exxos's Atari, Amiga & retro forum

What do you get on the mono select pin ?

EDIT:

Looking at the diagram, I have it on RP1 pin 4, so check soldering there.. also check the mono_det pin to 5V and make sure you have 2.2K there...

Pin also goes to the MFP pin 29... so check soldering around the MFP in general...

exxos wrote: 20 Sep 2018 07:00 What do you get on the mono select pin ?

EDIT:

Looking at the diagram, I have it on RP1 pin 4, so check soldering there.. also check the mono_det pin to 5V and make sure you have 2.2K there...

Pin also goes to the MFP pin 29... so check soldering around the MFP in general...

Thanks Exxos.

I have been going over the board with a microscope to check everything out based on previous bad soldering. Will definitely check this out.

Unfortunately work has got in the way of my atari fun today. So will have to check later tonight.

Icky wrote: 20 Sep 2018 08:50 I have been going over the board with a microscope to check everything out based on previous bad soldering. Will definitely check this out.

Unfortunately work has got in the way of my atari fun today. So will have to check later tonight.

I've checked around the MFP wiring, don't see anything amiss there either... seems like 2 odd faults really, you machine tries to boot but no stable video, forgottonmynames machine doesn't boot but has stable video :lol:

I'm still checking stuff.. Think it got a bit confusing as I couldn't read the STF schematics and had to use the ST one instead, different part numberings , even some stuff seems wired up slightly different on the RAM buffers, just IO's swapped, but hard to read the STF circuit.. mix in some stuff came from the STE, MEGA ST, then other stuff was previous upgrades I've done like adding a 72pin simm (aka falcon RAM card) onto it for the RAM.. Its a pretty mashed up STF design overall , so makes checking a bit complicated :roll:

exxos wrote: 20 Sep 2018 07:00 What do you get on the mono select pin ?

EDIT:

Looking at the diagram, I have it on RP1 pin 4, so check soldering there.. also check the mono_det pin to 5V and make sure you have 2.2K there...

Pin also goes to the MFP pin 29... so check soldering around the MFP in general...

Hi Exxos you mention RP1 pin4 measuring as 2.2K to 5V but RP1 is 1K so is this correct?

Icky wrote: 20 Sep 2018 20:15
Hi Exxos you mention RP1 pin4 measuring as 2.2K to 5V but RP1 is 1K so is this correct?

ah yep...


I forgot I change my mind about 2.2K and used 4.7K instead for other packs...

exxos wrote: 20 Sep 2018 07:00 Looking at the diagram, I have it on RP1 pin 4, so check soldering there.. also check the mono_det pin to 5V and make sure you have 2.2K there...

Pin also goes to the MFP pin 29... so check soldering around the MFP in general...

RP1 is soldered correctly. Measuring 5V rail to MFP pin 29 its 1K as per RP1. However Measuring 5V rail to Mono Detect on monitor socket its 14K. Need to see why - just looking.

Icky wrote: 20 Sep 2018 20:40 RP1 is soldered correctly. Measuring 5V rail to MFP pin 29 its 1K as per RP1. However Measuring 5V rail to Mono Detect on monitor socket its 14K. Need to see why - just looking.

That is odd.. bad solder ? Even so, as long as the voltage is stable on the MFP, I don't know any way it can switch into mono...

exxos wrote: 20 Sep 2018 20:57

Icky wrote: 20 Sep 2018 20:40 RP1 is soldered correctly. Measuring 5V rail to MFP pin 29 its 1K as per RP1. However Measuring 5V rail to Mono Detect on monitor socket its 14K. Need to see why - just looking.

That is odd.. bad solder ? Even so, as long as the voltage is stable on the MFP, I don't know any way it can switch into mono...

I might be going mad but I just traced the pin 4 MONO DETECT on the monitor socket all the way to the VSYNC on the GLUE.

Icky wrote: 20 Sep 2018 21:04 I might be going mad but I just traced the pin 4 MONO DETECT on the monitor socket all the way to the VSYNC on the GLUE.

Can't see it going anywhere else....

exxos wrote: 20 Sep 2018 21:14

Icky wrote: 20 Sep 2018 21:04 I might be going mad but I just traced the pin 4 MONO DETECT on the monitor socket all the way to the VSYNC on the GLUE.

Can't see it going anywhere else....

So looking at pin 12 on the monitor socket which should be VSYNC is going to the MONO_DETECT.

I have the feeling the socket is wired wrong.