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neotesla
Pooh-Bah
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Reged: 11/18/10

Loc: Canada
Re: 12" LX200 classic with fuse problems new [Re: jcarr]
      #4818384 - 09/20/11 02:58 PM

Quote:

...(I think I have a soldering iron around here somewhere, oh wait that's a propane torch... this is going to be ugly)...




I always hated trying to desolder capacitors and other small bits on boards, until I got a Dremel tool. Used the cutting disks to remove the components, and gently grind flush the surface. Using the smallest bits I could find (same size as the wires on the caps and resistors), drill the hole out, thread the new piece in and solder. This reduced the damage I got in the past from overheating the board and damaging the circuits. So you can put away your propane torch!


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jcarr
newbie


Reged: 06/12/11

Loc: Sandusky, Ohio
Re: 12" LX200 classic with fuse problems new [Re: Christopher Erickson]
      #4818751 - 09/20/11 05:52 PM

I might be able to bribe an I&C tech or two at work with lunch... I don't think they even go down to the component level any longer out there... it's usually just chuck the card out and replace it with a new one!

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Brian Risley
Carpal Tunnel
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Reged: 09/04/06

Loc: SW Florida
Re: 12" LX200 classic with fuse problems new [Re: jcarr]
      #4819022 - 09/20/11 08:56 PM

Jeff, Welcome to CN!
As you have found out, the guys here do know there stuff.
Feel free to ask any questions, we all have been newbies in one area or another.
(Yeah, I got started in computer repair when you could replace an IC and fix things (and the manufacturers allowed it!), now its rare to do that!)

Brian


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Stewww
super member
*****

Reged: 06/29/10

Loc: Memphis, IN
Re: 12" LX200 classic with fuse problems new [Re: Christopher Erickson]
      #4819616 - 09/21/11 08:06 AM

Sorry if redundant as I just did a speed read.

Look at the round (electrolyte) caps and see if any are bulging at the top. If so it's definitely bad.

A metric poo poo ton of bad caps found their way in to electronics some years back. If a piece of electronic equipment goes bad check for bad caps.

I know a guy at work that fixed his HD TV by replacing a few caps and I have fix several PC Motherboards that had them.

http://en.wikipedia.org/wiki/Capacitor_plague


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scotty693
newbie


Reged: 01/06/13

Re: 12" LX200 classic with fuse problems new [Re: Stewww]
      #5608799 - 01/06/13 04:47 PM

Hello everyone this is my first post here so "hi". Well i switched my LX200 classic on for the first time in about 3 years, (its about 8 years old), poof went C1 on the power board. Tantalum capacitor literally blew its top off. Obviously my lx200 is just so much scrap now, it just slews in RA at full speed madly. I will replace C1 and C3 tomorrow with a Tant 10uF 35V from Maplin (UK component store) and see what happens, but i wonder if there is more damage now, or if this will fix it. What is the experience of others and what are my other options. I believe there is a recgonised expert who sells some sort of upgrade here (i.e George Dudash). Now i have studied electronics and have an oscilloscope so i could do some detailed tests, but i have not done this for years, and know nothing of the circuits in this scope. I also do not intend buying a replacement since the skies are now so awful in the uk its a waste of money in my view (permanent cloud these days , so it seems at least in Basingstoke UK ).

Edited by scotty693 (01/06/13 04:53 PM)


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Christopher EricksonModerator
Carpal Tunnel
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Reged: 05/08/06

Loc: Waikoloa Village, Hawaii
Re: 12" LX200 classic with fuse problems new [Re: scotty693]
      #5609533 - 01/07/13 12:34 AM

Ron Sampson repairs LX200 classic electronics and he can be reached at rsampsonus "at" yahoo.com

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scotty693
newbie


Reged: 01/06/13

Re: 12" LX200 classic with fuse problems new [Re: Christopher Erickson]
      #5610535 - 01/07/13 04:30 PM

any solutions based in the UK , out there ?

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Christopher EricksonModerator
Carpal Tunnel
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Reged: 05/08/06

Loc: Waikoloa Village, Hawaii
Re: 12" LX200 classic with fuse problems new [Re: scotty693]
      #5610566 - 01/07/13 04:48 PM

Quote:

any solutions based in the UK , out there ?




Non that I am aware of but Ron Sampson receives LX200 Classic electronics from all over the world for repair. You just remove your boards, cables, motors and hand controller and arrange shipment according to Ron's advice. You will get them back in about 2-4 weeks, all-repaired.

He has an excellent rep.


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neotesla
Pooh-Bah
*****

Reged: 11/18/10

Loc: Canada
Re: 12" LX200 classic with fuse problems new [Re: Christopher Erickson]
      #5610594 - 01/07/13 05:13 PM

Found this in an old post, it was for repair of a Meade RCX400 scope, but as suggested by the post, they may be able to help...

"The guy to speak to in the UK regarding your RCX problem is Steve Collingwood, the service guy from Telescope House (main UK Meade dealers) he knows all about RCX's..."

http://www.telescopehouse.com


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orion61

*****

Reged: 10/20/07

Loc: Birthplace James T Kirk
Re: 12" LX200 classic with fuse problems new [Re: neotesla]
      #5610766 - 01/07/13 07:21 PM

I replaced my caps in my handset but in the long run I
got the Autostar upgrade on my 12"
I kept my old electronics and figured if the price on the origonals ever hit $200.00 I'd sell them...LOL
I still love the Classic LX200 and still think back on how amazing these were, and to me still are.
Mine still does everything I want a scope to do and probably ever will.
Chasing the Space station well.. that might be cool but not the highest thing on my list.
I have my 12" Big gun, my 7" Lx200 for Planetary and Doubles
The old C8 and 102 ED for quick but serious, and the 127 NexStar SLT with a very much needed tripod upgrade for Grab and Go.
Life is good


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scotty693
newbie


Reged: 01/06/13

Re: 12" LX200 classic with fuse problems new [Re: orion61]
      #5611855 - 01/08/13 12:23 PM

thank you all for that i shall make contatc with Ron, and speak to telescope house.

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Mike Boessen
journeyman


Reged: 05/31/10

Re: 12" LX200 classic with fuse problems new [Re: TheWabbit]
      #5644695 - 01/26/13 04:37 PM

Hi, Wabbit: I have repaired 3 LX 200's that have had this problem. My advice concerning the hand controller is to chuck it and get the wireless one from Meade. SWEET! I have an original that I have replaced the capacitors in. I'd sell it for 80 bucks if you are stuck on that idea, though.
I was not able to filter out what conclusion you reached. ALL tantalums should be replaced with electrolytics. NEVER use a tantalum. If you are using the 12v to 18v power adapter from Meade, this is a POS. It should have a 10 amp Hexfred diode put across the output and an inline fuse added.
Most of the time when these tantalums blow they take out a couple of ic's on the motherboard. If you are back in business, fine. If not, let me know and I can maybe help you out. They are cheap and easy to replace.

One other note of warning. The RA and DEC drives can get a little noisy in these things. A lot of people try to take them apart and lube them. It's easy to mess up the encoders doing that. If you aren't really comfortable with doing this, get someone experienced to do it.

Hope you are back in business.


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Christopher EricksonModerator
Carpal Tunnel
*****

Reged: 05/08/06

Loc: Waikoloa Village, Hawaii
Re: 12" LX200 classic with fuse problems new [Re: Mike Boessen]
      #5647104 - 01/27/13 10:38 PM

Quote:

Hi, Wabbit: I have repaired 3 LX 200's that have had this problem. My advice concerning the hand controller is to chuck it and get the wireless one from Meade. SWEET! I have an original that I have replaced the capacitors in. I'd sell it for 80 bucks if you are stuck on that idea, though.
I was not able to filter out what conclusion you reached. ALL tantalums should be replaced with electrolytics. NEVER use a tantalum. If you are using the 12v to 18v power adapter from Meade, this is a POS. It should have a 10 amp Hexfred diode put across the output and an inline fuse added.
Most of the time when these tantalums blow they take out a couple of ic's on the motherboard. If you are back in business, fine. If not, let me know and I can maybe help you out. They are cheap and easy to replace.

One other note of warning. The RA and DEC drives can get a little noisy in these things. A lot of people try to take them apart and lube them. It's easy to mess up the encoders doing that. If you aren't really comfortable with doing this, get someone experienced to do it.

Hope you are back in business.




