Enter UTC date time in this format

Hi Michael,

As always the best advice!? The way the data has to be entered is routinely entered with American assumption that the notation is USA style. Your advice as always is read the manual.?

--

Chip Louie Chief Daydreamer Imagination Hardware?

? ?Astropheric Weather for Imagers - Click on my sig!

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Luke,

Probably too little information to make a diagnosis?

Maybe check and replace battery reset SRAM and re-input settings. ?Start over again?
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Brendan

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On Fri, Apr 29, 2022 at 06:47 PM, Kevin Simpson wrote:

• With the Losmandy cable firmly planted in the female socket, I've attempted to measure voltage against the pins on the Gemini end of the cable, and nothing registers. ? The male plug doesn't sit super nicely in the female dongle, but no amount of manipulation and fiddling causes the light on the Gemini to light indicating power delivery.

Kevin, this sounds like your cable is bad. Can you use your voltmeter on the Gemini-side of the cable, with the cable unplugged from Gemini to see if there's 12v across either of the 12-18v pins and ground? If not, you'll need a new cable or fix this one. Usually a simple solder joint may have broken at the connector, easy enough to check and solder back. Sometimes the cable gets stressed or bent in a way that tears it in the middle, but that's less likely.


If you do get 12v at the Gemini-side of the cable, you'll want to use the voltmeter to check for internal blown fuses/diodes and the power switch, which is a bit more tricky and Brendan or others here can guide you through the steps.

On Sat, Apr 30, 2022 at 02:04 PM, Kevin Simpson wrote:

Hi...wondering if a couple of these replies are actually for a different thread?

Moved this into a separate topic from?Recently Acquired G11 with Gemini 1: Can't power up the Gemini

Regards,

? ? -Paul

Hi...wondering if a couple of these replies are actually for a different thread?

Encoders can go bad by themselves but usually someone plugged it in wrong putting motor drive to encoder line killing it. ?Easy enough to replace cut the legs log off old body and disc together desolder cut legs but applying snd pull them out. Clean pads refit ensure crucifer didv is fitted at same time?

Or desolder gun.?

Yes sounds as if encoder PLD IC is Also bad ?check resistors near input pins to 5 V.?

Do replace it with a flashed 16CV8 BQL low stdby IC ? the code we have works with these I’m not sure on 18CV8s BQL ICs

You can also swap the PIC 42 ICs tactics dec snd visa versa. ?These rarely go bad. Test by replace.?

You can swap ra to dec ICs. Start with a known good parts cable motor snd theft from there.?

Thd H bridge ?had small ceramics to reduce noise they rarely go bad as well as the main motor drive rail Electros?

See how vu this goes one axes at a time?

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Brendan

Oh make you can make up a pwr tester to see if pwr is arriving at the Gemini sockets. ?Just a resistor snd LED?in series.
?
Plug this into the spare pwr socket (positive pins lhs as looking at the pwr socket, neg on RH pins looking at socket)

Let’s say a 1.5 v vdrop led @ 12VDC leaves 10.5VDC for the resistor to drop so let’s say 20 ma LED, (a guess) I = V/R thus R = V/I = 10.5/.020 = 525 ohms resistor let’s say go up to 580 ohms preferred value. Power = EI = 10.5 x .002 = .02W or 1/4 watts.?

So Solder a std leg resistor in series with a LED ensure you get the LED leg the correct position positive to positive of the Gemini socket (actually doesn’t matter if it won’t work one way it will work the other ).?

Pug it in across neg and positive pins of spare pwr socket plug in pwr to other socket it should light up straight away as it’s sending power before it goes to the fuse and schottky diode?

look you can do this with a multimeter but sometimes little tools like this hep visualise it better. This will tell you if power is arriving at the Gemini. ?If it’s dim (at the LED) maybe power is being lost. It should be nice’n bright.?

FWIW. ?I’d do it as it’s an easy tool

Yes I have seen bad power leads. ?Sometimes over current melts the internal plug fuse holder spring do it no longer forces the spring against the fuse. ?Take apart the holder to test this.?

I saw this happen at 4 amps when load testing using a cigarette plug. Anderson are better bit it doesn’t mean the wire at the other end (plug) isn’t broken.?

FWIW.?
--
Brendan

Damn posted before I finished. ?Try these, get back I don’t have my lappy to post power distribution diagram but will get it tomorrow. ?(In hospital again)?

cheers

--
Brendan

Hi Kevin I agree it look peer isn’t arriving at the gemini

if you plug it in to the power socket on the Gemini you can measure the spare power socket as they are in parallel. ?The 2 left pins gnd the 2 right pins power (opposite to what Michael said as you are now looking at the plug pins from the rear. ?

Measure this….power ok? ?If not ohm out the cable as said.?

