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Re: Looks like I'll be getting a Mega ST4 soon
Posted: 12 Dec 2019 15:23
by exxos
PaulJ wrote: 12 Dec 2019 14:44
Never hurts to have some extra pull-ups available in various locations on the H4. :D
:lolbig: :merryxmas:
Re: Looks like I'll be getting a Mega ST4 soon
Posted: 12 Dec 2019 15:52
by PaulJ
exxos wrote: 12 Dec 2019 15:23
PaulJ wrote: 12 Dec 2019 14:44
Never hurts to have some extra pull-ups available in various locations on the H4. :D
:lolbig: :merryxmas:
I really didn't put it out there as a challenge. :stars:
Re: Looks like I'll be getting a Mega ST4 soon
Posted: 12 Dec 2019 16:53
by rubber_jonnie
PaulJ wrote: 12 Dec 2019 14:44
Don't cut it off RJ, bend it up and if you ever need another pullup you can wire wrap to the pin that's bent up along the body. Never hurts to have some extra pull-ups available in various locations on the H4. :D
Good idea!
:dizzy:
Re: Looks like I'll be getting a Mega ST4 soon
Posted: 12 Dec 2019 16:54
by rubber_jonnie
PaulJ wrote: 12 Dec 2019 15:52
exxos wrote: 12 Dec 2019 15:23
:lolbig: :merryxmas:
I really didn't put it out there as a challenge. :stars:
Oooh, I like a challenge!
Re: Looks like I'll be getting a Mega ST4 soon
Posted: 14 Dec 2019 14:45
by rubber_jonnie
I decided that today was the day for pulling out the resistor packs from the Mega 4 in preparation for the arrival of the 9 pin 2.2ks. Interestingly I found this resistor pack was cracked in the middle.

- IMG_20191214_143829.jpg (175.31 KiB) Viewed 3544 times
I know I didn't break it during removal but it could be a clue as to why things have been erratic if only three of the resistors were actually doing anything.
I'll post again once I have the ones installed.
The other thing is that some of the vias are already in a terrible state even before I get started. Nothing that a bodge wire can't fix though.
Re: Looks like I'll be getting a Mega ST4 soon
Posted: 14 Dec 2019 14:49
by PhilC
Funny what you can find when fixing old Megas, well done finding that SIL, woulda been a pain to find otherwise.
Re: Looks like I'll be getting a Mega ST4 soon
Posted: 14 Dec 2019 14:54
by exxos
Wow a cracked sil wouldn't help things that's for sure.
Re: Looks like I'll be getting a Mega ST4 soon
Posted: 14 Dec 2019 15:37
by rubber_jonnie
It potentially answers the questions of why it would sometimes just die when I next powered it off and on. I'd manhandle the board, then it would work again. Possibly the cracked SIL making and breaking a connection. Finally when I manhandled the board a lot during the CPU removal, I reckon it finally finished the SIL off.
We'll see what happens when I fit the new ones.
@exxos it had a mix of 4.7k and 10k, I take it 2.2k all round is fine?
Re: Looks like I'll be getting a Mega ST4 soon
Posted: 14 Dec 2019 15:57
by exxos
@rubber_jonnie yeah I use 2.2k all around.
Re: Looks like I'll be getting a Mega ST4 soon
Posted: 14 Dec 2019 16:03
by rubber_jonnie
@exxos Cool thanks.