exxos's Atari, Amiga & retro forum

Ok the problem should be somewhere else then.
Yes fixes are done. Will post some photos tomorrow.

Robson wrote: 01 Jun 2020 00:14 the DAC runs really hot. Can't keep my finger on it after 10-20 sec.

This accurately describes normal operation. It is pretty hot.

Using the diag rom at the moment but same with test cart.

Have you hooked up a null modem cable to look for serial output?

derkom wrote: 01 Jun 2020 07:14 Have you hooked up a null modem cable to look for serial output?

Yep, no activity at all. I did check your build post too.
Taking some photos in a minute.

Not the cleanest yet but washed in ipa once.

Robson wrote: 01 Jun 2020 07:57 I did check your build post too.

Good, because I think I made most of the mistakes possible. :lol: But I did get there in the end!

I'd agree that a serial port connection with a diag card is a good way to go. White screen can be a lot of things but with my H4 it was a ROM problem. I probably mentioned I'd forgotten to install the LS11 and had to fit it last thing of all, but ended up having to do a bodge wire in the end because one of the pads just wouldn't take solder.

I got a plain white screen. It also says you're generating video.

In order to bypass the onboard ROM, I put the ROM on the IDE interface instead, which bypasses all of the onboard ROM circuitry. If it works like that then you have a problem with the onboard ROM that you'll need to troubleshoot.

If you can get your IDE card finished it can be a good ROM troubleshooting tool. Incidentally, you don't need a hard drive attached, just the card built and the ROM in the socket.

"I got white screen & no other output (on serial and such)"

I meant that it was hooked up to serial when saying this. Not even garbage shown.
Tried your TOS too (in 1.04 mode). Will check the IDE board way as well.

At the moment the RAM is something I'm not 100% sure about, just found that module in my box (and its pair here) but will have to get the other tools out later to see what's happening on the busses.
Clocks and Vccs are ok.

Robson wrote: 01 Jun 2020 11:07 "I got white screen & no other output (on serial and such)"

I meant that it was hooked up to serial when saying this. Not even garbage shown.
Tried your TOS too (in 1.04 mode). Will check the IDE board way as well.

At the moment the RAM is something I'm not 100% sure about, just found that module in my box (and its pair here) but will have to get the other tools out later to see what's happening on the busses.
Clocks and Vccs are ok.

So a white screen on the Atari and nothing on serial? I got exactly the same on my H4 with a ROM issue (Bad LS11 connections). If you can get the IDE board completed and it works with the ROM on that, I think that would be a good step forward as you know where to start looking.

Also, on my H4, when the onboard ROM didn't work, neither did my diag cart, which is probably why I saw nothing over serial. My diag cart has an LED which flashes when booting the cart, and it was off when I had my LS11 problems. The IDE board is a great way to make sure the CPU and ROM are talking, though you will need a DIP packaged 68K for the IDE board too, so the PLCC CPU will need to be pulled.

BTW, not sure what res you're testing in, but I've found hires to be a bit unhelpful as you can just get a black screen, whereas with lores, you see the borders, and if the middle is black, you have a RAM problem most likely. If you have a partially black screen with corruption, it could be RAM, or as I've seen before, data line problems.

I'll check those connections and the IDE board way as well. I don't have a 50pF cap...that's all I'm missing for it.