*** M E M O R U M ***

I think that´s very useful. I tried a few searches and it came back with the right results. Thanks a lot!

Maybe the search button should be visible on the left hand side of each page?

Yes, bolt and nut have been removed. All that moves is the plastic back panel, until it stops at the heat sink. The board itself seems to be cemented in - does not move a bit.

I removed the memory board, but still did not manage to remove the main board. :( The memory board hardly moved in its slots, but the main board simply does not move a nm! I double-checked the plastic backplate again and found that it cannot be pushed to either side, since the metal heat exchanger o...

It´s getting embarrassing again. How the hell does the board get removed? I took off the keyboard, the video board and the screw on the back, but both the main board and the memory board do not move a mm! I also cannot remove the rear plastic bar (on the connectors). This one moves a bit to the left...

Thanks for the suggestions. Unfortunately I don´t have access to a scope and my HP DVM is way too old and slow.

I think I should try the regulator replacement; just about to order the parts. I´ll report back if there´s any improvement.

Beside from a few specials like the Orics, a Didaktik etc., it´s mainly Spectrums, a few QLs and three Sam Coupes.
The whole lot can be seen on --> http://schombi.de/my-retro-collection.html

@thewiz: Spectrum looking for a good home? Drop me a message.

The service manual also mentions that some video signal problems could be caused by a faulty 7805/7812.

Replacements should be UA7805/UA7812. These are hard to get, so I wonder if the standard 7805 used in the Spectrum would also work? For the 7812, would ST L7812CV 12V/1.5A work?

I had a quick look at the launcher on the week-end. Looks good to me. Thanks for the work, Bill!

You guys were right! It was F1 (along with "o"), that was stuck. After using some IPA and "hammering" each key, I managed to boot up the MTX and get all keys working. That´s good progress! :) I did not dare swapping the video boards, but I removed the one from this unit, had a cl...

Finally I was able to carry out some more troubleshooting. First of all I re-checked all connections and re-seated all socketed chips. I also tightened up the connection to the monitor output. Looks like Bill B was right. There is something weird going on with the keyboard. With the keyboard removed...