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CG5 ASGT Power Switch Replacement

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#1 Eddgie

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Posted 22 August 2013 - 04:38 PM

It seems that power switch failure is a common problem with the ASGT. The normal report is that the switch becomes "Intermittent" and has to be jiggled to get to turn on.

The problem is that sometimes, while you can jiggle it to get the mount on, it will often intermittently drop power.

And the next phase is the "Leave it in on" position, but once again, vibrations can sometimes cause it not to work and you flip the switch on and off a hundred times to try to get it to contact.

Terminal phase is when it just does not come on anymore.

I was at the phase just before terminal, and decided to make a permanent fix.

There are to possibilities. The first is to put a swith in parallel to the old switch and by tacking wires to the power board, but with this method, you have to drill a hole in the plastic case somewhere to mount the switch.

The more elegant method is to replace the switch.

Ah, but finding the switch can be the problem. And who is to say that the new switch will last any longer than the older switch.

I chose to go with the replacement method, but I decided to go with a toggle type switch. The reason was simple. My local electronics store had a double pole single though switch that looked like it would work.

The problem was that the switch was intended for panel mounting and came with solder connection type lugs that were to wide for the circuit board.

Here is the process.

  • Tools
  • 2.5mm Hex wrench (Ball tip is best to save having to remove the mount from the tripod)
  • #1 Phillips
  • Diagonal cutters (small, sharp)
  • Solder "Sucker"
  • Soldering Iron with small tip
  • Solder and flux
  • Small pliers
  • Round file

Disconnect the cables and remove motor cover. There is a Phillips head screw at the top of the cover in a rather deep hole.

There is a 2.5mm Hex head screw at the bottom over the north leg. If you have a ball type hex screw you can get at it. Otherwise you will most likely have to pull the head off of the tripod. You may have to raise the elevation knob to get at it too.

There is what appears to be a screw on the front of the cover but it is an odd little plastic clip. It looks like a Phillips screw head, but you can turn it and it seems to spin like it is stripped. Again, and odd little clip.

Get under it with a sharp object, being careful not to poke your eye out (this is dangerous stuff and you should only attempt to do this if you are brave, good looking, and handy like me). You can pry this litte thing up a bit then pull it out. It is one of those expanding type pins or something. Anyway, that is the way mine is.

Once you do this, the halves of the motor cover will split open.

Inside, you will find the motor board that will fall out. Don't worry, be happy. It is easy to get back in.

The power board is screwed to the port side with two Phillips screws. I taped the three connectors going to the power board all together in order with masking tape so I could preserve the order. If you are anal, you can mark them with tape and fancy little numbers, but hey, there are only three of them and well, how hard could it be to get them back on right?

Now, remove the two screws holding the motor board on.

Enlarge the original switch hole to the size of the new switch mounting shaft with the round file. Easy to do.. two minutes. Unless you want to be careful. Who wants to be carful boys.. Rat that puppy out...

Cut the switch off the power board. If you have a micro-electronics soldering station, maybe you can do it some other way, but with a solder sucker, you won't be able to get the switch out whole most likely. It is almost impossible to get all the solder off of all three pins and there is no way to heat them all at the same time.

Use the dikes and cut the posts.

Now you can use your soldering iron and a needle nose to heat each post and pull away from the board when the solder melts.

I trimmed the connector posts on the new switch. These were about 1/8tg inch with a little hole. I basically cut them to an "L" profile. See the picture.

Now, I knew that the posts would be offset slightly because the original switch had the posts on the centerline. I tried the switch one way and it was canted when it came though the hole in the case, but surprisingly, the other way, it lined up perfectly perpendicular to the case hole.

Now, I soldered the switch into position.

There was no room between the top of the swtich and the case for a nut to hold it from inside the case, but with three posts soldered on to the board, I doubt that it will go anywhere.

The assembly was the opposite of the breakdown but the motor board is held by two small tabs, one in either side case.

Put the port side on the mount, then slip the port side end of the board into the tab on the port side case. Now, when you put the opposite side on you will see that the motor board sits at an angle from the face of the motor casting. There is only one way for it to go on, and just look for the little tabs at an angle. You can't miss them.

Now my install had one fluke. The "1" is not "off" and the "0" is now own. This means that I trimmed the wrong side of the pins but you would have to be a rocket scientist or 50% lucky to figure this out. Ha ha.

Anyway, was a nice change. The new switch is very positive and makes a very nifty "Click". What more could you ask for in a switch.

Downside is that it does stick out a bit. This might be an issue if you transport the mount a lot so this may not be the right switch for you.

If you can find the factory directly replacement, I guess that is good too, and the instructions are exactly the same except for the hole in the cover.

I actually like the toggle switch though. Click. Click. Do it a few times with me... Click. Click.

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#2 Eddgie

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Posted 22 August 2013 - 04:41 PM

The installed switch In all it's glory..

Click.

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#3 Eddgie

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Posted 22 August 2013 - 04:42 PM

Another, form a more flattering angle...

Click.

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#4 Eddgie

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Posted 22 August 2013 - 04:46 PM

The switch I used came from Fry's and was Part Number 35-004.

It is a Single Pole, Double Throw (SPDT) with .25" mounting hole.

Picture:
35-004

And a tip. Dry assemble the switch to the power board and try it in the cover before you solder it into position. You may find like I did that the switch will be canted (at an angle to one side) in one orientation but perfect in the other.

I had already soldered mine in place when I realize the error. No big deal.. Worst case, the 1 and 0 is reversed but hey, there is a red light to tell you what is what.

Also, the red light I don't think comes on until the motor board is connected back.. At least it did not for me. I thought I broke something when I plugged in jus the power board to test it and it didn't work, but when the motor board was plugged in, it was all systems go...

Click.

#5 dmdouglass

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Posted 22 August 2013 - 06:05 PM

Good thread!
Very useful information.
Thank You for sharing your adventure.

#6 frito

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Posted 22 August 2013 - 08:35 PM

good work!

I've been hit with the power jack issues on mine but so far my power switch has been reliable and i'm the mounts third owner (is pretty old too, one of the first versions with updatable firmware judging by the manual and the fact i had to upgrade my firmware to get 2+4 and ASPA)

#7 AstroTatDad

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Posted 22 August 2013 - 10:20 PM

Cool nice job, good to know if I need to ever do this. So far I have been good to go with mine "knock on wood" :)

#8 t.r.

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Posted 23 August 2013 - 11:28 AM

I took mine to a friend who was an electrician at Tycho. He hot wired it to the on position permanantly when the cord is plugged into it. Problem solved. Cost me a beer. :grin:

#9 Eddgie

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Posted 23 August 2013 - 11:48 AM

I thought about that, but it took only a bit more effort for me to replace the switch, and the switch costs about $3 less than a beer at a bar.

I mean if you have to open it up to solder the hot wire in place, for about 10 minutes more effort, you can have a switch.

But that is me.

I get to do the "Click, Click" and I do like it so very much...

#10 t.r.

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Posted 23 August 2013 - 12:30 PM

Incidentily, the AP mounts use the direct power method, no on/off switch. Maybe they know something the rest of the manufacturers don't. ;)

#11 Jason Freeland

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Posted 27 August 2013 - 07:52 PM

I took mine to a friend who was an electrician at Tycho. He hot wired it to the on position permanantly when the cord is plugged into it. Problem solved. Cost me a beer. :grin:


I did the exact same thing even though I had bought a heavy duty switch to replace it with. Much easier.






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