small problem with Gemini V1.05 brains

[h0ughy]

well i keep putting in new batteries only for the computer to loose the cmos settings after i turn it off. when i turn it on I can set the location with the GPS and the mount i manually set to titan50, it takes two goes but it remembers - but if i turn it off and wait 5 min it looses the lot. its becoming a PITA. I know its not the batteries i have been through 4 different packs of brand new energiser and duracell CR2032.

So what may be the problem?

[mithrandir]

David, are you sure the battery is located correctly and the clip is OK? See if holding the clip down while turning off and disconnecting power, waiting 5 mins and powering up makes any difference. If it does, try a metal shim on top of the battery.

One question. Are you using the hand piece or running it from Gemini.net? Gemini.net might be downloading a default config. You have to get it to save a valid config before letting it download on connect.

[h0ughy]

no using the handpiece - i have set gemini.net for my observatory so when i connect it it does write the location etc of the obs to the handcontroller, but in this case i did seat the battery. i will take some macro shots of it this evening.:question: to see if it looks fully seated

[wasyoungonce]

David

you have check the SRAM/RTC voltage, see here (http://gemini-2.com/faq.php#Q15), should be above 2.8V. You probably already know this but low voltage is the usual suspect.

I can speculate the causes but best to have a reading of the VSRAM first before rabbiting on.

[h0ughy]

but i have put in a brand new battery? No idea how i measure this without killing something - not my skill set (I have no skill set ;) )

[wasyoungonce]

Hi David

Check the battery clips are not distorted and losing contact. This can lose VSRAM etc. Other that that it really needs VSRAM measured to gauge the fault.

Other than a bad battery/battery clip, it could be a couple of things, mainly: bad Diode D1 (common fault); SRAM IC (another common fault); C8 (sometimes) or RTC IC (rare). Since D1 is a dual diode: one half feeds VBatt to SRAM/RTC cct when powered off.

+5V powers the other of D1 cct when switched on. This allows SRAM data to be stored by sensing the lower voltage, Vbatt, and come to life when it senses +5V (aka switched on). If you lose Vbatt/VSRAM then data will not be saved.

It's all to difficult to say with certainty what the issue is atm without measuring VSRAM. I have replaced SRAM IC's, D1's and RTC for similar symptoms (all different faults).

Do you have a friend who can wield an multimeter?

We all have skills...I for instance have no artistic talent :sadeyes:yet yearn for such!:lol:

[h0ughy]

yes artistic talent would be nice - missing from my gene pool:rofl:

so if it is one of the other things - where would i get them repaired now?

[wasyoungonce]

David...

I have a full list of Gemini 1 spares on Hand and have repaired ~a dozen units so far. I suspect D1 or SRAM IC...done a few of those.

I cannot say if Peter Ward is repairing Gemini's, you would have to ask him.

[allan gould]

David
I have recently had my Gemini handset repaired by Brendan.
Excellent service from him and I could not praise him more highly.
Knew exactly what was wrong from a description and fixed it promptly.
I would not hesitate to send my whole Gemini setup to him for evaluation and fixing.
Would I lie to you? :shrug: :D

Allan

[h0ughy]

yes i think i will do that:P I trust you as far as that Scargo will travel ;)

[h0ughy]

he did repair the switch on the module a few years back:thumbsup:

[wasyoungonce]

Hi David, PM sent.

I'm guessing this is the PCB version with the Slide switch (these switches were prone to some fails, although I have replaced on of the newer switches as well, quite odd!)....although it doesn't matter what type of PCB.

edit:
Many thanks Allan, I do appreciate the kind sentiments.

[h0ughy]

be in the post this afternoon

[wasyoungonce]

No Problems David. If you have GEMINI ASCOM.net profile for your system, you can send me, I can upload it prior to dispatch.

[h0ughy]

on its way express overnight post

[wasyoungonce]

Ok all fixed looking good just doing final tests, No need to go overboard with days of testing, all functions: Slew; Sidereal; park; RS232 & ST4 have been tested as ok.

Should dispatch late today but will notify.