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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: sirkope on August 24, 2007, 04:45:12 PM
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Hello everyone,
Recently I've bought an amiga 1200 with a Blizzard IV 1230 MK turbocard with 8MB Ram but no math coproc. I used it with this way without any problem, till I bought an 68882/40MHz coproc. (68030 runs with 50MHz) I've started to use but the amiga had frozened about 20-25 min work. After 4-5 times I've bored it and removed the coproc. The machine seemet to work longer then with coproc. till it reached about the 45. minutes. Then it had frozened again. Since then it can't run with the turbocard, only if I remove/disable it.
When I start the amiga, the blue lines (turbo card self test) appeared, but when it turns to the hdd/fdd it stopped with a black screen, and thats it?
Any idea?
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Make sure the shielding inside the A1200 is not touching either side of the board. Sometimes when you are typing on the keyboard, it will press down on the shielding and ground out the 1230.
Bending the shielding up a little will fix this sort of problem.
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It seems to me, that it lays on the plastic edges of the case and doesn't "touch" anything else. Could the motherboard cause this? I've read a hack which solved some kind of unstability with an apollo turbo card.
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Hi, just try to clean the connector which connects the accelerator to the motherboard, this was the solution for me, i had the same problem when i bought my accelerator.
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It seems to me, that it lays on the plastic edges of the case and doesn't "touch" anything else
Check the shielding above the motherboard connector... when you push the card in, that shielding is above the card (between it and the keyboard) just above the card's connector. You can't see it at that point.
Sometimes it just barely touches, grounding out the card when you touch the keyboard.
It's hard to see but worth checking.
Had this problem nearly every time I installed an Apollo 1230.
My microbotics doesn't have as much exposed area to make contact.
Placing a strip of tape over the wires where they exit the black connector on the board is an quick way to test if this is the problem.
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I can't clean the edge, and the connector (yet) 'cause I haven't got 'contact spray' at home, (tomorrow I'll take one) but I've tried placing a strip of tape not just for the connector, but the memory bank part. But didn't work :(
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You can use isopropyl alcohol to clean the contacts (the same "magic potion" found on floppy-disk/CD cleaners).
Rub some with a smooth cloth.
That's it.:-)
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I've cleaned both, but doesn't work :(
Im afraid some part of the card had overheated :(
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Hi,
stupid question, do you have a SUPER PSU that bring you more than 100W or do you use the A500 (50/60W) PSU ? ;-)
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I'm pretty sure you had fried the coprocessor (40Mhz) when inserted it in board (buy a 50 MHz version, '882 are very sensible to overheat).
Did you install some kind of FPU library on your Workbench (in that case, remove the lib will do the trick)?
Try also remove the battery from the board for a while to "erase" it's memory (I'm noticed the batt is soldered)...
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Hi,
I've heard that the original PSU of amiga 1200 is hardly enough for the machine itself even if you install additional equipments. So, because I've bought it without PSU, the first thing was to buy an amiga 500 PSU. I've never heard anything about SUPERPSU.
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Probably you are right, but I couldn't check my 68882, but I've bought as an 40MHz one tested 50MHz also from Vesaila Computer.
But the card crashed after that I removed the 68882.
No, I haven't install any FPU library, or at least deliberately.
I'll try remove the battery at afternoon.
Thanks the ideas.
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im running my 882/40 clocked at 50mhz for many years, never had a problem
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I've run it without 68882 several times with no problem at all. But after I've installed the FPU, it seemed to me that the card overheated after 20-25min, and the machine reseted, and start to "jerk" the video signal, and generate strange noises. It was very scary. But a few minutes cooling, it can operate again normaly for another 20-25 minutes.
After 4-5 times I've bored it, and removed the FPU. Then it can operate about 40-45min, when suddenly the same effect occured, but after it the card stopped work at all. :(
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A new idea came up my mind, I haven't tested yet:
If I push both of mouse buttons, than turn on my amiga, a screen come up, where I can choose between booting devices, etc. Also has a page where I can see the installed equipments on the expansion port. I wonder if I see anything here ....
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Hi, by SUPER-PSU I meant a good and strong PSU that deliver more than 4.86v for 5v under heavy use. If not, it will crash.
I have dying A500 PSU after i use them with my B1230-IV+FPU+SCSI+2x128mb.
At centisible, a 68882/50 cost around 25/30 euros...
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I'm not sure I could remove the battery but I "wreck" the brown tape around it. But still not working...
My PSU:
C= Commodore
Power Supply A 500
P/NO. 312 503-03
Input 220V~50Hz 0.4A T315mA T40/E
Output 5V 2.5A
12V 1.0A
-12V 0.1A
One more thing, maybe important:
When I used the turbo card without FPU, I connect the amiga with an a520 or a SCART cable to the TV. When I've installed the FPU, I only switch it on to check it's working.
One of my dream to get a scandoubler for the 1200, but the ebay ones recently selled ~140$ which is too much for me.
