As near as I can tell, it looked like it is complaining about your 5101 RAM; I know you said yours was removed... I ran my test with it pulled, and it passed there. The second stint of flashing you're getting is to be expected- that is for the system7-only sound PIA.

Have you ever seen this board run? Was/is there battery corrosion damage? What chips are socketed, and have you replaced the 40 pin CPU, the ROM sockets (I know you said the board was converted to 3 ROMs)? I guess I'd poke around the 5101 socket, and make sure there are no shorts, especially if the 5101 chip was recently removed/socketed. An extra close once-over looking at any previous rework too.

If the board is behaving intermittently, I like to give them a little wiggle while they're powered up, to see if anything changes.. Please exercise caution here if you try this (don't try this at home) But, the idea is- if there's a change with a little wiggle, perhaps a cold/cracked solder joint, bad trace, etc. Nothing extreme enough to damage the board or break anything of course..

Also I'm surprised your relay isn't a bit louder, but- maybe they vary in noise? Perhaps others have some ideas too.

No, I have not seen this board work. The relay on the same driver board is a lot louder when I use a system 6 MPU from my Gorgar machine. There is no battery corrosion that I can see. The 5101 RAM is socketed and looks brand new. The CPU is socketed and looks new. I just replaced IC13 and socketed it with no change. There is no change when the board is flexed or wiggled at all. I have continuity at every pin on the 40 pin interconnect when checking to the next component downstream or upstream according to the schematics. I expected the flashing due to there being no RAM and this not being a system 7 board, I didn't expect everything to pass considering this board won't boot in the machine. Just wondering if I'm missing something obvious. I'll keep digging.

Thanks!

I wondered the same thing. I ordered the single rom adapter from Siegecraft. I’m hoping that it will tell me for sure if that was part of the problem. Also, with guidance from @cheddar, it looks like IC3 is bad. If I test it with my meter on diode mode and the red lead to ground, pin 13 (address line A11) measures .155 both in and out of circuit. IC4 and IC8 both measure around .600. Also, when I traced that circuit through the schematic, I saw that A11 also measured .155 at pin 14 on ic15. Once I pulled ic3, that measured .697.

The original video has been made private now. barakandl is there a way you can make it public or provide us with the link here?

I've pulled out a system 4 MPU that I started working on 13 years ago! (my how time flies). I originally wanted to use Andre's but have a Leon's in there. This video would be helpful to me to see how it works.

-Pat

Bump, I reference that video myself from time to time.

You can also try the Pincoder ROMs to help you troubleshoot:

https://pincoder.ca

Under the Support menu there is a link to "Community Usage Videos - YouTube" where a fellow pinsider (@troxel) has put together some quick videos for each test. The videos were done using the Pincoder Adapter:

https://pincoder.ca/index.php/2020/07/10/adapter-2020-06-23-0506/

But if you're already burning your own ROMs you can just download the images for free.

There are a number of test ROMs you can use that isolate parts from the ground up. You may be especially interested in the 12-flippers ROM as it allows you to test all of the PIAs at once.

The latest ROMs and their documentation are found in the Download menu.

Hope you find them useful