A1200 does not boot

Jerry · 13 August 2015, 17:35

I'm having a go at an Amiga 1200 which has been lying around broken for a while. When booting the power led will light dimly and the caps lock flashes, however the screen most of the time will give me a black/dark grey color.

Sometimes (more often on warm boots than cold boots) I get a flashing image which seems to have the wrong frequency and the monitor goes out of sync after 2 or so seconds.

Putting in a turboboard does not make any difference so I guess it's not a faulty cpu (though the grey/black color advocates a problem with it).

Anyone have any pointers what to check?

Amiga1992 · 13 August 2015, 17:40

Suspect #1: Power supply. Check with another power supply
Suspect #2: capacitors. Get it recapped.

Do NOT put a turbocard or any other peripherals on a possibly broken computer, you could toast them.

Jerry · 13 August 2015, 17:46

Power supply works fine with a different A1200 so I don't think that's the problem.

Arnie · 13 August 2015, 17:56

Unplug everything from the board, Hard Drives, Floppy drives, keyboard all cables and then try booting.

Check the caps for bulging or leaking, check board for damaged traces or corrosion.

Try the modulator, composite and RGB to see if you get any picture.

Send to Amigakit for recap/repair or many users on this forum can probably help.

Jerry · 13 August 2015, 18:23

From an photo of the mainboard (its a Rev 2B one) I found out, that the kickstart rom chips where swapped. Unfortunately correcting that did not fix all the problems. However I know get a steady black screen when booting. No more strange color flickering...

I may have to go down the recap route but all caps look fine.

Retrofan · 13 August 2015, 18:41

I would send the board to AmigaKit, it better has a recap and the timing fixes are appropiate too while you are at it if it needs them and you buy an ACA later.

Amiga1992 · 13 August 2015, 19:44

Quote:

Originally Posted by Jerry

I may have to go down the recap route but all caps look fine.

My experience dictates that caps go bad WITHOUT showing any physical signs of them being bad. I would think a recap is in place in your case.

ElectroBlaster · 13 August 2015, 23:52

I have an a1200 that has never worked in stock form ever since I was given it. Sometime around 1995? It just does not work unless an accelerator or memory expansion is fitted. I never bothered to get it sorted, maybe I should now.

Smakar · 14 August 2015, 01:10

My Amiga 1200 just stopped working - solid green power light but nothing else. I was going to try to re-cap it myself but I am NOT an electrician. I found a re-cap service on eBay: http://www.ebay.com/itm/181827886938...%3AMEBIDX%3AIT
I just shipped my motherboard to him this morning and keeping my fingers crossed.

Retrofan · 14 August 2015, 12:21

Quote:

Originally Posted by Smakar

My Amiga 1200 just stopped working - solid green power light but nothing else. I was going to try to re-cap it myself but I am NOT an electrician. I found a re-cap service on eBay: http://www.ebay.com/itm/181827886938...%3AMEBIDX%3AIT
I just shipped my motherboard to him this morning and keeping my fingers crossed.

Ejem... US $69.00 . Do you know that AmigaKit makes that for 29,95 pounds? And you don't need fingers crossed with them.

Amiga1992 · 14 August 2015, 14:59

Quote:

Originally Posted by Retrofan

Ejem... US $69.00 . Do you know that AmigaKit makes that for 29,95 pounds?

Not everyone feels sending a motherboard across the Atlantic is safe or cheap.

Retrofan · 14 August 2015, 15:06

Yes you are true. I wonder if there aren't enough amiga users in the States to open an Amiga shop there.

fryguy · 14 August 2015, 15:11

Quote:

Originally Posted by Arnie

Unplug everything from the board, Hard Drives, Floppy drives, keyboard all cables and then try booting.

Check the caps for bulging or leaking, check board for damaged traces or corrosion.

Try the modulator, composite and RGB to see if you get any picture.

Send to Amigakit for recap/repair or many users on this forum can probably help.

Don't send it to Amigakit. You'll probably have to wait a few years to get it back and it might work worse.

15 August 2015, 02:29

oh really i was thinking of sending them my amiga to them amigakit i mean

Retrofan · 15 August 2015, 02:43

Quote:

Originally Posted by dimitrious

oh really i was thinking of sending them my amiga to them amigakit i mean

It's a hard job with some of the caps if you don't have skills/good soldering iron (traces can get up). You don't have much room either for the ones behind the keyboard connector.

Just ask them before to have an expected time.

Amicol · 15 August 2015, 02:51

I replaced the caps on my 2 A1200's with ceramic ones a couple of years ago.
Still working perfectly and no chance of leakage....

