deadl0ck

It lives !! Q7 and Q8 replaced and it lives ! The screen looked VERY bad at first: I checked the screen connectors on the flex cable and there were 2 that looked a bit bad, so a little bit of conductive paint and I now I have this: Thank you SO MUCH @Stephen Moss and @-^CrossBow^- !! Another Lynx comes back to life thanks to you both

So no joy there with the cartridge - I can wiggle it around and sometimes I can see the complete Insert Game message but that's it - I then checked it with C41 to 5V and the game starts - so it's something else other than a bad connection - I guess I should replace the 2 transistors as a first step anyhow.

So looks like I'll need to do the transistors at Q7 and Q8

So replaced the Zener and there are some signs of life... the screen is darker and some flashing image on it Here's the zener replacement (sorry about my terrible soldering skills): And here's a quick video of the screen now: https://photos.app.goo.gl/yoPgGZaXAHai1bij8

I replaced the mosfet but not the Surface mount ones - they look tricky !! (Although I did get them in my power rebuild kit) I did the mosfet separately as it came with the cap replacement kit which I also did. I'll start with the zener and see how it goes, but like I said I've never done a surface mount one before (My hands seems abnormally shaky whenever I try and do delicate work like that !) I'll keep you posted and thanks again for the help and encouragement !

But If I leave it off and use the 11 and 14 on U6 as @Stephen Moss suggested I can turn it on - if I can do that can I leave the flex disconnected as there are a lot of worn/broken traces on it ? And to double-check - It's D13 that I need to replace (as I have a zener replacement I got in a small power kit) ?

It's D13 right ? (The Zener I need to replace) Also - when I just switch back to the batteries (as opposed to 5V on that cap) I should still be able to test without the Flex connector connected ? Thanks again !

I got a 5.01V Supply and did as you said @-^CrossBow^- and the game started right away !! So it seems to be a power issue

Will do - thanks !!

Actually @-^CrossBow^-, I have a USB Power bank and an old iphone USB charger that I just striped the wire from and I can get a steady 5.43V out of that - would that be OK ?

Brilliant - thanks for all the help !!

Thanks @-^CrossBow^- And you reckon I don't need to have the flex circuit attached at all ?

Thanks so much for the detailed reply @Stephen Moss I have a DMM so it's time to start tracing stuff - it's a right pain trying to keep the batteries in the holder when it's taken apart (I don't have a power adapter) - time for some sticky tape I think..... Thanks again - I really appreciate it - we're back in total lockdown here too (Ireland) - stay safe !

HI - I eventually got back to looking at my Lynx II today. I have the flex cable totally disconnected as there are so many bad traces on it I can power it on by touching pins 14 & 11 of U6 with a piece of wire, as you suggested @Stephen Moss but all I get is a lit up screen with no game starting. Could the wire from battery -ive to the headphone jack +ive that I did at the start have killed something ? Where can I go from here ? Thanks !

Thanks @Stephen Moss ! I was looking for a notch and couldn't find one - just as well I asked !! You the man !!