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Re: STE mods

Posted: 29 Dec 2020 10:45
by exxos
I suggest you check the mods page https://www.exxosforum.co.uk/forum/viewt ... =20#p41514 and also check you have isolated the clock pin on the CPU. Other than that, it was expected it wouldn't work as it was not intended to be fitted that way..

Re: STE mods

Posted: 29 Dec 2020 10:46
by HigashiJun
If my CPU was socketed, I would have fit the booster the traditional way.

But since I had to add a PLCC socket, I had to fit the booster using a less formal method.

You may have a look at IngoQ's thread:

https://www.exxosforum.co.uk/forum/viewt ... f=18&t=358

Cheers.

Re: STE mods

Posted: 29 Dec 2020 10:52
by HigashiJun
Thanks Exxos.

I have already changed the resistor on the booster to a 68R one (SMD).

I will check connections again and test other SIMMS.

As I wrote before, I will not blame you if the booster does not work. :D

Cheers.

Re: STE mods

Posted: 29 Dec 2020 11:04
by exxos
Have you tried in 8mhz mode ?

Re: STE mods

Posted: 29 Dec 2020 11:22
by HigashiJun
Yes, I have grounded the switch wire but nothing happens.

As said in my previous post, nothing works even with the booster removed and with the original CPU back in place.

I do not understand why the Ultrasatan gets powered but not the FDD, although it was working before.

I really suspect the SIMMs with the parity chip de-soldered.

Re: STE mods

Posted: 02 Jan 2021 03:39
by HigashiJun
I had some time today to check all connections again and everything is OK. There are no broken traces nor other glitches...

I was just wondering if the two spots IngoQ referred to in his thread were not inverted (sorry IngoQ, I reused you picture...):

CPU_CLK_Vias.jpg

Should not CLK8 be the lower spot and CPU_CLK the upper one ?

I might be wrong, but if you guys have some ideas, do not hesitate to share.

By the way, my cheap Chinese crap socket cracked while removing the CPU. I ordered some 3M brand ones and I will have to de-solder the old one and solder again a new one on the motherboard. Lesson: never use crap stuff for your projects, you will always have some issues sooner or later... :x

Cheers.

Re: STE mods

Posted: 02 Jan 2021 06:28
by HigashiJun
And of course, it never rains but it pours...

While de-soldering the broken socket, I also managed to break a solder pad:

Solderpad.JPG

It is not a problem to repair it (I made a lot before...), but it is just a waste of time.

But let us keep it positive, 2021 has just begun... :D

I will post some pictures when the pad gets repaired.

Re: STE mods

Posted: 02 Jan 2021 10:02
by HigashiJun
Ok, my little broken pad is now repaired:
Newpad.JPG
Epoxied.JPG

The last step is tinning, but the epoxy has to cure for 24 hours.

And here is what you need to perform the magic:
Tools.JPG

I prefer when the pad is only lifted, because the repair process is much easier and you keep your original pad.

I could have used the original pad here but the broken trace was too short, making it impossible to align all the pads evenly on the left side.

Now I will have to solder the new PLCC socket as soon as I receive it.

Cheers.

Re: STE mods

Posted: 02 Jan 2021 16:13
by Steve
Nice work on the pad! I hope you get it working :)

Re: STE mods

Posted: 02 Jan 2021 16:43
by rubber_jonnie
Pad repair looks nice, if anything will hold onto it it's epoxy.

Had to fit a similar socket on my Mac Classic, which still isn't running. It is a bit of a faff to get going because of the need for the analog board and CRT, but it does have composite out so I may try to get it to output to that and power it off my bench PSU whilst trying to fix it.

68K_Socket.jpg

We'll see.

Good luck with your repairs and the booster fit.