Help! - A1200 with Memory Expansion Problems

xaind · 20 December 2007, 02:41

Hi All,

My brother and I are having problems with an Amiga 1200 we recently picked up from ebay. It appears to have originally been a regular A1200 with no hard-drive that someone has added a 4GB hard-drive to. It has 3.0 ROMS. The computer works fine normally, but has problems when we try to add a ram expansion to it.

We have tried 3 different A1200 RAM expansions. Two of them are Microbotics MBX 1200z models, one with 8MB RAM and one with 4MB. Both have FPU chips in them. When we power-on the A1200 with either of these installed the screen comes up black and nothing happens. We have tested both of them in another A1200 and they work fine.

The third RAM expansion we have tried is an Amitek Hawk 4MB with no FPU. When we power-on with this one the power-led on the A1200 flashes and sometimes a red diagnostic screen comes up reporting a problem with the board, we also sometimes see the guru, but if we reset the A1200 a couple of times it will eventually boot up normally and the RAM is detected by workbench and appears to work properly for simple tests like copying things to the RAM disk and running Sysinfo's speed test. If we reset or power-off the machine though we have to go through the guru's and multiple-resets again to get it to work again.

We have tried using an A500 power-supply in case it was a power issue, but it seemed to make no difference.

Can anyone out there provide any suggestions as to what the problem might be or how we might go about fixing it? Would 3.1 ROMs help? Is it something to do with the 4GB hard-drive that has been added? Any help or advice would be greatly appreciated!

Thanks.

Zetr0 · 20 December 2007, 03:25

@xaind

Hello there,

Welcome to the EAB, theres plenty of mischief to get up to round here, but let us first see if we can help with this problem.

To begin with, well done on what is a lot of effort both yourself and your brother have done, most would of given up by now or run out of hair to pull.
However from your efforts it can only conclude one of two things.

1. Your A1200 motherboard is of an old and incompatible revision, there are workaround's if you are a little handy with a soldering iron. but before we take that step there is one last thing to try.

we can take out the hard drive and implant it into the working A1200 with the memory card in.

If you get errors at this point, I would hazard a guess you are suffering from a large power drain. you may need to get another PSU, or if you are willing to modify an existing PC PSU

you will find schematics for them on these fair boards.

OK... so i suggest you relax.. chill for a smidge grab a drink and kick back, you guys have earned it from all that messing around. let some more posts fill in here to give you some more ideas. while your doing so... make yourself at home and enjoy the honey coated retro-dom as this fine board provides

fc.studio · 20 December 2007, 08:39

My suggestions:
- If you have one, verify internal A1200 metal shield doesn't touch with your ram board. It's easy it could happen.
- If your hard drive is 3,5" try to disconnect it. If power hard drive is the problem install a 2,5" one or a Compact Flash (better).
- Clean deep Amiga trapdoor connector.
- Remove, clean and re-install RAM SIMM (FIRMLY, I had problems in the past believing, and I was wrong, my RAM SIMM was correctly installed). Try to verify memory with programs like memcheck or similar...

About power with A500 PSU only, I run 2,5" Hard Drive (3,4 GB) + Blizzard 1230/IV + FPU + 16 MB with no problems. In the past this configuration worked with a CD drive attached.

Toni Wilen · 20 December 2007, 09:13

Quote:

Originally Posted by Zetr0

1. Your A1200 motherboard is of an old and incompatible revision, there are workaround's if you are a little handy with a soldering iron. but before we take that step there is one last thing to try.

MB/chip revision bugs only affect (some) accelerators. Memory expansions don't care

Eliotg · 20 December 2007, 18:18

clean the connectors on the A1200 motherboard with alcohol or something like that.....up and down

xaind · 21 December 2007, 08:16

Thanks all for the posts.

I will try your suggestions and let you know how it goes!

Charlie · 21 December 2007, 11:36

@Eliotg:
Welcome the the EAB.

I hope you enjoy your stay - do stick around.

Fingerlickin_B · 21 December 2007, 12:49

Dude, I see from your profile that you are in AU, but it doesn't say where.

I've been asking questions and learning stuff on here for a while, plus I have an 1200 with loads of extra bits we could test.

If you are in or near the ACT, let me know and I'd be happy to help in any way I can

PZ.

