Booster V4sm problem

[zfrenchy]

the original on board is a F.

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Is it snowing now ?

[zfrenchy]

I cannot make it to fail this morning !!!! But still not having the ATARI logo and RAM test at boot.

You know you only get the logo with TOS206 ?

OK OK, I know you said before, but my TOS switch is a fail, I put a jumper, and now TOS 2.06 is working.

WAIIA !!! (what an idiot I am)

[exxos]

the original on board is a F.

Is it snowing now ?

Mystery...

OK OK, I know you said before, but my TOS switch is a fail, I put a jumper, and now TOS 2.06 is working.
WAIIA !!! (what an idiot I am)

Oops

I wonder if that's part of the 32mhz issue then ? Best to use jumpers and not tie into the booster speed control for diagnostics..

[zfrenchy]

I replaced the 74F257, will see.

But, before I re-solder the 32Mhz wire, should be this wire on pin 3, NOT 4 ?

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[exxos]

Pin4 is buffered output.. so its correct.

[HigashiJun]

Just remember an issue I had with the booster on one of my STE motherboards:

While the thin wire provided in the kit was OK for the 32MHz signal in two of my motherboards, one motherbaord had however issues with it.

When I swapped the thin wire for a normal Dupont one, the booster started working without any glitches.

[exxos]

Just remember an issue I had with the booster on one of my STE motherboards:

While the thin wire provided in the kit was OK for the 32MHz signal in two of my motherboards, one motherbaord had however issues with it.

When I swapped the thin wire for a normal Dupont one, the booster started working without any glitches.

Wasn't aware of that, at least what I remember..

The wire gives some small resistance, but looking at the scope images, even after the 68R there's hardly any difference.. So I don't really understand why a different wire would be any different..

A 68R in series with the wire on U405 might be worth trying..

[HigashiJun]

So I don't really understand why a different wire would be any different..

Me either... And only one motherboard was concerned.

[exxos]

Me either... And only one motherboard was concerned.

Next time I have mine connected I'll takes some measurements to see if can see any difference..

[exxos]

YELLOW = U405 end
BLUE = STE BOOSTER END

Thin black wire end to end.

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Thin black wire end to GAL pin1 (68R series)

IMG_4463.JPG (296.05 KiB) Viewed 1145 times

Wire end to end.

IMG_4465.JPG (323.82 KiB) Viewed 1145 times

wire end to GAL pin1 (68R series)

IMG_4466.JPG (310.66 KiB) Viewed 1145 times

So not much of a difference.. But I remember now other wires were causing the "1712 shifter bug"...