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pscm

Help with MCB on Orion Sirius EQG

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pscm

I recently acquired a used Orion Sirius EQ-G to mount my lightly used new to me ES 102 as I have decided to move from the DOB world and try my luck at some astrophotgraphy.   I bought the mount knowing it had an issue with the DEC/ALT no response message.  To date I have removed the MCB and inspected for any obvious damaged components and replaced the 2 470 uf 25v caps even though they did not indicate any damage.  I also do not see any noticeable damage to any of the micro caps, etc.   Was running some tests last night and the hand controller indicates all is well with the exception of mucking around I think I screwed up the firmware on the hand controller when I unplugged it out of frustration.  After doing this I can know not get past the last polar align information.  It as if the hand controller locks up after.  I didn't have this problem initially.  Anyways I have cables coming to firmware update and plan on doing this to the hand controller and the MCB.  The board is an HEQ5 (see attached)  I suppose if the firmware doesn't work I may be looking at a new board although I must believe someone might have some info on what I might be able to check out on the board.  I also have not been able to locate a board in the states although I did reach out to Skywatcher and they were suppose to get back to me as they thought they might be able to find one.   I have also ohmed out the cable from the controller to the MCB as well as the power board to MCB control wires. 

 

Would greatly appreciate any input on some troubleshooting info.  

Sorry about the image.  I haven't figured out how to add yet. 

Sorry I haven't figured out how to add a photo yet. 

 

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Graham

If the board is an HEQ 5 board Bernie at modern astronomy used to hold them in stock, mind it will set you back over £100.00.

Post up a photo so I can have a look at what you have there.

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Graham

Just googled  it and it certainly looks like a re-badge HEQ5.

Still like to see a high res photo of both the boards.

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pscm

Here is the top pic of the board.  I can take a pic of the bottom when I get home.  On the bottom there was one spot that has a resistor reference and the resistor is not there.  Doesn't appear that it was ever there although when looking at it at around 30x scope although I could be mistaken.  

 

https://www.dropbox.com/s/p557plbewqnqfxq/IMG_0127 (Small).jpg?dl=0

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pscm

Tonight I Went Ahead And Disassembled the power board to inspect.   The plug wires coming off the cat 5 terminal to the MCB where they come off the power board looked dodgy so I did a little surgery.  Interesting enough the red wire broke off before desoldering.  Got excited thinking I might have found the problem although got the same result.  Tomorrow I think I am going to determine if at least I have power at end of plug to ensure MCB is getting power.  Excited to see if anyone has some input.

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Tweedledee

I can't help you with the electronics, but if you want your dropbox pictures to show in the post, here's how to do it. 

 

Copy the Dropbox link >

In the post click "Insert other media" >

Click "Insert image from URL" >

Paste the link >

Change the dl=0 at the end to raw=1 >

Click "Insert into post" >

The image will then appear at the cursor position...

IMG_0130.jpg?raw=1

Edited by Tweedledee

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Graham

Well there is no doubt about that.

The main culprits are the 2 caps in the bottom left of your photo of the top.

You want to replace these with 35 volt versions.

 

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Graham

R2 should be there it is marked as 134.

Not quite sure what it does that is behind the polar scope illuminating led socket.

 

IMG_0027.JPG?raw=1

Edited by Graham

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pscm

I had actually already replaced the caps with exactly what you recommended.  I had read a thread a while back and I am pretty certain you were the one that stated this.  

On the resistor, any chance you could put an ohmmeter across this to see what reading you get.  If I can get this I may temporarily install a 1/4 watt of correct size to see if it makes it come alive.  I am also going to try and trace out and figure what role this resistor plays.

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pscm

Graham,  

Hoping you can check something for.  The little hole aft of R2 (opposite the edge of the board, can you flip it over and take a pic of the board?  I ask as on mine the circuit goes to know where.  As you are probably aware this is a double layer board.  I question if this resistor is to dim the led based on the conductor run.  I could likely tell the story if I could see the front of yours.  I am wondering if this is a difference between newer and older boards.  Mine is an HEQ5 rev B.  I thought i read somewhere that this was a complaint about the led being to bright and this got addressed.

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Graham

Yup will do that tonight. 

Have a feeling you could well be right with your theory. 

 

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Graham

Here you go Phil.

You can just see the hole under the corner of the 2 pin socket.

 

IMG_0028.JPG?raw=1

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pscm

hmm, not what I was hoping to see.  Looks just like mine.  I am going to have to get the meter going to confirm if this is simply just a light dimming function or is it more.  

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pscm

Graham,

Can you tell me the model and rev number on your board?

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pscm

Well, tonight has been interesting and a night of discovery albeit not what I wanted to find.  To start with I got bored waiting for my update cables so I dug through some stuff and made my own 🙂 .   This addressed the issues I created in the handset.  I quickly discovered that I was not able to update the motor controller firmware which really had me thinking it was dead.  I decided to take a look inside the hand controller and got a bit of a surprise.  I found some badness.  One blown cap and a ferrite bead.  I am quite certain I can get the number from the cap just below which is likely the same although I cannot identify what the ferrite bead next to it or for that matter any of the others sitting around it which I can only guess is the same.  Would love to try and fix this although I am stumped on how to identify.  

IMG_0143.jpg?raw=1

IMG_0145.jpg?raw=1

 

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pscm

After another look I believe the ferrite bead is ok and it was jus the remnants of the capacitor blowing.  The capacitor has three sets of numbers on it in this order:  106, 16k 537.   

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Graham

Thats a bit of a mess. 

Might have been caused when you unplugged the handset. 

Unfortunately I do not have any handsets so cannot help with identification of these bits. 

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pscm

Appreciate all you have done to date.  Based on where the circuit appears to track I suspect this is what supply the board with the missing information.  I will report back which ever route I go.

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pscm

I have been able to figure out the capacitor.  From some reading the small black three pin item to the right of that would be suspect.  It is identified with the numbers 564L NO50A.  I cannot identify this little guy.  I may order the capacitor for what it costs and roll the dice.  Any help identifying the other guy would be appreciated. 

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pscm

Have figured out the regulator with some help over on CN.  Will report back when the parts come in.

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Graham

If you mean U 10 it is an Integrated Circuit.

Probably for data transfer. 

Edited by Graham

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