Failed Thron ASQ50

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Zelandeth
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Failed Thron ASQ50

Post by Zelandeth » Sun Mar 02, 2014 10:58 pm

So one of the pair of ASQ50s here decided to pack in this evening.

Was working fine earlier today, no obvious sign of its impending failure, just went to turn it on and it now refuses to start. The tube shimmers briefly, but never actually lights. Sometimes it will just go out, other times it will just keep shimmering indefinitely. Doesn't appear to be the tube, as I switched it for the one from the other fitting and the fault remained (plus this lamp worked fine in the other fitting).

I'll open it up tomorrow to see if I can see any obvious signs of the cause. Anyone want to give odds on the problem being with the cap (5.7uF if I'm reading the text one one of my photos right) rather than the ballast itself? I don't have a huge number of caps in that sort of size in stock, closest I have is 4.7uF, next one up is 10. Would the 4.7 likely work OK (or at least well enough to work as a test as to whether that's the problem), or is the value pretty critical?

Fingers crossed this can be sorted.

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Tom
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Re: Failed Thron ASQ50

Post by Tom » Sun Mar 02, 2014 11:52 pm

I'd say it's highly likely to be the cap! Certainly worth giving the 4.7 a go. Maybe try a 5.5 or a 6uf in there?
I LOVE LAMP!

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Kev
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Re: Failed Thron ASQ50

Post by Kev » Mon Mar 03, 2014 6:48 pm

Yeh cap blew in my one a couple weeks back!

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Paul
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Re: Failed Thron ASQ50

Post by Paul » Mon Mar 03, 2014 9:24 pm

Sounds painful Kev!

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Zelandeth
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Re: Failed Thron ASQ50

Post by Zelandeth » Sun Feb 01, 2015 11:57 pm

Forgot about this thread...sorry!

Replacing the cap with a 4.7uF I had laying around restored normal operation I am pleased to report.

Sadly was only a few days before we moved out..so no idea if the fittings are still there - I did leave a note with my details in the gear tray!

...the 50W Thorn DLN tubes came with me though!

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