If peer ok check main switch. ?Is it a slide switch or rocker switch. ?The slide switches can gum up and fail the rockers can as well. You can take apart the slide switch carefully and clean it inside. Not the rocker sw.?

Also check the fuse F1 (5Amp SMD) and Diode D1 (schottky) for continuity and v drop across them. ?They are in cct before the main switch.?

Here is a link to the that may help in faultfinding lots of links.?
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Brendan

Welcome to the group Kevin.?
Your power supply for the Dob running 12v should work.? Since you have a voltmeter it probably has an Ohms (resistance) setting or a diode test setting on it that will beep for continuity testing.?
The center pin of the cigarette adapter should be connected to the two pins on the right looking at the connector in the? orientation in this picture.?

Hello! ? I am new to these boards from the Bay Area of California, having recently purchased the entire collection of an accomplished astrophotographer including a beautiful Takahashi refractor, a Celestron C11 carbon fiber body, a wonderful set of Televue eyepieces, and my first ever equatorial mount, a G11 with Gemini 1. ?All of this is in excellent apparent condition, beautifully and lovingly cared for, but untouched for about 12 years. ?Right now I'm stymied trying to get the Gemini 1 component fired up so I can connect it to the G11 and then mount one of the scopes and test the whole rig for visual.

Since I have not yet made my first forays into AP, I am rigging everything first for visual so I can learn these two scopes and also the vagaries of EQ mounts. ?I've resolved almost all the mysteries with the G11.

On the Gemini, nothing I do will light the power indicator light on the unit.

A few background details:

• The rig came with a big Kendrick lead-acid style power box, dead as a doorknob after 11 or 12 years it seems. ? I will be using my rig almost exclusively away from home at a nearby park without access to AC power, so I'll either need to replace the internal battery inside the Kendrick, or find another practical power supply.
• The cable from the Gemini to the Kendrick has a 4pin Din at the Gemini end and a cigarette lighter male plug on the power source end. That cable was replaced by Losmandy exactly 1 year ago, documented by the original owner's daughter who sold me the collection, and has never been used. ?I have checked the fuse in the cigarette lighter end and it appears pristine; the filament is intact and there is no black smudge of a blown fuse. ?I have attempted to connect the cable to an Orion 12v 155wh Dynamo Pro Lithium power tank which runs my 10" GoTo Dob. ?I understand that 12v is at the low end of the amount of power needed by the Gemini and G11? ? That power tank has a dongle with a female socket and power output is right at 12v as measured with a voltmeter with needle style probes, red and black. ?The Gemini does not light up. ?I have replaced the 2032 battery in the Gemini unit in the past few days, and unsurprisingly this didn't make any difference. ?
• With the Losmandy cable firmly planted in the female socket, I've attempted to measure voltage against the pins on the Gemini end of the cable, and nothing registers. ? The male plug doesn't sit super nicely in the female dongle, but no amount of manipulation and fiddling causes the light on the Gemini to light indicating power delivery.

So, I'm trying to figure out what direction to trouble shoot: ?

• I have a dead DC power unit, of course, so I could replace the internal lead acid battery for about 150 bucks from Kendrick. ? But I still wouldn't know if the cable was bad until I'd gone that route. ?If there is a more modern, adequate rechargeable battery solution for this that will run the G11/Gemini I, I'd love to hear about it; I'll have to get the appropriate type of cable with it to feed power to the Gemini.
• Losmandy doesn't appear to sell the Gemini cable; I could swap out with a new cable to see if that's the problem, but special ordering or even attempting to make something (I'm not exactly a shop wiz) seems like a potential wild goose chase.
• Should I expect the Orion 12v to power the Gemini box, not attached to the G11?
• Is there some other way to check that the Gemini box is even functional? ?Keeping in mind that I'll be learning EQ mounts, strongly prefer a type of go-to system (I'm at an age where speed to results is important to me), should I even be messing with trying to revive the Gemini 1 and go with some other solution to controlling the G11 once I've got it rigged up and mechanically operating? ?I have a steep learning curve with EQ setup, alignment, etc. before I dive into AP somewhere in a year or so.

For background, I've always been astro-fascinated but only bought my first scope, an Orion 10" GoTo, about 2 years ago at the beginning of the pandemic. ?I spend as much as 3 nights a week out with that; I also bought a Unsitellar eVscope 2 as a good counterpart to the Dob for the outreach that I really enjoy and to share some images casually with far flung family and friends or small groups when we take some time at night to enjoy DSOs along with the beautiful lunar, planetary, and star cluster objects so well captured in the Dob. ?I don't consider the Unistellar to be a true AP rig, but it has begun to teach me some basic ideas about AP that will pay some dividends as I get into AP at some point with my new equipment.

Thanks in advance for reading this saga and for any thoughts you might have.

Best,

Kevin