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So you need to reset for it to boot? What's the non-booting screen look like?Forgottenmyname wrote: 13 Oct 2018 13:18 yeah it was me, still messing around with that but just takes 1 reset and off it goes for now.
White centre with pale yellow background (overscan)troed wrote: 13 Oct 2018 18:08
So you need to reset for it to boot? What's the non-booting screen look like?
Same behaviour with/without RAM card connected, and verified the RAM card is working in a Falcon. Need to start looking at ROM access ...troed wrote: 04 Nov 2018 14:15 (yeah my progress is really slow, too many things ... )
Just verified that the issue isn't with reset at least. That signal works as it should. The cause for white 60Hz screen at boot is something else.
(I'm used to just being able to quickly connect the LA to the pins of DIP chips, much slower to debug these sockets .. )
Yeah I was hoping to narrow it down a bit before doing that :) In general I have high trust in my soldering but something's clearly not right.exxos wrote: 04 Nov 2018 18:27 Might it be worth cleaning up the PLCC pins and fluxing the sockets and resoldering ? You should really be working :(
I would suggest you de-solder the power pins on the PLCC sockets, and resolder those at least.. not trying to suggest bad soldering, but it catches people out (even myself) because of the huge copper areas connected to GND and 5V pins.. pins look soldered perfectly , but they might not be..and metering doesn't always show bad connections because of very low current through the solder joints. I mostly end up holding a gas soldering iron to heat the "area" up around the pin, and solder as normal.. been having to do that on the STE booster boards on the gnd pins.troed wrote: 04 Nov 2018 21:41 Yeah I was hoping to narrow it down a bit before doing that :) In general I have high trust in my soldering but something's clearly not right.
Exxos has a good suggestion. I think I ended up going round the PLCC pins 3 times to make sure there was good enough joints. Most of my issues were down to joints. Even under a magnifier they look perfect but weren’t.exxos wrote: 04 Nov 2018 21:49I would suggest you de-solder the power pins on the PLCC sockets, and resolder those at least.. not trying to suggest bad soldering, but it catches people out (even myself) because of the huge copper areas connected to GND and 5V pins.. pins look soldered perfectly , but they might not be..and metering doesn't always show bad connections because of very low current through the solder joints. I mostly end up holding a gas soldering iron to heat the "area" up around the pin, and solder as normal.. been having to do that on the STE booster boards on the gnd pins.troed wrote: 04 Nov 2018 21:41 Yeah I was hoping to narrow it down a bit before doing that :) In general I have high trust in my soldering but something's clearly not right.
Not saying this is your problem, just making aware how easy it is to get tripped up by such things :)
Icky, did you use unleaded solder. Troed what did you use for solder. I know my attempts with unleaded solder years ago were disappointing and never made another effort to use it.Icky wrote: 05 Nov 2018 08:05Exxos has a good suggestion. I think I ended up going round the PLCC pins 3 times to make sure there was good enough joints. Most of my issues were down to joints. Even under a magnifier they look perfect but weren’t.exxos wrote: 04 Nov 2018 21:49
I would suggest you de-solder the power pins on the PLCC sockets, and resolder those at least.. not trying to suggest bad soldering, but it catches people out (even myself) because of the huge copper areas connected to GND and 5V pins.. pins look soldered perfectly , but they might not be..and metering doesn't always show bad connections because of very low current through the solder joints. I mostly end up holding a gas soldering iron to heat the "area" up around the pin, and solder as normal.. been having to do that on the STE booster boards on the gnd pins.
Not saying this is your problem, just making aware how easy it is to get tripped up by such things :)
The other area I found needed going over were the ram header pins and circuitry round there.
In the end I spent a good evening going over every joint with a magnifier and any slightly odd looking joint gave it another resolder.