Amiga 1200 Mobo repairs?

[CU_AMiGA]

Hello,

Disaster struck for me yesterday. I think my A1200 mobo has finally packed up. I know that several chips in the Amiga do lots of tasks between them, so i think the problem is the Gayle chip has blown. Here is the problem i get:

DF0: Is not recognised (DF0: not DOS disk) -edit- DF1: Is fully functional though.
The FDD light is on for about 10 seconds during boot up when it shouldn't be.
Booting up is MUCH longer.

Thankfully, me being a person with my status (God like) i have a couple of spare A1200 mobos to use, so i will be busy fixing one of them in tonight!  :roll:

I would just like to know what could have possible caused this fracas and if the mobo itself can be repaired or not, or is it destined for the bin! :-(

Regards,

[amigamad]

DF0: Is not recognised (DF0: not DOS disk)

That could be the drive, i have one which dont detect disk changes will only read a disk if inserted before power is turned on . :-)

[downix]

I had an identical problem.

I thought I'd blown a CIA.  Turns out it was a floppy drive on the way out.

[CU_AMiGA]

Okay i will have a look at the floppy drive and cables. Thanks. But if the worsed come to the worsed, then how much would repairs cost? Or a new floppy drive.

Regards,

[lorddef]

I have a spare a1200 floppy drive somewhere at home, you are welcome to it if you need it.

[4pLaY]

it wouldent be worth it to fix it unless you do it youreself or get a friend to do the job free! getting a used A1200 or even brand new A1200 magic pack is cheaper then getting someone to look at it! keep it for spares or donate/swap it with someone that might need the parts.

[doctorq]

DF0: Is not recognised (DF0: not DOS disk)

The FDD light is on for about 10 seconds during boot up when it shouldn't be.

Booting up is MUCH longer.

Well, if I were you I would check the floppy and floppy cable at first, before putting in a new mobo.

The longer boot time is because the computer can't find the diskdrive. If I disconnect my internal diskdrive on my machine, it takes about 15 seconds before it even starts booting off my hdd.

[twizzle]

if you need spare parts go to analog computers
tel  020 8546 9575   surrey

they do an exc mobo £50  or a new one  £100

i have been having the same problem  myself
so i bought a new mobo - hdd - hdd floppy drive
- powerflyer - cdrw - 3.1discs

and i still have the problem
plus software crashes

and i cannot get any one to help sort  it  out.

if you find the problem please let me know
mike

[Castellen]

As the others said, it sounds like the computer is not seeing the floppy drive.  Try a known good drive and 34 way cable to eliminate those.

On power up the system polls the drive select lines from 0 to 3, and if any drive is on that ID, it pulls the ready line low at the same time as it's polled so the system knows it's there.

In the A1200, CIA U8 outputs the drive select lines (_SEL0 to _SEL3) so if these are not being generated, U8 could be faulty.
To check, put a diode between _SEL0 and ready (_RDY) with the cathode towards _SEL0.  Power up the system and see if it still takes ages to "detect" the floppy drive.
If so, there could be a possible fault with U8.
You can also check this with a digital storage scope if you have one laying around :-)

You can get replacement CIAs fairly easily, but they can be expensive.
U8 can also be tested by swapping it with U7.  If the parallel port no longer works correctly (bit 3 dead) it proves U8 is faulty.

If you get REALLY stuck, you can send the MB to me in NZ for repair :-P

[voytech]

amigamad wrote:
(..) i have one which dont detect disk changes will only read a disk if inserted before power is turned on . :-)

Did you checked those tiny microswitches in your drive? (there should be min. 2 of those, or 3 if you have Panasonic drive). You should check if any of them aren't broken, and if yes, change them for new ones (soldering ability required :-D ), or if you can't find any (for example in old/unused pece floppies), you can attach some cables and get a standard switch hooked to your drive - if you want to tell your miggy that you changed the disk, just reset this switch, and will read new disk in drive..  :-D

[CU_AMiGA]

Thanks for the replies,

I cleaned out the FDD connector and reconnected everthing back up, and it all works okay now. Maybe i shopuldn't panic next time this happens!  :oops:

[amigamad]

Did you checked those tiny microswitches in your drive? (there should be min. 2 of those, or 3 if you have Panasonic drive). You should check if any of them aren't broken, and if yes, change them for new ones (soldering ability required

Mine is a teac drive was working when i got it.

[lempkee]

my cia chip(s) are blown , alot of games and tools doesnt work + my boot is sometimes looooooong...

anyway i need a new mobo asap zulu....doesnt even have a spare one.... YIKES:)