Egyptian Enterprise 64 number 2

[rubber_jonnie]

OK, so the L2 mod simply provides a stable 14Mhz clock to Nick as it would seem the circuit that generates it gets unstable over the years.

Could I simply use one of the clock outputs on one of my clock boards to replace this?

More thinking required

[alexh]

I haven't been able to get a login on that forum so I can't see the pictures or download the schematics/diagrams in the thread I referenced for "The L2" fix.

[rubber_jonnie]

I haven't been able to get a login on that forum so I can't see the pictures or download the schematics/diagrams in the thread I referenced for "The L2" fix.

So here's the thing, I've been able to get on and frankly there isn't much to see.

Essentially the OP stated that whilst adjusting L2 on their machine the core broke and a replacement adjustable inductor couldn't be found.

Basically he removed this part of the circuit entirely from his machine as it wasn't working:

Screenshot 2026-10-22 at 12.04.30.png (426 KiB) Viewed 25 times

And replaced it with an oscillator that generates the 14Mhz clock that goes to Nick. I could do that with my clock replacement board, however I may consider seeing if L2 on this machine can be adjusted with the correct tool and that may be enough to change the shimmer.

[PhilC]

If it ain't broke, don't fix it, messing with that may cause the whole thing to misfunction.

[rubber_jonnie]

So case repairs done this morning

I started off by melting some staples across the cracks to help stabilise:

PXL_20261022_100939881.jpg (242.62 KiB) Viewed 19 times

Then I added GRP strips and UV hardening resin to add strength:

PXL_20261022_104503626.jpg (271.56 KiB) Viewed 19 times

I didn't add staples to the other machine since the case was just cracked, however since the case for this one was actually in 2 parts I felt the staples would give a bit more strength to the repair. They were just melted in with the soldering iron.

The case looks good now

PXL_20261022_104906864.jpg (317.32 KiB) Viewed 19 times

Yes, there are visible cracks on the outside, but unless I was filling them, sanding and painting the whole case they will always be there. For me thats the patina of age and I'm good with it.

My replacement keyboard membrane is in the post, so I need to do a few things with the mainboard, like look at the L2 thing and try out RGB 2 HDMI before I get round to reassembling.

Next up though the CPU is getting socketed so I can figure out wether or not the RAM IC is bad or the CPU.

[stephen_usher]

That 14MHz clock circuit is very voltage sensitive. Undervolt it on the +12V and becomes very unstable.

[PhilC]

Nice idea with the staples, been meaning to try something similar for a while bow

[rubber_jonnie]

If it ain't broke, don't fix it, messing with that may cause the whole thing to misfunction.

Yeah, starting to get bad vibes about messing with it TBH, it's been through so much and just works.

[rubber_jonnie]

That 14MHz clock circuit is very voltage sensitive. Undervolt it on the +12V and becomes very unstable.

Noted thanks.

[rubber_jonnie]

Nice idea with the staples, been meaning to try something similar for a while bow

For a while there were these kits that had wiggly metal 'staples' for fixing car plastics such as bumpers etc.

Seemed like a repeatable thing with staples on a smaller scale and it worked very well.