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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: DiskChris on October 09, 2013, 05:32:10 PM

Title: Stupid Crystal Questions
Post by: DiskChris on October 09, 2013, 05:32:10 PM
Im having trouble installing the oscillator crystal...I think I have the orientation right (dot on crystal aligned with marking on board) but the crystal isnt going all the way way into the socket and I get a black screen on startup.
Title: Re: Stupid Crystal Questions
Post by: Bamiga2002 on October 09, 2013, 06:23:51 PM
Maybe you have to cut some of crystal's legs to make it align properly. That's what I did.
Title: Re: Stupid Crystal Questions
Post by: danbeaver on October 09, 2013, 06:37:35 PM
Could you show some pictures of the problem?
Title: Re: Stupid Crystal Questions
Post by: AmmoJammo on October 09, 2013, 07:36:33 PM
It doesn't need to plug the whole way in to make contact.

But, why are you replacing the crystal anyway?
Title: Re: Stupid Crystal Questions
Post by: DiskChris on October 09, 2013, 09:34:43 PM
The old one fell out of the socket and broke once when I was messing around :(
Title: Re: Stupid Crystal Questions
Post by: stefcep2 on October 10, 2013, 12:36:59 AM
If it was powered up when the crystal fell out you may have killed the CPU, resulting in the black screen.  And yes the crystal legs may not need to go all the way in depending on theor length.  Is it an Apollo board?
Title: Re: Stupid Crystal Questions
Post by: AmmoJammo on October 10, 2013, 06:28:47 AM
appears to be in the right way.

ah, how does a crystal "fall out" and more to the point, how does it then break? you could throw one at a wall and probably not break it...
Title: Re: Stupid Crystal Questions
Post by: freqmax on October 10, 2013, 06:56:00 AM
The mechanical properties of the crystal strongly influences it's signal properties.
Title: Re: Stupid Crystal Questions
Post by: DiskChris on October 10, 2013, 12:08:56 PM
Quote from: AmmoJammo;749692
appears to be in the right way.

ah, how does a crystal "fall out" and more to the point, how does it then break? you could throw one at a wall and probably not break it...

I must have caught it against the side of something....Somehow the crystal came out, and a pin broke :(.   Now I'm getting a white screen with a flickering power led....The only thing I can think of is the original crystal was 28.322 mhz and this one is 16 and maybe that's why its not working??  Its a gvp a3001 accelerator.
Title: Re: Stupid Crystal Questions
Post by: DiskChris on October 10, 2013, 12:37:19 PM
@stefcep2
It was off when it fell out (I had removed the board to get to something inside the case)
Title: Re: Stupid Crystal Questions
Post by: danbeaver on October 10, 2013, 12:50:09 PM
Just for the sake of being complete, try a new, identical crystal -- digikey has a HUGE selection.  The crystal has a corner that orients it to "pin 1" and there should be a matching mask on the board -- hence the photograph question.

P.s., are you sure it is the crystal that is "stupid?" ;-) :laughing:
Title: Re: Stupid Crystal Questions
Post by: danbeaver on October 10, 2013, 01:03:35 PM
As a side remark, I've found that a hot-glue gun is my friend.
Title: Re: Stupid Crystal Questions
Post by: AmmoJammo on October 10, 2013, 07:45:04 PM
I'm beginning to think the crystal might be backwards... but you didn't exactly give us a lot to go on...
Title: Re: Stupid Crystal Questions
Post by: DiskChris on October 11, 2013, 12:50:39 AM
The notch on the crystal was lined up with the notch on the board...
Title: Re: Stupid Crystal Questions
Post by: AmmoJammo on October 11, 2013, 06:22:44 AM
crystals don't have notches...
I thought you might have given us a decent pic by now, or at least told us what accelerator it is!
Title: Re: Stupid Crystal Questions
Post by: freqmax on October 11, 2013, 10:13:25 AM
Yes..

Picture please..
Picture plz..
Title: Re: Stupid Crystal Questions
Post by: danbeaver on October 11, 2013, 12:10:21 PM
Quote from: ammojammo;749794
crystals don't have notches...
I thought you might have given us a decent pic by now, or at least told us what accelerator it is!

The GVP A3001 has pin in the left lower position as shown (poorly) in the provided picture, so 1) orientation is correct, 2) with the legs too long (as seen in pic) it will fall out again, 3) while a 16MHz crystal "should" work, a new, known functioning replacement crystal would be best;  while I have used DigiKey for the past 25 years for buying crystals and the like, it is 6 am and I'm on my 7" tablet and don't feel like getting up and doing a search, but they have a very complete catalog of these.

Once working, seal it in place with a drop of hot-glue; my gun and supplies came from WalMart for <$10 USD