Temperamental A1200 Tower

mihcael · 13 January 2011, 09:50

Having some issues with me A1200 Tower. Its been a bit sporadic since ive had it, but now its getting to the point where it wont boot at all.

When it boots. the only obvious problem is
- Mouse cursor is often glitchy/corrupted/jumpy, gets worse over time. (this also effects sprites in pinball illusions)

Other times, randomly it just wont boot
. Mostly black screen the flashes a little every 4-5 seconds
. Sometimes it gives a Red screen
. Sometimes it gives a Yellow Screen

Anything i should be looking at to solve this? What info can i provide to help diagnose this??

Thanks, mike

Bamiga2002 · 13 January 2011, 10:01

Check ROM seatings, try a different ROM-set.

mihcael · 13 January 2011, 10:16

Quote:

Originally Posted by Bamiga2002

Check ROM seatings, try a different ROM-set.

I will try re-seating. Is it safe to handle the roms? Ive never done it before.

I cant try others as i dont have any

Amigafanboi · 13 January 2011, 12:14

Use a small screwdriver or idealy a plastic alternative to prise them bit by bit at each end of the roms til they come free and then reseat them. Be careful to have the pins lined up properly as they bend easily.
Also if you have an accelerator card remove and clean the contacts on the card and the motherboard.

musashi5150 · 13 January 2011, 12:16

Quote:

Originally Posted by mihcael

Is it safe to handle the roms? Ive never done it before

Pretty much as long as you don't rub your socks on the carpet first

If you are worried do it near a radiator or metal pipe and touch that first to ground you a bit. Then just prise them out carefully with a flat screwdriver and reseat.

mihcael · 13 January 2011, 12:38

Thanks for the tips, i will be attempting this tomorrow.

One thing i noticed, it looks like there are contacts that are not used by the ROM chips (on the end closest PCMCIA). Normal?

fitzsteve · 13 January 2011, 12:47

Quote:

Originally Posted by mihcael

Thanks for the tips, i will be attempting this tomorrow.

One thing i noticed, it looks like there are contacts that are not used by the ROM chips (on the end closest PCMCIA). Normal?

Yes that is correct, the roms go to the right and that one is left empty

mihcael · 14 January 2011, 05:17

Quote:

Originally Posted by Bamiga2002

Check ROM seatings...

Tried this, took them out, looked at them

seemed fine, put them back in. It made no difference.

-Without RAM or Accelerator card, it rarely boots.

When i put the RAM board back in booted up but still weird cursor.
Then warm boot failed.
Next cold boot had Red then Yellow screen.

Could this be a power supply issue? I have ATX power supply and these PC PSU things are extremely unreliable.

cosmicfrog · 14 January 2011, 10:26

could be a power problem or a caps problem
but first I`d rule out the onboard memory if u can by running a memchecker

Bamiga2002 · 14 January 2011, 10:30

Do you have a normal A500/A1200 PSU you could try, just remember to keep extra peripherals to minimum (especially with an A1200 PSU).

mihcael · 14 January 2011, 12:18

Quote:

Originally Posted by cosmicfrog

could be a power problem or a caps problem
but first I`d rule out the onboard memory if u can by running a memchecker

Dont know anything about caps, hopefully it doesn't come to that.

but what memchecker should i try?

Quote:

Originally Posted by Bamiga2002

Do you have a normal A500/A1200 PSU you could try, just remember to keep extra peripherals to minimum (especially with an A1200 PSU).

I have any A500 PSU i can try.
I have already disconnected the 3.5" HD, CDROM and ZIP Drive

JuvUK · 14 January 2011, 12:58

you're using a standard miggy PSU?

cosmicfrog · 14 January 2011, 13:04

Quote:

what memchecker should i try?

one that works heheheheheheh

a quick search on aminet will help

http://aminet.net/search?query=memcheck

mihcael · 14 January 2011, 19:13

Quote:

Originally Posted by JuvUK

you're using a standard miggy PSU?

No. Using ATX power from the tower

rkauer · 15 January 2011, 04:14

Memory testing will not work correctly if faulty power is occurring. Test the +5V rail (better with an oscilloscope) prior to blame memory chips!

mihcael · 15 January 2011, 05:16

Quote:

Originally Posted by rkauer

Memory testing will not work correctly if faulty power is occurring. Test the +5V rail (better with an oscilloscope) prior to blame memory chips!

I will test power first then, can you explain how to test the +5V rail please. (i have only a multimetre)

rkauer · 16 January 2011, 06:42

Analogic or digital? Put the analogic/digital on AC measurement (sic!) on the best possible measurement (up to ~2V on digital) and read the ripple: it must be lower than 0.05V.

With an oscilloscope things are easier to read, but even an ordinary meter can do wonders when you know how to use it.

13 January 2011, 09:50	#1
mihcael Zone Friend Join Date: Jan 2006 Location: Aussie Posts: 1,144	Temperamental A1200 Tower Having some issues with me A1200 Tower. Its been a bit sporadic since ive had it, but now its getting to the point where it wont boot at all. When it boots. the only obvious problem is - Mouse cursor is often glitchy/corrupted/jumpy, gets worse over time. (this also effects sprites in pinball illusions) Other times, randomly it just wont boot . Mostly black screen the flashes a little every 4-5 seconds . Sometimes it gives a Red screen . Sometimes it gives a Yellow Screen Anything i should be looking at to solve this? What info can i provide to help diagnose this?? Thanks, mike

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13 January 2011, 10:01	#2
Bamiga2002 BlizzardPPC'less Join Date: May 2004 Location: Finland Age: 46 Posts: 3,210	Check ROM seatings, try a different ROM-set.

13 January 2011, 12:14	#4
Amigafanboi Registered User Join Date: Oct 2010 Location: Fareham Hampshire Age: 54 Posts: 142	Use a small screwdriver or idealy a plastic alternative to prise them bit by bit at each end of the roms til they come free and then reseat them. Be careful to have the pins lined up properly as they bend easily. Also if you have an accelerator card remove and clean the contacts on the card and the motherboard.

13 January 2011, 12:38	#6
mihcael Zone Friend Join Date: Jan 2006 Location: Aussie Posts: 1,144	Thanks for the tips, i will be attempting this tomorrow. One thing i noticed, it looks like there are contacts that are not used by the ROM chips (on the end closest PCMCIA). Normal?

14 January 2011, 10:26	#9
cosmicfrog The 1 who ribbits Join Date: Apr 2006 Location: leek, Staffs, UK Age: 56 Posts: 3,557	could be a power problem or a caps problem but first I`d rule out the onboard memory if u can by running a memchecker

14 January 2011, 10:30	#10
Bamiga2002 BlizzardPPC'less Join Date: May 2004 Location: Finland Age: 46 Posts: 3,210	Do you have a normal A500/A1200 PSU you could try, just remember to keep extra peripherals to minimum (especially with an A1200 PSU).

14 January 2011, 12:58	#12
JuvUK Registered User Join Date: Oct 2008 Location: Cheltenham/UK Age: 52 Posts: 312	you're using a standard miggy PSU?

15 January 2011, 04:14	#15
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	Memory testing will not work correctly if faulty power is occurring. Test the +5V rail (better with an oscilloscope) prior to blame memory chips!

16 January 2011, 06:42	#17
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	Analogic or digital? Put the analogic/digital on AC measurement (sic!) on the best possible measurement (up to ~2V on digital) and read the ripple: it must be lower than 0.05V. With an oscilloscope things are easier to read, but even an ordinary meter can do wonders when you know how to use it.

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