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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: arttu80 on January 16, 2011, 10:26:42 PM

Title: I made some smoke on A500...
Post by: arttu80 on January 16, 2011, 10:26:42 PM
So I killed her! Now, that wasn't very funny at all. First I managed to rescue this one A500, when I noticed it had cracked soldering on motherboard where sqaure power socket attached, the disk drive didn't work because of that. After repair it worked fine.

But now I busted whole thing, when tried my "newly power hacked" (used ATX to power both) A590 on this poor thing, before I mated it to A1k. By mistake I din't doublecheck everything and it shorted somewhere where I put extra wires underneath! :( Well lucky me, A590 was fine, but not so A500. Nasty smelling smoke protruded under the case and it didn't power up anymore.

So after opening cover I noticed smoke traces under RF-shield where LF1 "line filter" sits, right behind that sqare power socket! I think fault is there, no power goes to machine. So what do you think, can I get that component somewhere to try repair or should I use this machine for parts?

 Here is pix of this component  (not my burned one)--->
http://www.aijaa.com/v.php?i=7327514.jpg

BTW... Now A590 works fine with A1000, only using Amiga power supply, no externals.

http://www.aijaa.com/v.php?i=7323561.jpg
Title: Re: I made some smoke on A500...
Post by: Iggy on January 16, 2011, 10:55:31 PM
Quote from: arttu80;607130
So I killed her! Now, that wasn't very funny at all. First I managed to rescue this one A500, when I noticed it had cracked soldering on motherboard where sqaure power socket attached, the disk drive didn't work because of that. After repair it worked fine.

But now I busted whole thing, when tried my "newly power hacked" (used ATX to power both) A590 on this poor thing, before I mated it to A1k. By mistake I din't doublecheck everything and it shorted somewhere where I put extra wires underneath! :( Well lucky me, A590 was fine, but not so A500. Nasty smelling smoke protruded under the case and it didn't power up anymore.

So after opening cover I noticed smoke traces under RF-shield where LF1 "line filter" sits, right behind that sqare power socket! I think fault is there, no power goes to machine. So what do you think, can I get that component somewhere to try repair or should I use this machine for parts?

 Here is pix of this component  (not my burned one)--->
http://www.aijaa.com/v.php?i=7327514.jpg

BTW... Now A590 works fine with A1000, only using Amiga power supply, no externals.

http://www.aijaa.com/v.php?i=7323561.jpg


Ouch! I'm glad that didn't happen to me when I wired an adapter for an ATX power supply I was thinking of using in my Powermac(it just didn't work). But those are the risks you take when you decide to undertake such a project.
You have my sympathy.
Title: Re: I made some smoke on A500...
Post by: ElPolloDiabl on January 17, 2011, 01:27:51 AM
It's a cheap enough part to replace, but I have a feeling other things may have burnt too.
Title: Re: I made some smoke on A500...
Post by: Ral-Clan on January 17, 2011, 02:17:41 AM
Don't feel too bad.

A few years ago I killed an A500 by connecting a Commodore 128 power supply to it....they look the same externally and I had been told they were compatible....but I didn't check the voltages.....ouch!  Smoke and a piece of one chip actually flew off!
Title: Re: I made some smoke on A500...
Post by: marcfrick2112 on January 17, 2011, 09:35:26 AM
arrto80; Ouch! At least the 590 is OK.. 500's are cheaper to get, in comparison...

I miss my tricked out 500 system.. :( (Full ECS, Supra SCSI w. 640MB HD and 100MB zip, '030/32MB ....)

:(
Title: Re: I made some smoke on A500...
Post by: arttu80 on January 17, 2011, 10:32:56 AM
Quote from: ElPolloDiabl;607201
It's a cheap enough part to replace, but I have a feeling other things may have burnt too.


But can I buy this part somewhere? Is it standard electronic component or A500 specific? Ofcourse these machines are unexpensive here, but still I must try a rescue once more.
Title: Re: I made some smoke on A500...
Post by: ElPolloDiabl on January 17, 2011, 10:42:29 AM
Quote from: arttu80;607259
But can I buy this part somewhere? Is it standard electronic component or A500 specific? Ofcourse these machines are unexpensive here, but still I must try a rescue once more.

It's a standard part. Someone else will know exactly what it is.

