H5C1- firST STeps

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JezC
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Re: H5C1- firST STeps

Post by JezC »

Well, I just tried re-soldering some of the connections on the GLUE socket (4 or 5 looked a bit iffy)...but sadly that's not fixed it.

I'll re-test with the diag cart tomorrow & see if the errors reported are the same or not...if it's the same then I'd better dig out the schematics & see which connections might be faulty & causing the bus fault (especially with which address lines are required for the floppy accesses).
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JezC
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Re: H5C1- firST STeps

Post by JezC »

Yet more steps backwards on this...though the H5 is no better off, I've managed to damage the H4 somehow (possibly when testing the other keyboard, floppy drive/cable & PSU) so that won't power up now - no power LED on the keyboard, so I've probably managed to short something.

Even with all the other parts re-instated the H4 won't boot (but I've tried everything bar the floppy cable on the H5 & that is the same with all of them, so it appears to be the H4 board itself :( )...and with just the working PSU it still doesn't seem to boot.

I'll have to bell out the power & ground planes to see if I can locate the issue...ho hum.

Hope to get chance to look further into this over the Bank Holiday weekend...
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JezC
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Re: H5C1- firST STeps

Post by JezC »

Dug out my multi-meter & the H4 is showing ~0.7 ohms between GND & 5V (no keyboard, PSU or floppy connected, so just the H4 board and ICs fitted).

The H5 by comparison reads ~164 ohms, so that would explain the PSU not powering up into a near dead-short!

Since this H4 board was previously working, I'm hoping it's either something bridging across the supplies on the outer layers or a dead IC or similar.

Now all I need is the time to start investigating...
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exxos
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Re: H5C1- firST STeps

Post by exxos »

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JezC
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Re: H5C1- firST STeps

Post by JezC »

Yes, way beyond what my Fluke can do...I'll check if they have something similar at work (but I'm not sure if they do).

I've pulled all the socketed chips,SIMM module etc. & the short is still there :(

Probably time to start looking at the schematics to see where there might be a short.

EDIT: I'll start adding these H4 diagnostic steps to the old H4 build topic rather than confuse this H5 one...
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JezC
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Re: H5C1- firST STeps

Post by JezC »

Inspired in part by @exxos having some of the RasPi Pico-based hard drives in stock again, I'm going to try and connect up the logic analyser to the H5 & see if that shows something re the bombs on accessing the floppy...

Can any kind soul point me to the schematics for the H5C1 - I know I've seen them at some point in the past (or though I had)...but as usual when I actually want to use them they are hiding somewhere...
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Re: H5C1- firST STeps

Post by exxos »

Don't think I have uploaded the C1 yet, but basically same as rev A anyway viewtopic.php?f=89&t=3457

EDIT:

viewtopic.php?f=89&t=6524
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
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JezC
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Re: H5C1- firST STeps

Post by JezC »

exxos wrote: Thu Sep 14, 2023 5:48 pm Don't think I have uploaded the C1 yet, but basically same as rev A anyway viewtopic.php?f=89&t=3457

EDIT:

viewtopic.php?f=89&t=6524
Thanks @exxos - now that is one less excuse I can use for not getting the H5C1 working.... :lol: :roll:
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exxos
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Re: H5C1- firST STeps

Post by exxos »

JezC wrote: Thu Sep 14, 2023 9:06 pm Thanks @exxos - now that is one less excuse I can use for not getting the H5C1 working.... :lol: :roll:
Yes we need to know what the problem is! :chairsmack:

Looking back you seem to get bus errors from the diagnostic cartridge which is pretty bizarre as I will be more a CPU type fault.

Did you run RAM test from the cart and leave it running for a hour ?

Also if you can run floppy check on the diagnostic cartridge, have you looked to see the physical drive heads are moving and the disc is actually rotating etc ?
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
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exxos
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Re: H5C1- firST STeps

Post by exxos »

Looking back you posted this..

But SIDE 8 ?!
JezC wrote: Sat Aug 21, 2021 11:08 am Floppy test failed, see below
Disk A: DS
Formatting Side 8 Track 00
EB Bus Error Access Address: 4E4E58 Program Counter: 3B001F
EA Address Error Access Address: 3B001F Program Counter: FA0E88
EA Address Error Access Address: FD3FFB Program Counter: FABE8A
EA Address Error Access Address: 00386D Program Counter: FAGESC
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
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