hello

[Gotang]

Hi guys

Really new to the st had a lot of systems over the years but always wanted a st for the midi and sequencer software.
I have managed to collect a few broken machines and picked up a mega st 2.
this is pulling my hair out i also have access to a mega st 1 i have tried all the main chips from one to the other and all work glitter glue etc
even the ROMs all working fine in the mega one but the mega 2 won't boot up keep getting corrupt white screen sometimes pink im thinking now it
must be a memory fault.
sort of hit a wall cant find much info on megas so any help would be greatly appreciated
also managed to pick up a ste and I've got that working that' was faulty memory but want to use the mega as music computer keep the ste for games lol
well that's my st side of the intro
my names Dave and im from Newcastle
and yes i swim like a fish lol

[PhilC]

:welcomewave:

I've got a couple of Megas myself too. One of the big problems they suffer from is memory failure, if you haven't already got one then try a diag cart but with the screen corruption its worth trying to clean all the sockets and chips with IPA first.

The other big problem with Megas is that they suffer from oxidisation or corrosion more than a regular ST.

Maybe try the above first and see how you get on.

[Tomswork]

:welcomewave:

My mega st2 had the same problem. Turned out to be the cpu was stuck in reset. Then the psu was bad and the memory and a bad rom socket. After that its run fine for the last 5 years.. I also had some of the sip resistor go like fuses.

I always start with the psu

Tom

[JezC]

:swave:
Welcome on board!

Hope you mange to sort out that Mega - I love my Mega 4 (almost as much as the Falcon, the original 1040 STF I bought in 1987 and the new H4) - I originally bought that STF with a mono monitor for University work & MIDI and music in general.

There are quite a few threads on the forum about diagnosing the faults, depending on what equipment you have to hand...and a particularly long and involved one from @rubber_jonnie about one of his Megas.

Hopefully some of the ideas in those topics will get you started & you can post your initial findings in a new topic so the many experts can help you diagnose & fix it.
There are also a few people on here who might be able to diagnose & fix the system for you if it's beyond your comfort level!

Good luck.

[rubber_jonnie]

Hi @Gotang and welcome to the forum.

I suspect we've already been chatting quite a bit on FB messenger. I can't stress enough the importance of working through things logically, and you really need to gather good solid diagnostic data, or you can spend a lot of time going round in circles.

It looks very like the problem my Mega 4 had, corrupted screen and not booting. I know you have a diag cart, and I can't tell you how useful this can be, so you really do need to find a way to hook it up to serial as when the screen is failing like that, having results via the serial output is invaluable.

FYI, this post here: https://www.exxosforum.co.uk/forum/viewt ... =40#p27737 shows the RAM bank layout and bit mappings which are incredibly helpful when it comes to working out what RAM chips to replace if it comes to that. My money is is on a bad data line if I'm honest, as we've already chatted about.

Welcome to the forum and keep us appraised of your troubleshooting progress.

[Gotang]

hi bud was not sure rubber_jonnie was your name on hear yes its me your pest lol
yea starting to think your on the money with the data line thing more testing to do today before the f1 starts lol
again you have been a massive help bud cant thank you enough
sent you a pm got a laptop to connect to the mega what software do i need on it ? ordered the cables to

gotang