20 December 2007, 02:41	#1
xaind Registered User Join Date: Apr 2006 Location: Sydney / Australia Posts: 113	Help! - A1200 with Memory Expansion Problems Hi All, My brother and I are having problems with an Amiga 1200 we recently picked up from ebay. It appears to have originally been a regular A1200 with no hard-drive that someone has added a 4GB hard-drive to. It has 3.0 ROMS. The computer works fine normally, but has problems when we try to add a ram expansion to it. We have tried 3 different A1200 RAM expansions. Two of them are Microbotics MBX 1200z models, one with 8MB RAM and one with 4MB. Both have FPU chips in them. When we power-on the A1200 with either of these installed the screen comes up black and nothing happens. We have tested both of them in another A1200 and they work fine. The third RAM expansion we have tried is an Amitek Hawk 4MB with no FPU. When we power-on with this one the power-led on the A1200 flashes and sometimes a red diagnostic screen comes up reporting a problem with the board, we also sometimes see the guru, but if we reset the A1200 a couple of times it will eventually boot up normally and the RAM is detected by workbench and appears to work properly for simple tests like copying things to the RAM disk and running Sysinfo's speed test. If we reset or power-off the machine though we have to go through the guru's and multiple-resets again to get it to work again. We have tried using an A500 power-supply in case it was a power issue, but it seemed to make no difference. Can anyone out there provide any suggestions as to what the problem might be or how we might go about fixing it? Would 3.1 ROMs help? Is it something to do with the 4GB hard-drive that has been added? Any help or advice would be greatly appreciated! Thanks.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Wanted: A1200 memory expansion	arti	MarketPlace	0	28 August 2013 12:51
A1200 memory expansion wanted	commodoresales	MarketPlace	0	17 March 2012 00:01
Looking for memory expansion for A1200	paulo_becas	MarketPlace	1	12 April 2010 14:10
Wanted: A1200 memory expansion	lpopman	MarketPlace	1	12 January 2010 00:12
A1200 memory expansion	Another World	New to Emulation or Amiga scene	16	03 October 2008 20:21

20 December 2007, 03:25	#2
Zetr0 Ya' like it Retr0? Join Date: Jul 2005 Location: United Kingdom Age: 49 Posts: 9,768	@xaind Hello there, Welcome to the EAB, theres plenty of mischief to get up to round here, but let us first see if we can help with this problem. To begin with, well done on what is a lot of effort both yourself and your brother have done, most would of given up by now or run out of hair to pull. However from your efforts it can only conclude one of two things. 1. Your A1200 motherboard is of an old and incompatible revision, there are workaround's if you are a little handy with a soldering iron. but before we take that step there is one last thing to try. we can take out the hard drive and implant it into the working A1200 with the memory card in. If you get errors at this point, I would hazard a guess you are suffering from a large power drain. you may need to get another PSU, or if you are willing to modify an existing PC PSU you will find schematics for them on these fair boards. OK... so i suggest you relax.. chill for a smidge grab a drink and kick back, you guys have earned it from all that messing around. let some more posts fill in here to give you some more ideas. while your doing so... make yourself at home and enjoy the honey coated retro-dom as this fine board provides

20 December 2007, 08:39	#3
fc.studio Cat lover Join Date: May 2004 Location: Italy Age: 54 Posts: 804	My suggestions: - If you have one, verify internal A1200 metal shield doesn't touch with your ram board. It's easy it could happen. - If your hard drive is 3,5" try to disconnect it. If power hard drive is the problem install a 2,5" one or a Compact Flash (better). - Clean deep Amiga trapdoor connector. - Remove, clean and re-install RAM SIMM (FIRMLY, I had problems in the past believing, and I was wrong, my RAM SIMM was correctly installed). Try to verify memory with programs like memcheck or similar... About power with A500 PSU only, I run 2,5" Hard Drive (3,4 GB) + Blizzard 1230/IV + FPU + 16 MB with no problems. In the past this configuration worked with a CD drive attached.

20 December 2007, 18:18	#5
Eliotg Banned Join Date: Dec 2007 Location: Motherearth Posts: 41	clean the connectors on the A1200 motherboard with alcohol or something like that.....up and down

21 December 2007, 08:16	#6
xaind Registered User Join Date: Apr 2006 Location: Sydney / Australia Posts: 113	Thanks all for the posts. I will try your suggestions and let you know how it goes!

21 December 2007, 11:36	#7
Charlie . . Mouse . . Join Date: Jun 2005 Location: Nowhere Age: 55 Posts: 1,792	@Eliotg: Welcome the the EAB. I hope you enjoy your stay - do stick around.

21 December 2007, 12:49	#8
Fingerlickin_B Amiga Nut Join Date: Oct 2006 Location: Belco, Australia Posts: 2,242	Dude, I see from your profile that you are in AU, but it doesn't say where. I've been asking questions and learning stuff on here for a while, plus I have an 1200 with loads of extra bits we could test. If you are in or near the ACT, let me know and I'd be happy to help in any way I can PZ.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)