Re: RTC issue with Gemini 1
Hi Franck
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Here¡¯s a few possibilities:
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1: The RTC put in was probably 2nd hand or at worst ¡°counterfeit¡±. ? The only sources of these can be good or ¡..dreadful! ? Sometimes it¡¯s a lottery. ?If you¡¯re other Gemini 1 has this IC in a socket. ?Try swap them. ?Pls use ESD precautions.?
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2:SRAM does have locations for RTC data the SRAM may be damaged. ?This is a high possibility I have seen similar before. ?Loses some data but not other!
3: The CPU (and HC display(s)) converts or determines HC data to Characters displayed. ? ?It¡¯s possibly a bad CPU. ? ?Swapping CPUs ¡again observe ESD precautions. ? You need a PLCC IC puller. ?
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4: ?Lastly the HC displays interpret data streams and with inbuilt controller helps convert this to characters. ?Easily checked. ? ?Swap them¡.?
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The above, in order are all possibilities of fixing the issue starting at most probable to least.?
It¡¯s a little hard to say. ?Since the RTC and CPU are easily changeable, one usually goes for easiest possible fix first. ? ?
But¡..I kinda get the impression it¡¯s SRAM!
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Anyway FWIW, definitely try plug-in swappable ICs first before touching SRAM. ?You can ohm out SRAM and RTC pins to each other and gnd to check for any glaring abnormalities.?
FWIW cheers, get back on how you go or if you need more assistance.?
cheers
--
Brendan
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Hello all,
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I'm the proud new owner of an old G11? from 1995running Gemini 1. To get it working almost like new, I had to re-grease it, replace the polar scope, and decided to reduce the default motor speed to 600 to preserve what's left of them. I've taken a few months to validate the setup using either the controller or a small Mele computer running NINA, PHD2, stellarium and now FireCapture for planetary imaging. It all works like a charm with decent guiding for my C11 or CFF 105mm refractor, including meridian flips¡ªGREAT!
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As a precautionary backup, I got my hands on a second Gemini 1 with the same old motors at a good price. However, I'm still trying to get this one to work, as I've had issues with the RTC. I replaced the CR2354 battery with a new one that reads 3.3V. The location, mount type, and other settings all work well and remain in memory with no issues. However, the RTC wasn't functioning correctly. Initially, it displayed an RTC error and erratic time displays with symbols like "?" and "#", along with numbers. I decided to replace the RTC63421A with a new one.
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Now it's better: I can set the correct time, but the RTC doesn¡¯t run consistently. Sometimes it stops, sometimes it blocks the controller, at best it runs at about 1/3 the normal speed (i.e., seconds only update every 3 seconds). I¡¯ve attached a photo of the main board. Nothing looks fried to me, so I¡¯m stuck. Any ideas about what might be happening or how I could troubleshoot further?
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Many thanks, Franck
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Re: Looking for cable source - Try Cat8 cables
The connector IDC types (Insulation Displacement Contact) are for solid conductor and stranded conductor.? One can find ¡°flat¡± wire ¨C easier to crimp - ?but I have had poor results with long ¡°flat wire¡± cables. -Will ?
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From: [email protected] <[email protected]> On Behalf Of Brendan via groups.io
Sent: Sunday, November 10, 2024 3:33 AM
To: [email protected]
Subject: Re: [Gemini_users_io] Looking for cable source - Try Cat8 cables? You can buy flat single core of multi core RJ cable. ? Also a crimp tool and RJ45 terminal ends¡.crimp your own. ?Or try repairers to make them. ? Be aware some RJ45 connectors are for solid core some for multi core. ? I guess it¡¯s the crimp ¡°teeth¡± difference. ? Or something. ?
I¡¯ve made RJ to DIN cables for owners and plenty of RJ cables. ?Either RS232/ST4 & RJ 45. Not hard.?
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Re: Looking for cable source - Try Cat8 cables
Gotta say if you are happy with the shorter cables you have. ? ?No ¡°glitching¡± then keep what works for you
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cheers
--
Brendan
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Re: Looking for cable source - Try Cat8 cables
You can buy flat single core of multi core RJ cable. ? Also a crimp tool and RJ45 terminal ends¡.crimp your own. ?Or try repairers to make them. ?
Be aware some RJ45 connectors are for solid core some for multi core. ? I guess it¡¯s the crimp ¡°teeth¡± difference. ? Or something. ?
I¡¯ve made RJ to DIN cables for owners and plenty of RJ cables. ?Either RS232/ST4 & RJ 45. Not hard.?
cheers. ?FWIW
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--
Brendan
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Re: Looking for cable source - Try Cat8 cables
I agree. I would think a 15 foot long motor cable would be worst case, so getting 3 foot ones should be better.
I have run the cat8 3 footers on the bench for 8~9 hours a day, and many days now w/o seeing the glitch. (to be fair, this is no load)
But as you said, its not the technical proper way.
