exxos's Atari, Amiga & retro forum

I ordered a birdseed version, and I've got it assembled, but it's not working.. (Just black screen.)

I'm attempting to double check all my connections using openboardview, but I'm wondering if it's correct at all?
I'm using the brd file from the github page, and it shows a3 connected as the ground plane, and a15 tied high.

tf536 rev 2b.

Thanks.

Also, how hot should the cpld get? I'm using a pi to program, and it verifies correctly, but the chip is very warm to the touch.


I do have a 100mhz clock, and for tools, a 100mhz 4 channel scope, but no logic analyzer.

The CPLD is not normally very hot. You have most likely a bridge or two between some of the pins. This is the issue in almost all of the cases.
Check with for continuity if you have a multimeter handy.

You would also need Kickstart ROM 2.05 or higher to boot from the IDE header.

It’s 99% a soldering issue.

People cry that their soldering is perfect but I’ve even had @chucky agree… is 99% a soldering issue. You cannot see all soldering issues without magnification.

In very very rare cases I’ve had a bit of brass flux break off and get under a chip. And about 1 in 500 boards have a fault that jlcpcb don’t catch

I checked all the connections for bridges and continuity using a microscope and a multimeter with very sharp leads.

My method is one lead on the top on the pin on the chip and then the pad on the board, if it has continuity, then I move the lead from the pad to the next pad down, check for a short, then move the other lead to the next pin, lather, rinse, repeat.

The only 2 pins next to each other that have continuity are 89 and 90, which are supposed to be. (GND....A3 on openboardview... ?????)



I'll go through all of them again, pushing hard sideways on the pins to double check for a good joint.

But, my original question still stands.. Is there a correct brd file for the 2b version?

Thanks.

Also, what's the bare minimum parts the board can boot with?

CPLD and CPU? or does it need the ram installed?

ok. The board works. Around 500 people have built one. Every time there has been an issue its bad soldering or faulty components. there has be a single case of a bad board from JLC....

The ram doesnt need soldered on but that wouldnt stop diagrom booting.

I'm not doubting that your board works, I'm just trying to find out where I've screwed up.

The CPU I'm using is A Motorola Branded XC68030RC50B that I've had in my parts stock for 10 years or so, and the only other 68030 machine I have is a Mac SE/30, and it runs the mac fine (At 16mhz...)

I don't have a copy of diag rom, I have kickstart 3.1. And I've tried on a rev5 and rev6 motherboard.
I have a rev 8 that I haven't tried yet, but I don't know if that would make a difference.

I guess I'll remove the buffer chips first and see what happens.

dabone wrote: 27 Jun 2021 20:53 I'm not doubting that your board works, I'm just trying to find out where I've screwed up.

The CPU I'm using is A Motorola Branded XC68030RC50B that I've had in my parts stock for 10 years or so, and the only other 68030 machine I have is a Mac SE/30, and it runs the mac fine (At 16mhz...)

I don't have a copy of diag rom, I have kickstart 3.1. And I've tried on a rev5 and rev6 motherboard.
I have a rev 8 that I haven't tried yet, but I don't know if that would make a difference.

I guess I'll remove the buffer chips first and see what happens.

even with the worst possible cpu it will still boot diagrom (because the CPU will run at 7Mhz). if you're not using diagrom then do that before anything else.

Ok, success! (Kinda.)

Removing the buffer chips finally got me the rainbow boot screen.
I then redid one of the rams and got amikit diags running, so we now have boot and ram!


I ordered 74VHC245PW for the ide buffers, was that correct?