Meade's wireless hand controller only worked with the LX200GPS scopes, not the LX200 Classic scopes. And it has been discontinued at any rate. It had way too many QC problems.

Tantalum capacitors are much-better than electrolytics in almost every application. Meade's mistake was in installing under-rated caps. Replacing the existing 16V-24V tantalums with 35V tantalums is the correct solution. Almost every single mf cap on any modern circuit board is a tantalum, not an electrolytic. Your cellphone, TV and car are full of tantalums.


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rimcrazy
sage


Reged: 03/03/12

Loc: Overgaard, AZ
Re: 12" LX200 classic with fuse problems new [Re: Christopher Erickson]
      #5648578 - 01/28/13 04:06 PM

I replaced all of the caps on my 10" LX200 classic myself. Not too big of a deal except the RA board. You can't remove it without cutting wires and there are quite a few. Stupid that they are soldered both into the board and bound into the motor assy at the other end. I ended up making connectors to put it all back together. I use 10uf 50V Tan. caps and changed my supply to a 15Vdc. I have a fair amount of weight on my scope so I did not want to go all the way down to 12V. I cut the max slew rate by about 1/3 so as to not overtax the motors.

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George D
Vendor
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Reged: 04/13/10

Loc: So Cal
Re: 12" LX200 classic with fuse problems new [Re: rimcrazy]
      #5654697 - 01/31/13 05:05 PM

Quote:

Tantalum capacitors are much-better than electrolytics in almost every application. Meade's mistake was in installing under-rated caps. Replacing the existing 16V-24V tantalums with 35V tantalums is the correct solution. Almost every single mf cap on any modern circuit board is a tantalum, not an electrolytic. Your cellphone, TV and car are full of tantalums.




Actually; The "best" component to use in any circuit is the one best suited for it's needs. In the case of tantalum caps versus electrolytics, it's a trade off in size, precision of rated capacitance, and cost, as well as potential failure modes and longevity.

Tanatalums tend to have a much more catastrophic failure mode (actual fire and flames occuring) versus that metal can of an electrolytic. Since the circuits in the Meade products are using the caps for power filtering, and not for critical timing circuits, I recommend and continue to replace these caps myself, with electrolytics instead of tantalums.


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ginnyj
newbie


Reged: 01/06/14

Re: 12" LX200 classic with fuse problems new [Re: altair1956]
      #6300101 - 01/08/14 01:43 PM

I'm glad I found this old post - my LX200 keypad just fried and I will be contacting him! Thanks for posting the info!

Ginny


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orion61

*****

Reged: 10/20/07

Loc: Birthplace James T Kirk
Re: 12" LX200 classic with fuse problems new [Re: ginnyj]
      #6300154 - 01/08/14 02:24 PM

Make sure you rpl the C2 cap in the handset as soon as you get it! I only use Military Grade, they are only a buck or so!
You can use as high a rating as you want as long as it is over
30, mine are 50, I have a bunch left over if you need some!
I also suggest you ONLY power it from 12V DC..
why bother taxing those old electronics!
Good Luck!


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wd8sbb
super member
*****

Reged: 08/26/12

Loc: Southwest Ohio
Re: 12" LX200 classic with fuse problems new [Re: orion61]
      #6302757 - 01/09/14 06:50 PM

If you feel that the Classic is good enough to repair, you may still be able to buy just the keypad membrane from Ron Sampson. He was selling them outright a couple years back.

Of course if you, or an interested friend, are not good with electronics, it may be much better to go with the autostar upgrade, or third party repair.

You cannot get through bootup without both the hand brick and base computer doing a handshake. So no it will not work via RS232 the way you say it is.

As for Meade not reparing the LX200 classic any more. Although I don't like that, you do have to remember that there are components on the circuit boards that are no longer manufactured and no old stock anywhere. It is tough to repair if you cannot get the parts.

As far as customer service, what is worse? Them saying send it in to us with you paying the freight. Then you get a call saying cannot repair at any price because there are no parts, what is your shipping billing number for us to ship it back. Or Meade saying cannot repair the machine, but we can offer you a new one.

Astronomy is not a mass consumer market that can drive manufacturing. And even if it were, the consumer electronic industry assumes 18 month obsolesence.

Edited by wd8sbb (01/09/14 07:17 PM)


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