Problems since my AVX mount got damp

[james_screech]

Until recently I've been able to guide my AVX mount without a problem (I could get 10min exposures with an 8" SCT @ f10 without any problems).

However at the end of last year the mount (stored in a shed) got rather wet due to damp weather lasting a few weeks and it has not been the same since.

The RTC no-longer works (not a major problem, just irritating having to put the time / date (in an odd format) in each time.

Every other time I start the mount and enter the date/time I then get an no-response error message, wiggling the cables and re-starting solves this one.

But the biggest problem is that it now will not guide!

When I try to calibrate PHD2 E/W is fine but N/S causes the guide star to jump about randomly. I've tried both pulse guiding and ST-4 but both are the same and so it manual guiding in PHD.

Apart from a new hand controller and/or new motor control board is there anything else I could try?

James

[leelee970]

The only suggestion would be to take a look at all the sockets and plugs to see if they are corroded. Then use a cotton wool bud and apply a little bit of WD40 on the pins etc.

Lee

[Grotemobile]

http://www.amazon.co.uk/s/?ie=UTF8&keywords=contact+cleaner&tag=mh0a9-21&index=aps&hvadid=3170413124&ref=pd_sl_ykeu0kqgg_e

Using something like this, might help.

I have used, contact cleaner, on loads of things.

Would not be with out it.Take your pick.

[Chris]

As above, it sounds like its been exposed to high humidity for a while so could well be a corroded connection, the above advice sounds good to me, certainly worth a go.

[james_screech]

I can see how cleaning the contacts might solve the no response problem, however my main issue is why guiding no-longer works. And I don't think cleaning contacts can solve that as the problem exists on pulse guiding as well as when using the guide port.

James

[Baffa]

There could be moisture trapped somewhere and it could take a long time before it's evaporated. Bring the mount indoors and let it dry out for a week, or more.

[james_screech]

Well I've now replaced the battery, checked and cleaned the connections. I had previously dried everything out. 

The RTC now works  .

There are no more no-response errors  .

However guiding still does not work  .

James

[StuartJPP]

However guiding still does not work  .

James

This is DEC guiding I presume (due to N/S being the problem).

Is there a setting for guide rate that has got corrupted? Could be set too large. e.g. RA guide rate set to 0.5x but DEC set to 1.0x or some other invalid value. Can check this in both PHD2 and on the hand controller.

Did you have a backlash compensation value set previously in the handset that got lost due to the battery failing? I am not at all familiar with this mount mind you.

Does the mount slew in DEC properly, i.e. does it sound right and not labouring, something could be gummed up and sticking?

You could try slewing in DEC at a slow speed with the handset and see if a star moves smoothly or jumps around.

Does it jump, then settle when manually guiding in one direction (e.g. North)? Doesn't sound like it from your initial description, you say it jumps around all the time?

[MiguelMJr]

this is what I would do.....

Clean all the electronics with contact cleaner and a gentle brush, make sure to not miss any places. Spray rinse with good quality isopropyl alcohol and put in a warm oven for a hour or so. The boards should end up looking clean and shiny and be nice and dry. Visual inspect the boards under bright light for signs of any possible shorts.

Miguel

[james_screech]

This is DEC guiding I presume (due to N/S being the problem).

Is there a setting for guide rate that has got corrupted? Could be set too large. e.g. RA guide rate set to 0.5x but DEC set to 1.0x or some other invalid value. Can check this in both PHD2 and on the hand controller.

Did you have a backlash compensation value set previously in the handset that got lost due to the battery failing? I am not at all familiar with this mount mind you.

Does the mount slew in DEC properly, i.e. does it sound right and not labouring, something could be gummed up and sticking?

You could try slewing in DEC at a slow speed with the handset and see if a star moves smoothly or jumps around.

Does it jump, then settle when manually guiding in one direction (e.g. North)? Doesn't sound like it from your initial description, you say it jumps around all the time?

Guide rates are both set to .5, manual guiding in PHD has the same problem (random star movement) backlash has been reset back to previous values. Dec movements from hand controler are fine.

James