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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Dr_Righteous on August 29, 2003, 10:33:33 AM
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As I've mentioned before, I have a couple of A1200 boards I'm trying to get running.
The one board I have that boots at all seems to have a problem stemming from Paula... FDD unrecognized, DF0:?????? on the WB desktop...
Paula is getting quite warm in a short period of time... A few minutes later, black (sometimes messed up) screen, system locks.
I've checked the voltages with a DVM, and everything looks fine as far as that goes, so my guess is it's Paula herself.
My question is twofold:
1. Does anyone know an inexpensive method of extracting and replacing the 13x13 PLCC?
2. Will the A1200 run without Paula, if I were to just cut it off the board for the time being? (Obviously I'd lose FDD, Mouse/Joystick and Audio... But I can get by with a serial mouse and maybe get a Catweasel)
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I only know the answer to question 2.
No! :-P
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Sounds highly likely that Paula has problems. Might be worth changing the CIAs as well, as they may have been damaged the same time as Paula. They are also responsible for some floppy I/O.
The system will definately not boot without Paula, or the CIAs for that matter.
As for changing the PLCC device, personally I could do it blindfolded, but assuming you don't have access to SMD rework tools, a cheap alternative is to use a pyro pen. Get a butane powered soldering iron and remove the tip so you have a mini flame thrower :-)
I might add this is a bit tricky if you're not well experienced, and it's easy to put too much heat into the PCB and lift tracks. Practice on an old PCB first.
Hold the pyro pen approx 10cm away from the device and heat it in a continuous circular motion. Apply gentle upward pressure to one corner using a steel spike or screwdriver, and you'll find it'll suddenly lift off.
Use solder wick to remove all solder from the new IC and the PCB. Run a bead of solder paste over the pads on the PCB, position the IC correctly and gently heat it on until all the solder melts smooth and shiny. Check carefully for solder shorts and unsoldered pins. Wick off solder or apply more paste as required.
If you don't have solder paste, get some extremely fine solder (0.2mm or less) and a tiny soldering iron and hand solder it.
Hope that helps,
Anthony.
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Just buy yourself an Amiga 4000 and get rid of those Amiga 4000 wanna-be 1200s. I mean, why use a toy, when you can have the real thing?! :-D
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Just buy yourself an Amiga 4000 and get rid of those Amiga 4000 wanna-be 1200s. I mean, why use a toy, when you can have the real thing?!
If you have nothing to contribute go play with your superior A2000.
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@Piru:
Lighten up, PLEASE.
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If you know you're gonna remove it and not use it again, one way of getting it out is by cutting the legs and then desoldering those one by one afterwards.
Another way would possibly be to bend a paperclip so it will touch all legs simultaneously, then solder it onto each leg before heating up the whole thing and lifting up the IC with a sucking device (possibly a trained girlfriend ;-) )
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Just buy yourself an Amiga 4000 and get rid of those Amiga 4000 wanna-be 1200s. I mean, why use a toy, when you can have the real thing?!
because the a4000,s are the worst amiga,s for reliability everyone must have been repaired at least ounce by now besides the a1200 is cheap and much better machine. :-)
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You could send your A1200 motherboard to an Amiga dealer to fix it, but it will be expensive.
Or buy a replacement A1200 motherboard.
I also agree with amigamad:
because the a4000,s are the worst amiga,s for reliability everyone must have been repaired at least ounce by now besides the a1200 is cheap and much better machine.
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because the a4000,s are the worst amiga,s for reliability everyone must have been repaired at least ounce by now besides the a1200 is cheap and much better machine. :-)
Well, I can`t speak for other A4000 owners, but the only thing I`ve done to mine is replace the battery before it had the chance to leak.
One of my 1200s had to be repaired under warranty within 3 months of getting it (bad floppy drive)
My other 1200 had to have the timing fixes done to work properly with the accelerator card.
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@Castellen
Thank you for the serious response...
I would love to get my hands on some SMD equipment, alas I haven't the funds at the moment.
I think what I'll try is cutting the legs off with my Dremel and desoldering them one-by-one... Then solder in a 52 pin PLCC socket.
I'll definately have a look at the CIA's tho... I didn't even think about checking them out while I was at it.
On slight tangent... I ran across this (http://www.usbmicro.com/odn/documents/46.html) method of creating a hot air pencil, as opposed to the "flame-thrower" approach... It sounds feasable. Any thoughts?
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I managed to remove the 20 pin video encoder chip with a regular soldering iron and a dental pick... got the replacement resoldered with a fine iron. Not that it fixed the problem... but that's another story. :-/
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Dental pick? Did you use the iron to heat the pick or just pull the leads up off the board?