not the case.

I don't want to open another can of worms. But Aeroflash,though the standard unit for Cessna at least at one time, does not or did not have a STC to install them in a 170. So I had to get an approval for the Aeroflash system I found in my airplane. It was not a big deal with the Fedsto approve it.