Here is what I think it is:
http://www.jaycar.com.au/productResults.asp?whichpage=1&pagesize=10&keywords=choke&form=KEYWORD (http://www.jaycar.com.au/productResults.asp?whichpage=1&pagesize=10&keywords=choke&form=KEYWORD)

Filter or a choke.
Title: Re: I made some smoke on A500...
Post by: gertsy on January 17, 2011, 11:06:44 AM
Quote from: ElPolloDiabl;607261
It's a standard part. Someone else will know exactly what it is.

Here is what I think it is:
http://www.jaycar.com.au/productResults.asp?whichpage=1&pagesize=10&keywords=choke&form=KEYWORD (http://www.jaycar.com.au/productResults.asp?whichpage=1&pagesize=10&keywords=choke&form=KEYWORD)

Filter or a choke.


Yep it's a ferrite choke, which is usually paired with a voltage regulator.  This was a common part to blow on a ZX Spectrum if the polarity of the pwr supply was incorrect.... ( o:  That and the voltage regulator. It is more than likely that this wasn't the only thing to go on the board. I wish it wasnt the case and I hope I'm wrong, but I don't think you will have much chance of finding all that smoke and getting it back in place.
Look at it as a learning experience and a worse case way of freeing up lots of spare custom chips and a processor.

Good luck.
Title: Re: I made some smoke on A500...
Post by: arttu80 on January 17, 2011, 11:25:24 AM
Oh, I guess you are right about that. The case was pretty yellowed anyway and it was Rev.5 mobo, so maybe I make this my spare parts machine, at least it has working keyboard and a floppy drive to make other Amigas live :)
Title: Re: I made some smoke on A500...
Post by: gertsy on January 17, 2011, 11:30:21 AM
Quote from: arttu80;607263
Oh, I guess you are right about that. The case was pretty yellowed anyway and it was Rev.5 mobo, so maybe I make this my spare parts machine, at least it has working keyboard and a floppy drive to make other Amigas live :)


Dare I say you can fix a yellowing case...http://retr0bright.wikispaces.com/
Title: Re: I made some smoke on A500...
Post by: Karlos on January 17, 2011, 11:49:52 AM
I once allowed the MBS (magic blue smoke) escape from an A1200 once. It never worked again, either.

Once you let the MBS out, that's it.
Title: Re: I made some smoke on A500...
Post by: spirantho on January 17, 2011, 12:27:42 PM
Not true, actually. Some really special systems work afterwards. But not many.

In some ways, the Magic Smoke is good because it lets you see what's wrong. Better that than a dried up electrolytic. My A4000 has a cremated SMT resistor (the audio circuitry I think), a couple of bodged normal resistors, and black scorch marks - it works just fine. (It was a dodgy backplane that caused it, for those who are interested).

Don't give up on things which have let out the MBS, you can usually put it back in. Unless you do something really stupid like use the video cable as a lightning conductor. Then you're on your own.
Title: Re: I made some smoke on A500...
Post by: Karlos on January 17, 2011, 12:39:40 PM
Yeah, what Ian said there is fair. It sort of depends how much MBS got out, and where it leaked from as to whether or not you should attempt a repair.

In my A1200's case, a freak short-circuit induced potential difference of 24 V (essentially between the +12V and -12V rails)  caused pretty much all the MBS to escape from yon delicate 5VDC parts.
Title: Re: I made some smoke on A500...
Post by: arttu80 on January 17, 2011, 01:05:36 PM
Quote from: gertsy;607264
Dare I say you can fix a yellowing case...http://retr0bright.wikispaces.com/


I hate chemistry! :) With my luck I end up being blinded or something... But it would be really cool to test and see the results personally. Have you tried?

On MBS topic; yes lots of it escaped this computer that day! Without in depth knowledge of electronics I think I'll take it as a lesson to myself.
Title: Re: I made some smoke on A500...
Post by: gertsy on January 17, 2011, 01:09:42 PM
Quote from: arttu80;607272
I hate chemistry! :) With my luck I end up being blinded or something... But it would be really cool to test and see the results personally. Have you tried?

On MBS topic; yes lots of it escaped this computer that day! Without in depth knowledge of electronics I think I'll take it as a lesson to myself.


On retrobright, no I haven't but if you search this forum you will find a few posts that settle on how to get consistent results.  Also straight peroxide can be difficult to get in some countries, like Australia.  )o: