exxos's Atari, Amiga & retro forum

Very true @exxos and it was because this was the most Reliable board that I have with the smt chips is why I sent it to zChris.

Ive measured the MAD lines and they pulsates with 2Mhz to 4Mhz according to the oscilioscope.

/zChris

zChris wrote: 19 Aug 2021 19:20 Ive measured the MAD lines and they pulsates with 2Mhz to 4Mhz according to the oscilioscope.

/zChris

So it sounds like the MMU is working which is good.

This might be time consuming but try this, remove the dma and see if the cpu /halt line now stays high after the reset.

PhilC wrote: 19 Aug 2021 19:36

zChris wrote: 19 Aug 2021 19:20 Ive measured the MAD lines and they pulsates with 2Mhz to 4Mhz according to the oscilioscope.

/zChris

So it sounds like the MMU is working which is good.

This might be time consuming but try this, remove the dma and see if the cpu /halt line now stays high after the reset.

I'm not sure i did it right but this is what i did. I removed the chip that's on the "BAD DMA" socket, that's the DMA right? Then i measured HALT line, pressed the reset, it goes low, released reset and it goes high after a short time.

/zChris

@zChris So the Glue is halting the system.

In one of your photos it looks like there is a bridge on one of the GLUE pins, can you take a clear close up photo of it please.

Yeah sure
EDIT: Hmm cant make the image clickable to view the big one for some reason. Hope this work.
/zChris

The pins next to C21? Pin 69-70 (A12-A13) looks joint.

zChris wrote: 19 Aug 2021 20:55 Yeah sure
EDIT: Hmm cant make the image clickable to view the big one for some reason. Hope this work.
/zChris

@zChris - reason for the image not working is you need to place it in the post correctly. Instructions here - https://www.exxosforum.co.uk/forum/viewt ... =20&t=2357

I have done this for you already on that image.

DoG wrote: 19 Aug 2021 21:01 The pins next to C21? Pin 69-70 (A12-A13) looks joint.

Good spot @DoG - looks like solder blobs just nestling inside the pins of the SMT

DoG wrote: 19 Aug 2021 21:01 The pins next to C21? Pin 69-70 (A12-A13) looks joint.

I have done an ohm measurement on all the GLUE pins and none of them had connection to a neighbouring pin.

/zChris