Falcon030 Repair

[Darklord]

When looking through the parts Best have, I almost want to get a few of everything "just in case". :lol: You never know when these things will go out of stock, at which point repairing anything becomes a scavenger hunt.

Just remember his set of "rules"

If you have a customer ID #, have it ready.

As accurately as possible, know the part's name and part number.

He usually limits orders to 3 items at a time and a minimum price ($100? IIRC).

I've rarely had any issues with ordering from Best Electronics but a few have.

[jamesrhq]

I have heard of people having issues with ordering stuff in the past. I have to say I’ve had no issues personally. This will only be the second lot I’ve ordered, and the last was some years back, but it’s been extremely smooth and easy. Straight to the point and no messing. :) I ordered quite a few bits this time as I was needing to order some other parts anyway, it definitely helps to water down the super expensive USPS rates! :o I’m now going to be really impatient waiting for it to arrive… :lol:

[jamesrhq]

Ok, getting somewhere!

New VIDEL arrived, so I installed it. Nice clean job in the end, despite my cack handed essential tremor! I used a new set of GAL's I burnt and initially I just got a screen full of crap as you'd expet if the video hadn't been initialised. Checked the CPU, no activity. So I seemed to have gone backwards.

Backtracked to my original test setup which involved an original Atari set of GAL's, and what do you know, I got a black screen and CPU activity. Swapped the newly programmed GAL's in one by one until I found one which caused the machine to hang again. Verified it, fauilty. Tried programming it again, failed. Good old AliExpress parts... :roll: Programmed up a new one and now getting a black screen. Result.

Stuck in the diag cart, got some stuff happening then a red screen full of crap. Reset it, actually get diagcart running! Although it doesn't seem to be happy with my TOS version. I think this machine has 4.02 and the diag cart must want 4.04 as that's what it reports my other Falcon board has on it.

IMG_0237.jpg

So a step in the right direction. TOS 4.04 to be burt next to try and get a thorough test with diagrom. When diagrom hangs it actually hangs the CPU (dtack flatline), so I have a feeling the missing SCSI chip may somehow be causing this.

[mikro]

That Pre Burn-In message is actually a bit misleading. It just compares a byte in NVRAM with what it has in the cartridge ROM.

There are three ways to work around it:

- clear NVRAM: don't use tools which reset only known fields, a complete NVRAM reset is needed (CTRL+ALT+SHIFT+UNDO during memory test)

- update NVRAM: there's a secret key 'u' which can be pressed during the check -- that way the test will be skipped and new (current) value written to NVRAM

- use http://atariforum.team-yankee.net/viewt ... p=119#p119

[jamesrhq]

Ah! Is this in the realtime clock? That would make sense as this machine doesn't have one. Oddly enough I just swapped out the TOS ROM for the one in the working machine and am getting the same error, so that makes sense.

[jamesrhq]

Just found a keyboard, pressing U does something then returns me to the same screen. I see an error message complaining about the RTC just before it switches to this error screen, so it looks like I need an RTC to continue. Annoying I have one of the Exxos RTC replacements *somewhere*, but I ordered it a few years ago and have lost it. :o

[jamesrhq]

New RTC module arrived and installed, and what do you know, it works! The SCSI chip is missing, I have a replacement for that which I'll fit, but otherwise it seems to be functional! Amazing. :)

So I now have both a (seemingly) working NTSC and PAL Falcon PCB. I've been designing a case for them, so that's the next step...

[viking272]

Excellent, great news.
What sort of case are you working on? A clone of the current one or something a little more exotic?

[jamesrhq]

I have something a bit like a mega case in mind. I’ve got a rough design modelled up with folded / machined aluminium top and bottom sections and 3d printed front and back fascias. The 3d prints are a bit big for my 3d printer, though, so I’m going to have to print in two halves and join them! It will be the first time I’ve tried aluminium in my cnc machine as well, so hopefully it cuts ok. Just really need it for cutting out the holes for connectors, floppy drive, displays, etc, then folded to make U type sections. I’m planning on a custom floppy emulator as well using flash floppy and being able to specify a physical drive as well as an image from a memory card for A / B. Plus the mcu can then control the atx soft power, too. :) I figure if I’m going to do a custom case, I may as well go all out. I’ll post some pics tomorrow when I’m at the pc.

[viking272]

Case sounds pretty cool. What's the thickness of aluminium?
Would be interested in seeing photos when you have a moment/have progressed.