So, what 8 conductor flat cable do i buy to make the proper cables?
What awg is the proper wire size?
TIA
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Re: Problem with G11 and Gemini L4 V1.04 - Older version
Good call Paul, well done!
Cheers
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Brendan
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Re: Problem with G11 and Gemini L4 V1.04 - Older version
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IME with Gemini 1 controllers you really need to replace the battery at least once a year even if you don't think so.? My advice is to ALWAYS have a small toolkit with a couple of spare coin cells in your Gemini-1 case.? If not for your mount other people with Gemini-1s who are not so well prepared.? You will become very popular with fellow Gemini-1 owners.? ? ?
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--
Chip Louie Chief Daydreamer Imagination Hardware?
? ?Astrospheric - South Pasadena?
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Re: Problem with G11 and Gemini L4 V1.04 - Older version
Hi,
i replaced the CR2032 battery and what shoud i say ??
THANK YOU ALL FOR YOUR POSTS !?
This was the reason for my gemini fault. After i replaced the battery, the mount runs perfect and everything is fine.
He slews, centered and finished.?
Now, he works on a part of a mosaic of M31.
Thank you very much for your help !!
Wish you a great evening and clear skies
´¡²Ô»å°ù¨¦
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Re: Problem with G11 and Gemini L4 V1.04 - Older version
On Mon, Nov 4, 2024 at 06:27 AM, <Stargazer32584@...> wrote:
Later, i will replace the 2032 battery.
Just keep the battery out for a minute before replacing. That's needed for the capacitors to fully discharge, allowing all the settings to be completely wiped from memory resulting in a full reset.
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Re: Problem with G11 and Gemini L4 V1.04 - Older version
Hi Guys,
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thanks a lot for your answers !
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Later, i will replace the 2032 battery.
I don't use the AG-port. I have an Starlight AO and only use the RS232 Port. But before i change the battery, i will disconnect the RS232 cable.
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@Rene: No. There is no message in the display on start-up. Everything is fine and normal.?
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Thanks a lot for your support!
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Re: Problem with G11 and Gemini L4 V1.04 - Older version
You've checked the cables already, this is good,
since every little spurious signal that could be a button press
(Deluxe or classical HC and AG) would be interpreted as an
interruption of a Goto operation. Disconnect
an autoguider. Please check the sockets
carefully. Is there a message displayed at startup regarding AG or
HC?
¸é±ð²Ô¨¦
Am 03.11.24 um 20:42 schrieb
Stargazer32584 via groups.io:
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Hello guys,
my Gemini System runs about 24 years without a greater problem.
But now, i have a problem with this system.
If i want to slew to an object, the system make a slew, goes
into centering mode but does not stop. The gemini stay in
this mode until i press the right-arrow button on the controler
to interrupt the centering. If i want to slew to another
objekt, the controler print the message *Interupted" in the
display. There is no possibility to slew to any other object.
The system repeat the "Interupt" message on every try to slew.
Also from a pc given object, from N.I.N.A., for example.
What problem could it be with the controler ?
I check the following things:
1. Complete reboot of the gemini system. - No effect
2. Disconnect from the pc and try to slew - No effect
3. Disconnect al cables and checked for dirt - Everything seems
to be okay.
Thanks a lot for your support !!?
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Re: Problem with G11 and Gemini L4 V1.04 - Older version
Actually Paul is correct...check basics first...new battery re-input data and limits
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retry it...I guess you can emulate it during daytime to slew to stars that are above horizon during the day...using a plainsphere
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cheers
--
Brendan
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Re: Problem with G11 and Gemini L4 V1.04 - Older version
I have actually seen this before on my G1 a few times, many years ago. ? It went away, so, I thought it a firmware glitch. ??
But it¡¯s possible it¡¯s not reading encoder pulses properly so keeps moving but I cannot answer "why in centring"? ?? Can you change the centring rate to see if this changes?
All I can offer at this time is to ask is it happening in Ra or DEC or both axes? ? It¡¯s possible an EEPROM issue or encoder PLD readers on main board that reads motor encoder pulses! ? These had a programmed life ~15/20 years plus (according to datasheets) but, the their program input retention was not limitless in time due due to ¡well, I¡¯m not sure decay in gate programming?.?
But these can be changed or re-programmed. I've never tried to program one in situ I have removed them programmed a new one put it in. ? That was to fix drive encoder reading issues and on G1s and these are known failure point for many reasons.?
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Whether this is your issue ¡I cannot say but, I suspect a sidereal rate check could determine the issue. ? On a G11 the Ra motor axes rotated at 9.5737s per Revolution. ? What you can do is take out Ra motor set it up on a desk, put a pointer on the motor pinion and time it for 10 revolutions as it passes a marker¡that¡¯ll be enough to check it.?