At once I've read an article about an RBG -> SVideo converter, and because I could buy the converter chip, I built an external converter with it, and - I've supplied with the amiga RGB port +12V pin. The circuit use about ~46mA, and when I test, and later use it the turbo card was installed. So I used an amiga 1200HD with an 1.6GB HDD, a Blizzard 1230 Mk IV turbo card, a 68882 FPU, 16MB Ram, and an external converter unit supplied from the machine.
But now, when I test I don't connect any monitor or TV, just switch it on, listen the HDD and watch the HDD Led, and if no HDD activity, I switched of.
When I try it without the card, HDD works, and system loads.
But some strange behaviour occured a few days ago, the machine hadn't operated about a month or two, and when I swithed on the HDD had a strange noise. So I decided to disassemble the machine, check the IDE cable, usually it works. But after I assembled it and wanted to switch on, it didn't worked, Even the power led. So I tought, my PSU cracked, and I wanted to measure the voltage levels, but because my voltage meter's battery runs out of charge, I couldn't do it. Next day I disassembled the machine more accurately, and after it started to work. And it works till then... Strange..
Anyway: I have an another A500 PSU, at my workplace, tomorrow I'll bring it to home to try it.
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If I was you, I'll toss away those underpowered original PSUs and use this hack instead:
(http://www.rabayjr.com/Amiga/Fonte_Amiga_3_resize.JPG)
Here is the external view:
(http://www.rabayjr.com/Amiga/Fonte_Amiga_2_resize.JPG)
Where:
Preto = Black
Vermelho = Red
Marrom = Brown
Amarelo* = Yellow
Branco = White
* The guy who makes this make a BAD mistake. He puts the shield on the +5V line.
Instead of this, put the yellow wire (shield) on ground (with the black wire). Do not put the shield wire in anything else (like the PSU ground itself).
Any old peecee AT-PSU works.
Just one more tip: peecees PSUs must have the "power good" (PG on the board) wired to +5V line in order to properly work.
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Input 220V~50Hz 0.4A T315mA T40/E
Output 5V 2.5A
12V 1.0A
-12V 0.1A
2.5A is the puny one; the better do 4.5A
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Amiga 600 has a power supply for 5V/4.5A, probably I should buy one?
All my a500 PSU working well so I'm regret to cut the plug from it. Otherwise it's hard to find a kind of plug.
Koniconn has one 171-4405, Beckwith Electronics sells a Power Dynamics DP-215 ones.
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I had your problem a long while back, to get rid of it, I used a cotton bud and used some some CD lens cleaner and that done the job.
Mike.
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zipper wrote:
Input 220V~50Hz 0.4A T315mA T40/E
Output 5V 2.5A
12V 1.0A
-12V 0.1A
2.5A is the puny one; the better do 4.5A
I've tried with an another amiga PSU: 60W, 5V/4.3A, but still not working
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swift240 wrote:
I had your problem a long while back, to get rid of it, I used a cotton bud and used some some CD lens cleaner and that done the job.
Mike.
I've already cleaned it, using contact spray and ear cleaning sticks. Although only through the expansion slot.
At the weekend I'll disassemble it more to reach the whole space.
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sirkope wrote:
Amiga 600 has a power supply for 5V/4.5A, probably I should buy one?
All my a500 PSU working well so I'm regret to cut the plug from it. Otherwise it's hard to find a kind of plug.
Koniconn has one 171-4405, Beckwith Electronics sells a Power Dynamics DP-215 ones.
You don't need to cut anything, simply dessolder the cable from the orig. PSU and solder it to the new one.
Works like a charm. :-D
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@rkauer
* The guy who makes this make a BAD mistake. He puts the shield on the +5V line.
Is that a fact?
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Don't know,I haven't check it jet. Rkauer just suggest me a method converting an ATX PSU to support my amiga. Also he warned me, that there is a mistake in it that I should avoid.
TjLaZer wrote:
@rkauer
* The guy who makes this make a BAD mistake. He puts the shield on the +5V line.
Is that a fact?
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sirkope wrote:
At once I've read an article about an RBG -> SVideo converter, and because I could buy the converter chip, I built an external converter with it, and - I've supplied with the amiga RGB port +12V pin. The circuit use about ~46mA, and when I test, and later use it the turbo card was installed. So I used an amiga 1200HD with an 1.6GB HDD, a Blizzard 1230 Mk IV turbo card, a 68882 FPU, 16MB Ram, and an external converter unit supplied from the machine.
Ouch I wrote false info: not from +12V, I supplied from 23.pin (5V/100ma)
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The +12V from the RGB port is "protected" by a resistor. Currents over 30mA can drop the voltage too much.
Catch the +12V from another source (paralell port, external floppy, etc).
+5V is protected in same way. But IIRC, the pin can supply up to 100mA. But with voltage drops (the very same as +12V line).
Feed your external devices in other way, I advice you.
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I do not use +12V, only 5V.
I went to a kind fella this afternoon to try the card in a different a1200, but still didn't work. :(
I left it at him to try a few thing with it.