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Hello Everyone
The Tale of the neglected G11.
I have had a G11 from around 2007, mounted on a concrete pier on my patio here in SE of the UK. It has the old type Gemini 4 Level 1 Controller [?]. A C9.25 and Tak Sky90 ride side by side on top.
For the past 5-7 years [possibly longer] the mount, controller and scopes have been covered up with just a plastic bag and a tarpaulin and never seen the light of day [or night].
What they have seen is years of rain, frost, sun and snow over the period of non-use.
Last week [week 11 of 'Lockdown' here in uk] encouraged by my son, I summoned up the courage to gingerly peel away the tarp etc.
I was more than pleasantly surprised and releaved to see little obvious outward signs of damage to the scopes or G11/Gemin Controller.
I plugged in the Gemini controller to a psu fully expecting either no response or at worst possibly a bang - what I actually got was a feeble bleep and some red dots on the HC - phew.
Internal inspection of the Gemini Controller showed no corrsion or signs of water ingress - it looked pristine. One new coin battery later and I had a working system and HC.
After some cleaning of the scopes optics, and various other electrical connections [RA/Dec Motors] and copious reading of the G11 and Gemin Manuals the big night came.
Some carefull levelling and polar realignment of the mount was carried out then finally a 'cold start' was conducted, just two alignment stars later and a few experimental gotos were performed - I appeared to have a fully working system after all these years of neglect - wow or 'gob-smacked' as we would say in the uk!
Excited and encouraged, on the following night I connected my DSLR camera to the Sky90, synchronised on Mizar before a tentative GoTo to M51. Took a 10 sec exposure - nothing.
Cranked up the ISO to 1600 and extended the exposure to 3 mins and as the camera's rear screen flikered into life there was the unmistakable spiral shape of the Whirlpool bang in the middle of the camera's screen, ok the stars were oddly shaped but an amazing result from equipment and electronics that had stood idle for all that time.
This little tale says a huge amount about the design, materials and production values of both G11 mount and its companion Gemini Controller - thank you Losmandy.
I will now set about more reading of the Manuals, possible clean and relube of the Mount and how to build a proper pointing model etc.
I attach [I hope] a recent image of the Moon just after first quarter [Sky90 Canon 5dMk4].
Thanks for listening.
Terry
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My advice
remove the main PCB and scrub with electronic cleaner spray and ¡°fitch brush¡±. Scrub off residue let dry put it back together.?
Sitting for do long will leave oxides firmed on it from air and moisture evaporation. ?These shoul DVD be cleaned off.?
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Brendan
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I, like Brenan, would do a through cleaning, and also gently clean any connectors.
Personally, I would have cleaned it before ever having applied power to it.
The fact it survived the deep sleep period speaks well for the mount, and your care when you stored it all those years ago.
I'm surprised everything did so well there in Old Blighty. But delighted it did.
I would imagine you are entering the better time of the year to observe and image.
Enjoy! And welcome back,
Great Moon Picture!
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SonnyE
(I suggest viewed in full screen)
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Brendan
You're right. Moisture and voltage lead to corrosion and dendrites. Corrosion "eats" the solder and voltage causes the metal ions to migrate forming conductive shorts called dendrites. Leaving residue reacts with moisture and continues the cycle. So use cleaning solutions that leave no residue themselves.
Chyck
-----Original Message----- From: Brendan Smith <brenatlilydale@...> To: Losmandy_users < [email protected]> Sent: Wed, Jun 3, 2020 05:31 AM Subject: Re: [Losmandy_users_io] My G11/Gemini Lives! My advice
remove the main PCB and scrub with electronic cleaner spray and ¡°fitch brush¡±. Scrub off residue let dry put it back together.?
Sitting for do long will leave oxides firmed on it from air and moisture evaporation. ?These shoul DVD be cleaned off.?
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Brendan
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Terry, The above advice is given with love but in reality may be misplaced. Do this in this order: First verify the firmware version EPROM in the Gemini system. You can see this when the Gemini wakes up or once booted go to MENU, scroll to SETUP scroll to CREDITS and? look for the words Level 4 v1.0.x. If you DO NOT see Level 4 v1.0.4 or 5 ORDER the latest version firmware EPROM from your UK Losmandy super fan david.partridge@...?and then wait for the EPROM to arrive before opening up the case.? Next carefully remove the Gemini 1 front cover and if it all seems clean and shiney here is where (if you needed the updated EPROM) you gently pry the old EPROM out of its socket and carefully install the updated version you got from David. Once the new EPROM is in place verify the system boots and you see the updated version on the display. If you feel compelled to spray stuff and clean the board just know that disturbing an ancient but working system is stupid. After a successful boot up power down and unplug everything and fiddle the cover back on and count your blessings.? ? -- Chip Louie - Chief Daydreamer Imagination Hardware
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On Wed, Jun 3, 2020 at 01:06 PM, Chip Louie wrote:
If you feel compelled to spray stuff and clean the board just know that disturbing an ancient but working system is stupid.
