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Dead LX200 GPS

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18 replies to this topic

#1 topbanana

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Posted 11 August 2021 - 05:27 AM

Hi all

 

I took my 8" LX200 GPS out of its box after several years, but was rather disappointed when it wouldn't power up.

 

In fact, the red LED does come on, and the handbox does briefly beep but that's it.  I made up an RS232 cable and I couldn't get anything from the main unit, which suggest the main board to me.

 

Are there any common faults or things that I could check?  I'm fairly handy with a soldering iron

 

Many thanks



#2 Scope2

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Posted 11 August 2021 - 07:50 AM

Hi , try replacing the small batteries located behind the computer control panel cover.

They can be accessed by removing the 4 small Allen screws on front face.

 

                                         Clear Skies.

 

                                               Pat.



#3 michael8554

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Posted 11 August 2021 - 09:02 AM

The button battery behind the front panel stores some of the GPS data, it won't help with your problem.

 

OzAndrewJ will have some ideas, his MyScope software will probably be involved.



#4 OzAndrewJ

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Posted 11 August 2021 - 03:40 PM

Gday topbanana

If you cannot see anything at all but the red panel light comes on,

it might be the LCD.

The fact the rs232 wouldnt connect is a bother tho.

 

Can you try booting in safeload mode ( ie press 999 on booting )

It has its own LCD code and might at least show something.

 

If not,and you still cant connect, then its sounding fatal.

Andrew Johansen Melbourne Australia



#5 topbanana

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Posted 13 August 2021 - 03:47 PM

Thanks chaps

 

I mashed the 9 key and something actually happened. In fact it gave me quite a fright!  The scope slewed right up, then down.  It continued to try slewing down well past the stop, so I switched it off.

 

So I think I must just have a faulty LCD. I'm assuming I did something wrong in my RS232 attempts.

 

What do you think I should try next?

 

Many thanks for your help with this!



#6 OzAndrewJ

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Posted 13 August 2021 - 04:22 PM

Gday Topbanana

 

Pressing the 999 on booting does not allow you to move the mount

it puts the mount into a closed routine where only several specific download commands

will work via the serial port.

If you cant use 999 to get into download mode and the mount moves by itself

something else is going on, and it doesnt sound good.

 

Re the rs232, the only way to confirm it is try with another mount.

If it works, then it is wired OK and the problem is in your mount.

 

Andrew Johansen Melbourne Australia



#7 topbanana

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Posted 13 August 2021 - 04:51 PM

Thanks Andrew

 

So I've tried 999 and then updating the firmware but it couldn't detect the scope. I'm pretty sure my RS232 setup is correct.

 

So would you be suspecting the mount or the handset in this situation?  I guess I could have a look at the main PCB for blown capacitors and the like.  I'm not ready to give up just yet since it slewed up the down, so at least part of it is alive!



#8 OzAndrewJ

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Posted 13 August 2021 - 04:57 PM

Gday Topbanana

The handset is a dumb terminal, that simply sends keydown and keyup events to the mount.

If you cannot connect to the mount in 999 mode and the handeset shows nothing,

there is very little you can do unless you have access to other parts

to do some A/B testing.

Also, in 999 mode, only the left rs232 port ( alongside the Hbx port ) is polled,

so you must use that port for any connection tests.

 

Andrew Johansen Melbourne Australia



#9 topbanana

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Posted 13 August 2021 - 05:05 PM

Thanks again Andrew

 

Are people still servicing and repairing these? I appreciate that they're quite old now. The sad thing is that this one is barely used, life got in the way!

 

Perhaps in the worst case I could use a more modern mount and keep the optics.


Edited by topbanana, 13 August 2021 - 05:05 PM.


#10 OzAndrewJ

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Posted 13 August 2021 - 05:16 PM

Gday Topbanana

I think the last tech who did that sort of work in the UK retired a year back.

That said, its sounding like the main board, and that is easily replaced by a user.

I dont know of any one who actively does board level work on the LX200GPS main boards

unless it is something simple.

Only problem is Meade is in takeover turmoil at present, and spares have dried up.

They are supposedly getting back into production but no one really knows

if/when spares will start.

The LX200GPS is still being sold and is a flagship mount, so my gut feel is they will

make spares, but who knows what the policy of the new owners will be

( as they have a no spares policy for their own lines )

 

Andrew Johansen Melbourne Australia



#11 Stanislaus

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Posted 21 August 2021 - 04:06 AM

Thanks again Andrew

 

Are people still servicing and repairing these? I appreciate that they're quite old now. The sad thing is that this one is barely used, life got in the way!

 

Perhaps in the worst case I could use a more modern mount and keep the optics.

There is someone down in Kent who ought to be able to sort you out. I think his name is Steve Collingwood and I understand he used to work for Telescope House repairing Meade equipment when they sold it. Try Google SCT telescopes.

 

Found it.

 

https://sctelescopes.com/


Edited by Stanislaus, 21 August 2021 - 04:12 AM.


#12 Bnny

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Posted 21 August 2021 - 01:29 PM

Help please......I am brand new to this community.  I know nothing about telescopes.  My wife and I have always been interested in the night sky and have wanted to buy a nice telescope to view the moon and close planets.  I do a lot of junking and found a used Meade LX 200 today at an estate sale.  This thing is still in the box and looks new.  It has 5 or 6 extra eyepieces etc.  I wanted to plug it in to see if it works but it does not have the 18 volt power cord.  The price is $1,200 marked down today to $600.  This sales ends today in 2 hours.  Should I buy this telescope?  or buy something new for a beginner?  I really don't care to buy it to make money.



#13 carolinaskies

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Posted 21 August 2021 - 03:27 PM

Help please......I am brand new to this community.  I know nothing about telescopes.  My wife and I have always been interested in the night sky and have wanted to buy a nice telescope to view the moon and close planets.  I do a lot of junking and found a used Meade LX 200 today at an estate sale.  This thing is still in the box and looks new.  It has 5 or 6 extra eyepieces etc.  I wanted to plug it in to see if it works but it does not have the 18 volt power cord.  The price is $1,200 marked down today to $600.  This sales ends today in 2 hours.  Should I buy this telescope?  or buy something new for a beginner?  I really don't care to buy it to make money.

It can be run off 12v... the plug is 5.5x 2.5 center positive. 
The price if it looks essentially brand new is good.  What size is the scope 8" 10" 12"?   If working it's a reasonable deal.  If non-working the OTA is worth $400 by itself.  



#14 Christopher Erickson

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Posted 24 August 2021 - 01:57 PM

When troubleshooting a fully-dead Meade LX200-GPS scope, ALWAYS try a new power supply before doing anything else.

 

A 12V jump start battery pack from Wal-Cos-Fred-Targ-Mart would be ideal.



#15 NearVision

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Posted 24 August 2021 - 03:58 PM

Actually the only thing worse than a jump start battery is a car battery because it's heavier and more expensive. While they will run a scope they are designed to give a very large current for a few seconds instead of a small current for hours. That's why deep-cycle batteries are recommended instead.

Again it won't hurt the mount or other equipment but you won't get anywhere near the same life out of the battery and need to replace it a lot sooner.



#16 rmollise

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Posted 24 August 2021 - 04:55 PM

Actually the only thing worse than a jump start battery is a car battery because it's heavier and more expensive. While they will run a scope they are designed to give a very large current for a few seconds instead of a small current for hours. That's why deep-cycle batteries are recommended instead.

Again it won't hurt the mount or other equipment but you won't get anywhere near the same life out of the battery and need to replace it a lot sooner.

 

 

The last jump start battery pack I had die on me lasted 11 years. And that's been my history with them. The secret? Charge them for 12 hours after each use. Charge them for 12 hours if not used over the course of a month. wink.gif


Edited by rmollise, 24 August 2021 - 04:55 PM.

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#17 NearVision

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Posted 24 August 2021 - 06:13 PM

And they may last for a while like Rod's. But they are designed to work as a short-term high current source and not long-term low current like our equipment needs. You can also set your mount on a pile of bricks instead of a tripod or pier and it will work. Just not as well as the tripod.

 

My point was to help someone make a better quality choice. In the long run, it may not matter which type of battery you use. I've known people that use "AA" batteries in their scopes and have for years without complaint. It's just not the best power source option for most people. There is a lot of information being passed around that is far less than the best. Talk to anyone that knows batteries and they'll tell you why a jump-start battery is less than optimal. NOTE: That most likely does not include the person behind the counter at walmart.



#18 Christopher Erickson

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Posted 03 September 2021 - 03:31 AM

We are talking about troubleshooting here, not regular field operations.

 

Actually the only thing worse than a jump start battery is a car battery because it's heavier and more expensive. While they will run a scope they are designed to give a very large current for a few seconds instead of a small current for hours. That's why deep-cycle batteries are recommended instead.

Again it won't hurt the mount or other equipment but you won't get anywhere near the same life out of the battery and need to replace it a lot sooner.



#19 MikeBY

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Posted 17 September 2021 - 10:04 AM

Help please......I am brand new to this community.  I know nothing about telescopes.  My wife and I have always been interested in the night sky and have wanted to buy a nice telescope to view the moon and close planets.  I do a lot of junking and found a used Meade LX 200 today at an estate sale.  This thing is still in the box and looks new.  It has 5 or 6 extra eyepieces etc.  I wanted to plug it in to see if it works but it does not have the 18 volt power cord.  The price is $1,200 marked down today to $600.  This sales ends today in 2 hours.  Should I buy this telescope?  or buy something new for a beginner?  I really don't care to buy it to make money.

Wondering if the OP actually bought this telescope? 




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