Retrofan · 15 August 2015, 03:24

Depending on his spare time/ability, if he thinks in making it I would look and spend the money in some trusted soldering iron, and later I would watch some videos. Cosmos can sell you a kit of caps http://leblogdecosmos.blogspot.com.es/

15 August 2015, 03:24	#17
Retrofan Ruler of the Universe Join Date: Mar 2010 Location: Lanzarote/Spain Posts: 6,190	Depending on his spare time/ability, if he thinks in making it I would look and spend the money in some trusted soldering iron, and later I would watch some videos. Cosmos can sell you a kit of caps http://leblogdecosmos.blogspot.com.es/ Last edited by Retrofan; 15 August 2015 at 03:33.

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13 August 2015, 17:35	#1
Jerry Registered User Join Date: Mar 2005 Location: Germany Age: 44 Posts: 210	A1200 does not boot I'm having a go at an Amiga 1200 which has been lying around broken for a while. When booting the power led will light dimly and the caps lock flashes, however the screen most of the time will give me a black/dark grey color. Sometimes (more often on warm boots than cold boots) I get a flashing image which seems to have the wrong frequency and the monitor goes out of sync after 2 or so seconds. Putting in a turboboard does not make any difference so I guess it's not a faulty cpu (though the grey/black color advocates a problem with it). Anyone have any pointers what to check?

13 August 2015, 17:40	#2
Amiga1992 Registered User Join Date: May 2001 Location: ? Posts: 19,645	Suspect #1: Power supply. Check with another power supply Suspect #2: capacitors. Get it recapped. Do NOT put a turbocard or any other peripherals on a possibly broken computer, you could toast them.

13 August 2015, 17:46	#3
Jerry Registered User Join Date: Mar 2005 Location: Germany Age: 44 Posts: 210	Power supply works fine with a different A1200 so I don't think that's the problem.

13 August 2015, 17:56	#4
Arnie R.I.P Smudge 18-08-16 Join Date: Aug 2005 Location: Leicester/UK Age: 66 Posts: 3,968	Unplug everything from the board, Hard Drives, Floppy drives, keyboard all cables and then try booting. Check the caps for bulging or leaking, check board for damaged traces or corrosion. Try the modulator, composite and RGB to see if you get any picture. Send to Amigakit for recap/repair or many users on this forum can probably help.

13 August 2015, 18:23	#5
Jerry Registered User Join Date: Mar 2005 Location: Germany Age: 44 Posts: 210	From an photo of the mainboard (its a Rev 2B one) I found out, that the kickstart rom chips where swapped. Unfortunately correcting that did not fix all the problems. However I know get a steady black screen when booting. No more strange color flickering... I may have to go down the recap route but all caps look fine.

13 August 2015, 18:41	#6
Retrofan Ruler of the Universe Join Date: Mar 2010 Location: Lanzarote/Spain Posts: 6,190	I would send the board to AmigaKit, it better has a recap and the timing fixes are appropiate too while you are at it if it needs them and you buy an ACA later.

13 August 2015, 23:52	#8
ElectroBlaster Junior Member Join Date: Mar 2002 Location: Exeter, Devon, UK Age: 49 Posts: 1,706	I have an a1200 that has never worked in stock form ever since I was given it. Sometime around 1995? It just does not work unless an accelerator or memory expansion is fitted. I never bothered to get it sorted, maybe I should now.

14 August 2015, 01:10	#9
Smakar Amiga Fan in Phoenix Join Date: Aug 2012 Location: Phoenix, AZ USA Age: 66 Posts: 60	My Amiga 1200 just stopped working - solid green power light but nothing else. I was going to try to re-cap it myself but I am NOT an electrician. I found a re-cap service on eBay: http://www.ebay.com/itm/181827886938...%3AMEBIDX%3AIT I just shipped my motherboard to him this morning and keeping my fingers crossed.

14 August 2015, 15:06	#12
Retrofan Ruler of the Universe Join Date: Mar 2010 Location: Lanzarote/Spain Posts: 6,190	Yes you are true. I wonder if there aren't enough amiga users in the States to open an Amiga shop there.

15 August 2015, 02:29	#14
dimitrious Posts: n/a	oh really i was thinking of sending them my amiga to them amigakit i mean

15 August 2015, 02:51	#16
Amicol Registered User Join Date: Dec 2013 Location: Hartlepool / England Posts: 389	I replaced the caps on my 2 A1200's with ceramic ones a couple of years ago. Still working perfectly and no chance of leakage....

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