Spoken like one who has never had experience with electrical maintenance. And dismounting and remounting EPROMS is perfectly fine? Doesn't disturb anything? Very bad advice, Chip. once opened, the atmosphere is in the device. Condensation, although distilled water in and of itself, it mixes with any dust or contaminants, becomes a lethal mixture for the electronics. Hence, why things should be cleaned with approved electronic cleaner. But then, what do I know? I only have ~ 50 years maintaining some of the most sophisticated power systems on the planet. Pardon me, I'll go back to my Dunce cap in the corner. At least Brendan has some smarts. ? -- SonnyE (I suggest viewed in full screen)
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I understand what Chip is saying. ?Personally I¡¯d remove the socketed ICs and clean them and the sockets.?
i¡¯ve seen bad corrosion on the CPU pins and socket. ?So bad the CPU was toast.?
But the propensity, for a lay, of putting an IC back the wrong way is high. ?Depending upon the users. ?Some are very savvy.?
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Brendan
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Hi gang,
Lots of experience revealed in these discussions.
I find the CPU and EPROM pins to cold weld to their socket pins over the long time they have been in place in G1 units.
Removing these (if cold welded) from their sockets is possible but not easy.? The CPU is particularly hard to get out of its socket without the right tool.? If you don't have problems operating the G1, ... you might cause trouble trying to remove the CPU.??
(And all these devices are ESD sensitive.? You ideally need to have antistatic jacket and grounded wrist strap to handle the devices.? This problem is far worse in dry weather like cold winter where static builds up on (wool and other) clothing.)
So look for discoloration and corrosion first on both sides of the?motherboard.? If the board looks fine leave it alone.? If discolored, a swab with isopropyl alcohol usually works well. Look at the board in the hand controller l, and the connector socket pins also for rust or corrosion.??
The G1 units are not sealed at all. Air gets in easily through the areas surrounding the hand controller cable socket, and the open gaps between the RS232 port and the adjacent autoguider socket, etc on the front metal cover.? Insects sometimes crawl in and nest.? I have tried sealing those holes with a heavy felt.? Or just take the G1 in the house if the weather turns bad.
Have fun, and stay safe,
Michael
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I understand what Chip is saying.? Personally I¡¯d remove the socketed ICs and clean them and the sockets.?
i¡¯ve seen bad corrosion on the CPU pins and socket.? So bad the CPU was toast.?
But the propensity, for a lay, of putting an IC back the wrong way is high.? Depending upon the users.? Some are very savvy.?
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Brendan
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Sonny,
I have repaired more computers and mount electronics that laypeople tried to "clean" or "fix" than you can imagine. When I say the average person should leave well enough alone if the board components are clean and shiney it comes from many years of cleaning up after people who had no idea what they were doing even using "approved cleaners." That said this stuff is not rocket science but it does take some judgement, something most people don't seem to have when it comes to so many things.
Like for instance, you calling me out as never having had experience with electrical maintenance. It is 100% true I am not an electrical maintenance guy and likely never will be. But starting in the mid-70s I did mini and microcomputer peripheral circuit board design, mostly memory, disc, terminal and printer I/O and kernel I/O coding, component level repairs and field circuit board modifications. This is how I came to save so many botched computer and mount controller repairs done at home by enthusiastic but unqualified laypersons.?
As to your question "But then, what do I know?" I have no idea but I know that it is not thinking before pressing send.?
???
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Chip Louie - Chief Daydreamer Imagination Hardware
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My first computer I worked with/on was a Univac 9000 in the Mid 1970's.
For all it's gigantic needs, it was little more than a giant reel to reel recorder, with racks and racks of tape reels.
Beginning in the late 1980's, I began using a home PC, and in the early 1990's I began building my own. Which as you should know was little more than putting together components.
I spent 17 years working at the Southern Terminus of the Pacific Intertie Project.
So I am very well versed in all facets of electrical maintenance and troubleshooting.
I use to teach folks how to do it as well as doing it, trouble shooting, and failure analysis.
For you to call Brendan and I stupid is why I called you out.
Normally, I have been letting your less than accurate advice slide.
But you've shown just how small your real experience truly is.
I'll now go back to ignoring you, until you again offer more bad advice. At which point I will again engage.
You should have included the fact that pulling EPROM's also requires the use of EPROM handling pullers.
But hey, I know bad advice when I smell it.
You have a lovely day!
