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12" LX200 classic with fuse problems

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#26 Christopher Erickson

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Posted 07 January 2013 - 12:34 AM

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

#27 scotty693

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Posted 07 January 2013 - 04:30 PM

any solutions based in the UK , out there ?

#28 Christopher Erickson

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Posted 07 January 2013 - 04:48 PM

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.

#29 neotesla

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Posted 07 January 2013 - 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

#30 orion61

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Posted 07 January 2013 - 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

#31 scotty693

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Posted 08 January 2013 - 12:23 PM

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

#32 Mike Boessen

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Posted 26 January 2013 - 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.

#33 Christopher Erickson

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Posted 27 January 2013 - 10:38 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.


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.

#34 rimcrazy

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Posted 28 January 2013 - 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.

#35 George D

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Posted 31 January 2013 - 05:05 PM

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.

#36 ginnyj

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Posted 08 January 2014 - 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

#37 orion61

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Posted 08 January 2014 - 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!

#38 wd8sbb

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Posted 09 January 2014 - 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.






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