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Re: Falcon floppy problems

Posted: 25 May 2020 01:35
by Acsi
OK so an update although I wish it was better news.

The new Ajax chip arrived. I had already unsoldered the old one and installed a socket.

After testing the old chip in the socket I got E9 error's with the test rom and behaviour very similar to before removal.

Installed the new Ajax chip and get the same behaviour. :evil:

When it does boot to desktop it will not spin the drive motor still. So I suspect the Ajax wasn't at fault which makes me believe it's the combel which is SMT and beyond my abilities. Besides I do not have the skills or equipment to correctly diagnose the problem. :cry:

I believe I will now try to get a replacement at a decent price if I can find one.

Speaking of which there is one on eBay at the moment but it hasn't been fired up in 20years and is missing resisters (look like buffer ones only) but 450 euro for a non working board :o

Re: Falcon floppy problems

Posted: 25 May 2020 01:48
by exxos
Have yo checked the CS pin on the 1772 on a scope to see if it switches ? Also has the 1772 got power ?

Changed U35 ?

Re: Falcon floppy problems

Posted: 25 May 2020 03:30
by Acsi
Power yes +5.07vdc between pins 14 and 15

I don't actually have a scope which isn't helpful and no I haven't changed U35 which I note is SMT

Re: Falcon floppy problems

Posted: 26 May 2020 01:36
by Acsi
OK So I've order replacements for U35 and U19. Both seem to tie into the Ajax.

The U19 is easy for my skills but U35 will push them to the limits :?

Re: Falcon floppy problems

Posted: 10 Jun 2020 00:50
by Acsi
OK So I have replaced the resistor array and U35 and still the problem exists.
I have decided not to pursue this any further as I doubt I can replace U19 without damaging something.

Board boots occasionally requires a reset to get to the boot screen.

It will now be for sale if anyone is interested before I put it on eVilbay?

Re: Falcon floppy problems

Posted: 10 Jun 2020 05:45
by sety
PM sent