Telrad Failure

[AstroNinja]

Hi

My Telrad failed last night (dead from its storage box)  but was fine the last time I used it just two weeks ago.  Admittedly the switch was on (my bad), but I have tried 2 sets of known new batteries, cleaned contacts etc, but no joy.  Does the Telrad reticule wear out over time or burn out?  The unit is about 11 years old, and whilst I have a spare, I'd rather repair than replace if possible.  I appreciate it could also be the switch, although it feels OK and has the "click" .  I see I can get spares from 365 Astronomy.

So curious if anyone else has had the same issue and replaced reticule and/or switch?  I am totally ignorant in electronics but I know people who have better skills than I who could help 

Jon

[Zermelo]

The Telrad reticle is just a mask that sits in front of a red LED. You can buy replacement reticles if there's physical damage, but your problem sounds electrical.

There's a thread here.

[AstroNinja]

Thank you Zermelo

[Louis D]

I had battery corrosion ruin my original.  Replacement battery holder didn't help.  I'm guessing battery out-gassing corroded something in the rest of the unit.

[michael8554]

I've had the red LED fail, and the track on the potentiometer (the brightness control) go open-circuit.

Buy a cheap digital voltmeter and check the volts are getting to the LED.

Michael

[Stu]

On 27/09/2021 at 09:17, michael8554 said:

I've had the red LED fail, and the track on the potentiometer (the brightness control) go open-circuit.

Buy a cheap digital voltmeter and check the volts are getting to the LED.

Michael

I think I have both those problems Michael, can you let me know how you fixed the LED? Seems sealed in to me, how did you access it?

Thanks!

[michael8554]

Hi Stu

I'm afraid I don't remember the details, but it was probably a bodge.

Michael

[Louis D]

I ended up buying a couple of used Telrads at $20 a pop that had potentiometers that only switch between full on and off to replace my original one that died after 18 years.  I just didn't have the time to deal with trying to make the dead one work again.  Check the classifieds to see if you can locate a cheap but partially working Telrad.

[Alma]

I had two of these things fail over time. Nice reticle pattern but too cheaply made i.m.h.o.

[Louis D]

Agreed.  My Rigel QuikFinder is still going strong 22 years after buying it new with the original button cell battery.  It works absolutely like new.  I can't say the same for my 3 Telrads (one new, two used).