Troed - progress

[troed]

yeah it was me, still messing around with that but just takes 1 reset and off it goes for now.

So you need to reset for it to boot? What's the non-booting screen look like?

[PhilC]

So you need to reset for it to boot? What's the non-booting screen look like?

White centre with pale yellow background (overscan)

[exxos]

The problem was the reset on power up delay wasn't enough, so he was having to power up, then press reset button to get it to boot. We pretty much solved that be increasing the cap in the reset circuit to a higher value (I put 47uF as the "new" value).

[troed]

(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 .. )

[troed]

(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 .. )

Same behaviour with/without RAM card connected, and verified the RAM card is working in a Falcon. Need to start looking at ROM access ...

Ah. /HALT is low.

[exxos]

Might it be worth cleaning up the PLCC pins and fluxing the sockets and resoldering ? You should really be working :(

[troed]

Might it be worth cleaning up the PLCC pins and fluxing the sockets and resoldering ? You should really be working :(

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]

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.

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 :)

[Icky]

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.

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 :)

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.

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.

[PaulJ]

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 :)

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.

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.

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.