exxos's Atari, Amiga & retro forum

exxos wrote: 20 Dec 2022 15:17You cannot keep us in suspense that long :lol: :chairsmack:

Though if it is not those bus converters then I give up :lol: :roll:

Okay, then I've got bad news:


Result: no change on the resistances from DTACK to ground or 5v. And given that, unsurprisingly the same behaviour as this old post if I stick the chips back in.

Editing to add: I cleaned these up a bit with braid after the photos, and I definitely pulled off one of the pads in the process. (Sigh!)

Oh no :( aside from removing a chip I'm not sure what else to suggest. There is nothing on DTACK aside from a 2.2k to 5v with all chips removed.They not easy to remove as well :(

You could lift up the 2 legs on the regulator to cut power to the chips. But it needs someone with experience to remove the chips as track damage isn't going to be fixable else.

I have been following this thread and it’s been a big learning experience I expect in diagnosing the issue however at this point I would like to offer to have a look at the board for you.

For the benefit of the thread: I'm going to take @Icky up on his offer. I've got the board in a makeshift cardboard box on my way back to the UK for the holiday season. I'm looking forward to finding out what's up with this :lol:

stween wrote: 21 Dec 2022 23:14 I'm looking forward to finding out what's up with this :lol:

+1

:lol:

When I receive the board I'll continue the thread here on findings etc. Looking forward to the challenge and seeing another H5 born.

Board came through by Royal Mail this morning.

I have had a look over the board and the plan of attack is clean up the soldering on the underside. There are a few places where the joints aren't looking too good. On the top side there are two areas - #1 clean up the socket with a new one, thats just my OCD kicking in. #2 - I notice the resistors have been removed from the 3V3 / 5V translators as they were inductors but we do need resistors back in place for the busses to be functioning properly. Will upgrade these to 220K as we have found these to be slightly better than the original 100K we have previously used on these translators.


Once done with all these items then I will trace out that DTACK line mentioned in above thread.

Started to clean the board up and noticed the patch wire from one of the 68K ports #2 to the other port #4 on the A14 line. I couldn't understand why so I desoldered the socket and now I know why there is no via there the pad is gone. So Port #4 A14 wouldn't be working without that patch wire and I suspect the 3V3 bus A14 wasn't working. I'll patch this up with two wires one like you had from Port #2 to Port#4 A14 line and then down to the 5V <-> 3V3 translator chip A14.

3V3 <-> 5V translator 220k resistors in place and patch wire (not the neatest) in place (3rd from right) where the resistor pad was missing. Once tested and working i'll hot snot that in place so it won't get bumped or jolted in the journey home.

Is it working yet.. ?
Is it working yet.. ?
Is it working yet.. ?

:poke: