help - ST4 relays and buttons?

[h0ughy]

I have just been informed that my ST4 that I have just sold has a fauty relay/and or button:help: . Apart from having no idea that this was this way, its too late for me to chase up the original owner that stiffed me. Might explain why I had no luck using it thinking that it was me not doing something right.:mad2:


Is there anyone who could look at his unit with a possibility to repairing it or will it have to go over to the US to get fixed or I junk it?:sadeyes:

[montewilson]

They should be the same as the STV in which case you have nothing to worry about. I think they are off the shelf at Jaycar.

Let me find out and add another post soon. At worst I have quite a few and I would be happy to send you some - gratis.
All this is assuming they are the same but I think they probably would be.

Back soon!

[montewilson]

Here is what I found. If this is what they have inside you are out of the woods. If not show me one and I will see what I can do. Go to www.jaycar.com.au (http://www.jaycar.com.au) and put in relay in the search box. You will have to find out what the working voltage is for the ST-4. Its probably 5v. There are 5v models too. Don't forget you may require a diode in the circiut to supress charges that can weld the tiny contacts in these relays shut. I had this problem years ago and I lost months trying to find it. Good luck.


12V SPST DIL Reed Relay

They will fit into a 14 pin IC socket, are highly sensitive and can be driven by TTL, etc. SPST normally open. Nominal Voltage: 12VCoil Resistance: 1000ohms Must Op: 9.00VDC Must Release: 0.8VDCCoil Rated Current: 12mA Contact Voltage: 25max

QTY
1+$2.25
10+$1.85
25+$1.65

[h0ughy]

yep its all dutch to me? have to wait until I get the unit back Monte. The worst thing is that the original owner said that the unit had been refurbished and updated. on trust I believed him, not doubting the facts because quote simply I had no idea how the unit worked, I think Paul can attest to that at last years duckadang. I couldn't work out how the unit worked (IQ less than normal) and not getting my polar aligning right I blamed it on that. I only tried a second time last year to use it and once again I blamed my polar aligning thinking I stuffed up setting it up. So naturally I thought it was me and opted for a easier outcome, look at something else. Now knowing that there was actually a problem with the unit, maybe I didn't stuff things up and it was the ST4 all along.

Geez I can count the number of times I have been imaging on one hand in the last 12 months, and every time I thought that without setting this up in a observatory I put it in the too hard basket and went without, which then prompted my idea to sell what I am not using. I hope this can be a phoenix and rise from the ashes?

[montewilson]

Don't sweat it. Given that the unit is 80s technology I doubt we will find anything particularly exotic inside that can't be replaced. I did a bit more searching but didn't find a picture of the gizzards.

My guess is that a relay has failed as it is an actual moving part and they fail.

Get the lid of it when you get it and see if you can see any relays. They could even be tradional fat ones with a clear casing. Even if the exact unit isn't available it is such a simple task a suitable replacement should be easy to find. Take some pictures and I will try to identify where the relays are.

I found a few references to people changing relays in the ST-4 but they are old APML posts and didn't elaborate.

Hear from you soon

[meade expert]

Any luck with the repair?

[montewilson]

Not yet. I'm waiting to Houghy to get it and find out what's inside. Until then, I can't do much more than speculate.

[h0ughy]

OK Gentle fiends, After Bassnut graciously looked at the unit it turned out to be the relay. It was half out of the socket and not making contact. It would be prudent to assume that it suffered a jolt or drop that jostled the relay out of the IC socket it was in. I get the unit back on Monday. the other relays were loose as well so he repaired them by re seating them and using some silicone to help keep them in. For future reference I will take the cover off when I get it back and take a photo of the board and relays and post that. So fingers crossed its fixed.

[gbeal]

I agree Huff. Don't sweat. I got a near new ST2000 from the US, only to find it started to falter when auto-guiding. After a few nights of trouble shooting and some corre with SBIG it turned out to be a shot I/C. Robby bought 10 for $10 from Oz, and soldered one of them in. Works like a charm now, better than ever. Gary

[seeker372011]

glad it seems to have worked out ok but this sort of stuff is what gives us non electronics people the heebie jeebies I can tell you

[Phil]

Good to see that you got it going. Being a sparky almost half the time if you look hard enought there is a lose connecction or a wire that has fallen out.
Phil

[gbeal]

Heebie Jeebies?? Man I was sweating, especially when I saw how much he shakes, how it worked after that I don't know but it does, good old Rob.