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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: HellCoder on July 07, 2004, 01:33:00 PM
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Hi all...
Currently I've got an A1200 equipped with an Blizzard1260/50MHz and SCSI. It was very very stable for a few years but now... it crashes all the time.
Normally when you turn on the computer you would see the rasterline-flashes incicating the card is running. Sometimes it stays black, sometimes the flashes stop halfway and leave a black screen and sometimes it boots perfectly untill I put a coffee-mug on the desk orso...
It all indicates a loose connection somewere.
The card was send to repairs, they claimed to have done something with it but problem remains.
The powersupply is a modded PC supply giving plenty of power.
Disbaling the SCSI (remove) doesn't help
Switching RAM doesn't have any effect
Is there anyone who had the same problem and can tell me what to do ? I can modify the board if I want to coz I'm an electrical engineer but don't know were to look... :(
It's all inside an A1200D, leaving the CPU-cover open and no other hardware connected....
:-? :-?
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Oh,.. I tested it on several A1200's, all the same!
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Hi there,
Take a look at the clock battery surroundings,and see if you notice any leakage from the battery. Any corrosion can destroy the board. These boards are multilayered, and the acid from the battery leakage can get in the inner layers of the board and blow all out.
Would be even better to check the battery voltage with and multimeter. If it's below the 2.3V border, just replace it.
Besides the battery problem, you can have a "cold soldering" (as we technicians knows it here in Brazil) problem. Some of the solderings can be loose or cracked. So if you do have an AC isolated soldering iron, you should try to patiently resoolder everything you can reach.
Right now these are the things that comes to mind for your problem.
Good Luck, and sorry for my bad english.
Marcelo Pires.
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Hi there,
Take a look at the clock battery surroundings,and see if you notice any leakage from the battery. Any corrosion can destroy the board. These boards are multilayered, and the acid from the battery leakage can get in the inner layers of the board and blow all out.
Would be even better to check the battery voltage with and multimeter. If it's below the 2.3V border, just replace it.
Besides the battery problem, you can have a "cold soldering" (as we technicians knows it here in Brazil) problem. Some of the solderings can be loose or cracked. So if you do have an AC isolated soldering iron, you should try to patiently resoolder everything you can reach.
Right now these are the things that comes to mind for your problem.
Good Luck, and sorry for my bad english.
Marcelo Pires.
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Actually I removed the battery coz that fixed my 030 card one time. So it's not located on the board anymore. It didn't change anything though so I might have to look at all the solderings...
Thanks!
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Marcelo,
The Blizzard line of accelerators come with a coin type (Lithium) battery that is not rechargeable and doesn't leak, unlike the ones used in big-box Amiga computers (except A4000T).
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Hello,
A few things to try,
1) Connect a multimeter across pins 14 (+V) and 7 (0V) of one of the 74 series TTL devices and measure the voltage. It should be within 5% of 5 or 3.3V (not sure what the logic is).
2) Clean the A1200 CPU slot with isopropyl alcohol and use contact cleaner on the accelerator slot.
3) Check the voltage output of the LT1585 3.3V converter.
That's all I can think off for the moment.
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Hello, Oh, I have had this problem with my dad's A1200 at least twice. My un-educated guess is that the accelerator is not making contact with the edge connector of the A1200 properly. The '030 card in my dad's Amiga seems to 'hang down' a little. I tried the contact cleaner, etc., with no luck. I ended up using a rolled up piece of paper to hold the accelerator parallel to the A1200 slot, i.e. in straight. Funny, I have seen this on 2 different A1200's (desktop) with two different accelerators, but not on my Power Tower A1200, where the Accelerator is oriented up, i.e. gravity pulls it down towards the accelerator connector of the 1200... Hmmmm.....
Hope this helps, Marc
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Did you change some software? You could try to reinstall the workbench and the 060 libs.
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Hi HellCoder,
try to insert the card, not full inserted (a couple of mm less).
If it is a mere mechanical lacks of contact, a cleaning isn't enough.
Ciao