I say Ra because it¡¯s used the most compared to DEC axes PLD.?
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But I¡¯m only guessing here I mean it could be stiction of the axes (like friction)..... I just don¡¯t know!. ?Oh if you have Varistors Rv1/2/3/4 on the main board measure them both ways with an ohm meter (power off) they can cause encoder pulse degradation. ?Removing them fixes this. ?? See image on my google drive
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Lastly what ver EEPROM do you have?
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cheers..ill await your reply.?? I'm sure Paul has seen or heard of this!
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--
Brendan
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Re: Problem with G11 and Gemini L4 V1.04 - Older version
Hi ?,
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I'd start by resetting Gemini completely by taking out the 3v battery for a minute or two, and then replacing it with a new, fresh one. **Interrupted** message usually indicates that Gemini thinks it can't reach the object without violating safety limits. This, and the other issues could easily be caused by corrupted settings in Gemini.?
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Regards,
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?-Paul
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On Sun, Nov 3, 2024 at 02:44 PM, <Stargazer32584@...> wrote:
Hello guys,
my Gemini System runs about 24 years without a greater problem. But now, i have a problem with this system.
If i want to slew to an object, the system make a slew, goes into centering mode but does not stop. The gemini stay in
this mode until i press the right-arrow button on the controler to interrupt the centering. If i want to slew to another
objekt, the controler print the message *Interupted" in the display. There is no possibility to slew to any other object.
The system repeat the "Interupt" message on every try to slew. Also from a pc given object, from N.I.N.A., for example.
What problem could it be with the controler ?
I check the following things:
1. Complete reboot of the gemini system. - No effect
2. Disconnect from the pc and try to slew - No effect
3. Disconnect al cables and checked for dirt - Everything seems to be okay.
Thanks a lot for your support !!?
|
Problem with G11 and Gemini L4 V1.04 - Older version
Hello guys,
my Gemini System runs about 24 years without a greater problem. But now, i have a problem with this system.
If i want to slew to an object, the system make a slew, goes into centering mode but does not stop. The gemini stay in
this mode until i press the right-arrow button on the controler to interrupt the centering. If i want to slew to another
objekt, the controler print the message *Interupted" in the display. There is no possibility to slew to any other object.
The system repeat the "Interupt" message on every try to slew. Also from a pc given object, from N.I.N.A., for example.
What problem could it be with the controler ?
I check the following things:
1. Complete reboot of the gemini system. - No effect
2. Disconnect from the pc and try to slew - No effect
3. Disconnect al cables and checked for dirt - Everything seems to be okay.
Thanks a lot for your support !!?
|
Re: Purchasing a G11 with last version of the Gemini-1 controller
Everything looks in good Nick polar scope,CKS clutch knobs and the 127 looks good?
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yes older motors but they look in good nick
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Brendan
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Re: Purchasing a G11 with last version of the Gemini-1 controller
Thank you for the links.
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In Photos, I just created the folder "Tom Losmandy G11 Photos" and within this folder are the two seller provided photos. The motors appear to be old discontinued standard motor.
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Thanks again,
Tom
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Re: Purchasing a G11 with last version of the Gemini-1 controller
Tom you¡¯re good, Paul answered better than I could. ?He¡¯s a wealth of knowledge.?
Take pics ¡.we can analyse them. Check axes are smooth and clutches engage but allow slip. ?Try to skim the G1 manual ?as there are HC shortcuts but basically it¡¯s just diamond buttons to move or select or scroll menu selections
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Menu and down or up button allows scroll thru various menu settings. ?Using the right arrow to select a setting or up down to enter or change time, location lat/long. Etc
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Gemini 1 uses a ¡°different utc date time code¡± in the system see Rene¡¯s site for how to enter current Gemini UTC DTG
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These mounts were made to last more than one life time. ? Also all parts are available (with plenty of factory upgrade paths) and they are easily fixable if something goes wrong.?
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Enjoy there are so many users here and a great forum to learn from ? Don¡¯t forget each forum has files and databases so you can search for particular nuts, screws. ?Losmandy sell them anyway.?
With any luck your mount will have the Hight a torque or maxon motors.?
https://gemini-2.com/Losmandy-motors.html
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Don¡¯t be afraid to ask questions. ?You might find users near you that will advance your knowledge in leaps and bounds.
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When you get into computer control using Gemini ASCOM ten it open a whole new world of possibilities ? ?Again Paul is the fountain of knowledge on this.?
/g/Gemini_ASCOM_Driver
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cheers¡good luck.?
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Brendan
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Re: Purchasing a G11 with last version of the Gemini-1 controller
Thanks for the help. Cross posted - I was not sure if my post got through here, being a 10 minute old user.
Regards?
Tom
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@fvitale
wforacer.rm
Chip Louie
Paul Kanevsky