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Fixed : Autostar 495 handset

pmf

By pmf
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pmf

pmf

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Hi, This is my first attempt at a post as I just joined. I thought I would share something that might be helpful. A while ago, my beloved Meade LXD55 started mis-behaving and it looked like gremlins in the Autostar controller handset. Initially it would start madly slewing at full speed. Eventually I figured out that this was likely to happen when the car battery that I powered it from was going flat. It seems that the low-voltage condition causes the software in the handset to loose its marbles and start a mad slew. SInce I replaced the power source with a 12-Volt 5-Amp regulated supply "liberated" from a Freesat set-top-box that particular fault was fixed.

However, more recently the handset started to fail to boot up properly. It would give a lethargic beep, put up the "Welcome" message but then stall. Sometimes it could be persuaded to work if re-tried a few times. Sometimes it was better if the GPS ("StarGPS" unit) was detached.

Then it started randomly stopping mid-session - ruining everything, and yesterday, it just refused to boot up properly at all despite coaxing.

So, I took it appart. There was one Electrolytic Capacitor (100 uF) sat there on the board, and I decided that it looked guilty. To cut a long story short, replacing this but snipping its legs and soldering on a replacement (the right way round) and now the 'scope is restored to its full function.

I suspect that 10 years living outside in the observatory makes it reasonably likely that the electronics just gets tired out like this and the electrolytics are the number one culprit.

Anyway, very happy that it now works, and thought I would share the experience in case anyone else had similar troubles.

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Stu_2011

Stu_2011

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Hi, This is my first attempt at a post as I just joined. I thought I would share something that might be helpful. A while ago, my beloved Meade LXD55 started mis-behaving and it looked like gremlins in the Autostar controller handset. Initially it would start madly slewing at full speed. Eventually I figured out that this was likely to happen when the car battery that I powered it from was going flat. It seems that the low-voltage condition causes the software in the handset to loose its marbles and start a mad slew. SInce I replaced the power source with a 12-Volt 5-Amp regulated supply "liberated" from a Freesat set-top-box that particular fault was fixed.

However, more recently the handset started to fail to boot up properly. It would give a lethargic beep, put up the "Welcome" message but then stall. Sometimes it could be persuaded to work if re-tried a few times. Sometimes it was better if the GPS ("StarGPS" unit) was detached.

Then it started randomly stopping mid-session - ruining everything, and yesterday, it just refused to boot up properly at all despite coaxing.

So, I took it appart. There was one Electrolytic Capacitor (100 uF) sat there on the board, and I decided that it looked guilty. To cut a long story short, replacing this but snipping its legs and soldering on a replacement (the right way round) and now the 'scope is restored to its full function.

I suspect that 10 years living outside in the observatory makes it reasonably likely that the electronics just gets tired out like this and the electrolytics are the number one culprit.

Anyway, very happy that it now works, and thought I would share the experience in case anyone else had similar troubles.

Thanks, good first post...resulting in a fix which is always good.

I have noticed that electrolytic capacitors always seem to fail so a good pace to start. I think the fluid dries out / corrodes in-between the metal pates and it causes problems. A friend of mine who is an electronics whizz always checks out capacitors first for some reason....

Stu

Sent from my iPad using Tapatalk

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pmf

pmf

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Thanks for all the kind comments.

I agree with Stu_2011 that the cap's dry-out and fail.

What put me onto it was that it started to be "iffy" about powering up and gradually got worse - until completely incapable of powering up. This would be due to it gradually drying out and getting worse and worse.

Thankfully there is only one in there, so it was the obvious thing to try.

Paul

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