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SonnyE
(I suggest viewed in full screen)
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Jeez Guys...
I normally enjoy the friendly banter between you guys, but is this really how you want Terry to perceive some of the sharper minds on this forum ?
You know, I'm just another nut loose behind the keyboard, but please, lets get back to the spirit of why we are here in the first place...
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I have to agree with Astronut here.
And Terry, WOW man that is so cool :-D
I was telling your story to a friend of mine and he was so impressed! And with the weather you have in the UK it makes it even more impressive!
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For those following the thread here is something to think about.?
If?something is working fine and as I had originally qualified, the insides are shiny and clean, why mess with it? SMD boards are harder to fix than through holes boards even with a hot air SMD repair station. When people spray and scrub to clean boards they sometimes can inadvertently loosen or even remove smaller components. For most people reading here that board instantly became E-waste because unless you know what you did it is likely cheaper to buy a used one from CN or AMart than to pay a qualified tech to identify, acquire the component, replace and test the board.?
As far as a special tool goes for pulling out an old style EPROM from a socket on a sparsely populated board there is plenty of room to use a standard 1/8" x 2.5"-3"" flat blade screwdriver gently working by prying both ends. People have been doing it this way for 50 years or so. Or if you feel compelled to use an approved spray or chip puller buy one from Amazon for $10-$25 to use once, I have Wiha brand precision drivers, they're nice.?
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Chip Louie - Chief Daydreamer Imagination Hardware
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Chip, I agree on not cleaning. In my experience, I have come to a rule of thumb: If it works don't touch it.
Hardware wise I know for a fact that if you have badly corroded lanes on a PCB you might destroy them while attempting to clean them.
Sonny, I do agree that water exposition could induce shortages and fry a few chips. I might be wrong but to me corrosion wise, worst case scenario is that it does not work.
So as it works fine I wouldn't do anything else than enjoying gathering light.
However, the initial point of this post was about Terry that got a Losmandy and scopes to work almost out of the box after having them staying 5-7 years out in the rainy British weather under a tarp.
He didn't ask for advise or reported issues. He only shared his success in his revival endeavor.
That is truly amazing! We should be speaking about that not arguing about what advise is the best ;-)
Congrats to Scott for putting such a product out there!
And congrats to Terry to get all his gear up and running, and the very nice lunar image!
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Many thanks to all [Michael, Chip, SonnyE, Brendan and Chyck] who commented on and offered advice on my resurrected G11. I¡¯ll be following up on upgrading the firmware EPROM with David P here in the uk. Thanks again. ? Terry ? ?
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Hi Terry,
Going that route of replacing the EPROM, here are some notes and advise:
You will not need to pull out the battery, just leave it in place. That will hold the SRAM data of location Latitude and Longitude and mount type in place. The RTC chip will continue to track the UTC time.
Do not wear any static producing clothing...nothing wool! Disconnect the power cord, remove the front metal cover (6 small screws with round Allen head sockets).? Then discharge yourself by touching any of the board corner hex metal spacers that hold up the front metal cover.??
For removing the EPROM, no need to buy any IC tools, but....I find a simple metal hook tool to work well. You use it to gently pry up the EPROM chip a small amount from each end. It is a metal hook tool you can buy at auto parts supply stores.? It is more difficult to use a flat screwdriver, due to other chips nearby.? Save the old EPROM chip... it can be re-used if the new one goes bad, and the old one can be erased and reprogrammed if?it is in a ceramic package.??
It is common to have the old pins get bent getting it out of the existing mounting holes.? The leads are plated copper, and can be straightened out, but too much bending will break them.??
You will notice that the metal pins of the EPROM are not really in a socket, but instead in little metal individual pins with small holes on the board topside.? They have no spring clips like a true IC socket.? It is therefore tricky to get the new EPROM pins into all these holes simultaneously.? So instead, try this:
First, gently bend the new EPROM leads to be vertically downward, and to be in line, at the spacing of the board socket pins.
Then place the EPROM in position.? Note the little indentation on one end of the new chip, and see the same indent marked on the board printing.? Make sure those are matched up.??
Starting at one end of the chip slightly tilted, use a fine tweezer to nudge each pin into place in it's socket pin.? When all the pins are starting to fit, gently press the chip in the rest of the way.??
Power on your G1 and look at the display. You should see all correct information and the new:? "level 4 version 1.05" displayed.? That's it...done.
Stay well, Michael
Many thanks to all [Michael, Chip, SonnyE, Brendan and Chyck] who commented on and offered advice on my resurrected G11. I¡¯ll be following up on upgrading the firmware EPROM with David P here in the uk. Thanks again. ? Terry ? ?
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Chip Louie
Michael Herman