exxos's Atari, Amiga & retro forum

BrettRogersUK wrote: 24 Nov 2021 00:31 Just so I'm clear on things on the exxos board there a SEL and GND I've connected these to a switch one to the middle pin of the switch and SEL to the other so when I switch it it wither stays gnd (off) or when the switch is in the SEL position it toggles the rom?

When the switch is open you get one bank, when close you get the other bank.

exxos wrote: 24 Nov 2021 01:08

BrettRogersUK wrote: 24 Nov 2021 00:31 Just so I'm clear on things on the exxos board there a SEL and GND I've connected these to a switch one to the middle pin of the switch and SEL to the other so when I switch it it wither stays gnd (off) or when the switch is in the SEL position it toggles the rom?

When the switch is open you get one bank, when close you get the other bank.

Thanks,

That's what I thought. I'll have another look at my motherboard in the morning with fresh eyes and see what I can do to rescue it.

Thanks again everyone for your help. Much appreciated.

I'll post some pics tomorrow of what I've done.

Regards,

Brett

BrettRogersUK wrote: 23 Nov 2021 23:58 I've connected wire from the pin that I traced it back to on P103. I've connected the pin on P103 to pin 4 on the 28 pin IC on exxos board on the LO and also connected it through the same pin on the HI side. There aren't any more traces for that that I can see.

That won't work..you have to repair the track going past the via you broke. Not just reconnect the ROM pin. You still have a broken track under the ROM which needs repair as others have said.

Hi All,

Right, start from scratch.

I had to desolder my HI and LO chips from my motherboard as they weren't in sockets. I have the Exxos Dual Tos board with TOS 1.62/2.06 in it.

It's a very well made board and went together quite well. I managed to desolder the HI chip and all was good. I did the LO chip and when I was taking the chip out the board a part of the track came up with it (See pic below highlighted pink) the piece of track that's missing I've identified as going to a pin on part P103. Pin 4 on the HI is connected to PIN 4 on the LO and this then runs down the bottom of the board on the top side to a via that goes to the underside of the board and then runs across the underside to P103. So what I've done is connect a small gauge wire from P103 to Pin 4 of the LO and then connected a smaller piece of wire connecting Pin 4 of the LO to pin 4 of the HI.

This should bypass the broken track on the topside of the board and should make everything work as normal. However, I'm just getting a white screen when I boot it up. Nothing else comes on the screen.

However, I think I can now see where I've gone wrong. On the track going from the P103 there is a via in the track there. So maybe what I need to do is place the wire after that via on the side where the track is broken on the topside to complete the circuit instead of going directly from P103.

Thanks,

Brett

If you haven't joined the purple tracks you've indicated on the image and just fixed what's on the underside, it won't work, especially if there is a via and tracks on both sides. You must fix all the tracks, both sides.

The damage on the top can be fixed with a bodge wire underneath as well, you just need to trace where the tracks go to and join them up, making sure that you pick up that damaged pin along the way.

rubber_jonnie wrote: 24 Nov 2021 09:04 If you haven't joined the purple tracks you've indicated on the image and just fixed what's on the underside, it won't work, especially if there is a via and tracks on both sides. You must fix all the tracks, both sides.

The damage on the top can be fixed with a bodge wire underneath as well, you just need to trace where the tracks go to and join them up, making sure that you pick up that damaged pin along the way.

I think there's a misunderstanding. There isn't any tracks broken on the underside of the board. What I've done is simply remake (with wire) the tracks that are on the topside ie. The one that is broke, and put that on the underside instead of having any unsightly wires trailing on the topside.

The bit I broke off on the topside has been replaced with a bit of wire underneath ie. Pin 4 LO to Pin 4 HI and then a wire link from where I traced it to to remake that part of the circuit.

BrettRogersUK wrote: 24 Nov 2021 11:06

rubber_jonnie wrote: 24 Nov 2021 09:04 If you haven't joined the purple tracks you've indicated on the image and just fixed what's on the underside, it won't work, especially if there is a via and tracks on both sides. You must fix all the tracks, both sides.

The damage on the top can be fixed with a bodge wire underneath as well, you just need to trace where the tracks go to and join them up, making sure that you pick up that damaged pin along the way.

I think there's a misunderstanding. There isn't any tracks broken on the underside of the board. What I've done is simply remake (with wire) the tracks that are on the topside ie. The one that is broke, and put that on the underside instead of having any unsightly wires trailing on the topside.

The bit I broke off on the topside has been replaced with a bit of wire underneath ie. Pin 4 LO to Pin 4 HI and then a wire link from where I traced it to to remake that part of the circuit.

Ok, then that makes sense.

I would do a continuity test on all the lines running between the ROMS to be sure they are all good and make sure your repair isn't shorting.

I would also check the TOS Switcher install guide (I can't remember personally), to see if the 3 jumpers, W102, W103 & W104 need to be set in a specific way for the TOS Switcher to work.

Some additional info here: https://temlib.org/AtariForumWiki/index ... OS_Upgrade

I just looked at your picture again and that bodge wire seems awfully long.

I think you might be better picking off that address line somewhere much closer to the site of the original problem, as P103 is a pull up resistor and I'm not entirely sure that it's the best spot, plus it makes the wire very long.

I've gone on the VIA at the bottom of the board where the trace goes to the underside. Tacked the wire onto that and now I have continuity all along the line and to the two pins where I didn't before.

However, I've put it all back in the case and I turned it on and just got the white screen again. Turned it off and flicked the switch on the TOS board and then I heard a crackle and pop from over where the power supply is.

No physical signs of anything popped or burnt but there was a faint smell of something towards the rear of the power supply where the plugs plug into it.

Sounds like a bad power supply. You'll need to get that fixed before you diagnose the main board.