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Re: mrbomberzilly's MegaST maintenance

Posted: 03 Oct 2022 12:27
by Badwolf
Steve wrote: 02 Oct 2022 18:12 Now the blitter patch is fully installed within the CPU socket
Image
That's some dead fancy soldering, Steve!

BW

Re: mrbomberzilly's MegaST maintenance

Posted: 03 Oct 2022 16:02
by frank.lukas
... you can also solder between the pins from the outside.

7474.jpg
cpusockel.jpg

Re: mrbomberzilly's MegaST maintenance

Posted: 03 Oct 2022 16:32
by Badwolf
frank.lukas wrote: 03 Oct 2022 16:02 ... you can also solder between the pins from the outside.
Wow, you two are far too neat. I would have just relocated the board and run fly-wires to the bottom!

BW

Re: mrbomberzilly's MegaST maintenance

Posted: 03 Oct 2022 18:55
by alexh
Nice work. Enjoyable read.

Out of curiosity, as an alternative to a Blitter Patch board, are newer ICs available anywhere? Best Electronics? B&C?

(I understand that the distinguishing mark is the date code rather than a revision number)

Re: mrbomberzilly's MegaST maintenance

Posted: 03 Oct 2022 19:04
by Steve
And now for the finals, PSU recap using Panasonic FR caps & Nichicon for the 400v cap.
The PSU before re-cap
PXL_20221003_163115849.jpg
The PSU after re-cap
PXL_20221003_174741768.jpg
Testing the 12v rail
PXL_20221003_175352033.jpg
Testing the 5v rail
PXL_20221003_175357776.jpg
A happy MegaST4 :)
PXL_20221003_175729648.jpg

Thanks for all the kind comments! Will be shipping this back to @mrbombermillzy soon. Might just burn him a new TOS version before it leaves.

Re: mrbomberzilly's MegaST maintenance

Posted: 03 Oct 2022 19:30
by exxos
:bravo: :coolpics:

Re: mrbomberzilly's MegaST maintenance

Posted: 03 Oct 2022 20:04
by alexh
Nice work.

So this work stems from this thread? "Mandatory Fixes"?

https://exxosforum.co.uk/forum/viewtopic.php?t=1585

Re: mrbomberzilly's MegaST maintenance

Posted: 03 Oct 2022 20:16
by stephen_usher
I see that you have the same multimeter as I have... One of the good ones from Maplin in the 90s.

Re: mrbomberzilly's MegaST maintenance

Posted: 03 Oct 2022 20:39
by Steve
alexh wrote: 03 Oct 2022 20:04 Nice work.

So this work stems from this thread? "Mandatory Fixes"?

https://exxosforum.co.uk/forum/viewtopic.php?t=1585
No not really. It's just a re-cap of everything. General tidy and service. Socket CPU for future upgrades etc. Bus resistors have been socketed so that @mrbombermillzy can change them without needing to solder, if he gets an accelerator later etc. Right now the system is functioning perfectly fine so the resistors are still original. But like I say, they can be swapped easily now if needed in the future.

This system is the test bed of his dual shifter board, so he just wanted it to be given some love and maintenance basically.

Re: mrbomberzilly's MegaST maintenance

Posted: 03 Oct 2022 22:09
by mrbombermillzy
This is some great work @Steve. I really appreciate the effort put in here. :D
stephen_usher wrote: 03 Oct 2022 20:16 I see that you have the same multimeter as I have... One of the good ones from Maplin in the 90s.
Funnily enough, although I have minimal electronics servicing/repair items, I still have this same multimeter as well! I remember picking it out in one of their old telephone book size catalogues, as it had a very good spec and was reasonably priced at the time. Wasn't there also a 'silver' version? I still have the original little operations manual (more like a leaflet) for it too.