JezC H4 Build - in slow time

Topic for users to share their building progress.
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JezC
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Re: JezC H4 Build - in slow time

Post by JezC »

PhilC wrote: Sun Aug 29, 2021 11:18 pm @JezC if you're struggling, I'm happy to take a look at some point?
@PhilC Appreciate the kind offer... I'll have a bit of a probe around to see if I can spot anything obvious (and try to hone my diagnostic skills in the process!).

If I don't make any progress then I will send it your way!

:2k2:

I think the most likely cause is that the keyboard slipped & pulled the connector off the pins on the mobo...so I had to straighten the pins.
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JezC
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Re: JezC H4 Build - in slow time

Post by JezC »

And we have progress!

Over 2 months since I broke it...I finally managed to finish the fault-finding & get it back to some level of a working state!

Turns out that one of the large SMT capacitors had failed short circuit (which has happened to @exxos on one of his boards IIRC), so I've finally managed to remove that & the machine now boots once more.

Sadly, when removing a couple of the ICs (one 6850 & the 2149F) the sockets have failed so they need replacing before I do much more...but we have a resurrected H4!

Next step will be to fit the floppy drive/Gotek and then try to see what is different between my H5 and this (currently working) H4...

I now need to be careful not to make a habit of this or @PhilC will be out for revenge! ;)
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JezC
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Re: JezC H4 Build - in slow time

Post by JezC »

One other "minor" irritation during the above is that the old LCD TV that I've been using for my H4/H5 investigations has decided to stop powering up... :headbang:

It now sits there with the power LED coming on briefly & then flicking off again, so I suspect a cap has succumbed to age.

Rather than get diverted by this new catastrophe, I just moved over to the Benq monitor I usually use with the original machines & fortunately that works enough to prove the H4 is alive.

I'd vaguely remembered some comments about the UBE video adaptor not working on the H4/H5 (no 12v on the monitor socket on the H4/H5???) so I snaffled the Exxos one out of one of my Megas & that worked well enough for this first test.
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exxos
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Re: JezC H4 Build - in slow time

Post by exxos »

JezC wrote: Mon Nov 08, 2021 9:29 pm I'd vaguely remembered some comments about the UBE video adaptor not working on the H4/H5 (no 12v on the monitor socket on the H4/H5???) so I snaffled the Exxos one out of one of my Megas & that worked well enough for this first test.
They have 12V on the socket. Mine still need power to the chip on the ST2VGA board. I don't remember any comments about the UBE not working unless anyone else does ?
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
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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: JezC H4 Build - in slow time

Post by JezC »

exxos wrote: Mon Nov 08, 2021 9:53 pm
JezC wrote: Mon Nov 08, 2021 9:29 pm I'd vaguely remembered some comments about the UBE video adaptor not working on the H4/H5 (no 12v on the monitor socket on the H4/H5???) so I snaffled the Exxos one out of one of my Megas & that worked well enough for this first test.
They have 12V on the socket. Mine still need power to the chip on the ST2VGA board. I don't remember any comments about the UBE not working unless anyone else does ?
Thought @terriblefire had a problem in his build thread? I'll check & add a link if I can find it...

EDIT: Link to TF build below with comment about UbeSwitch...
https://www.exxosforum.co.uk/forum/viewt ... =70#p39419
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JezC
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Re: JezC H4 Build - in slow time

Post by JezC »

Ok, so I've tried both the Exxos 'value' VGA adaptor & the Ubeswitch version on my H4 & both seem to work just fine!

So, next planned job is to fit my Trudie board & get that working...then I'm hoping to solder in the cartridge port & try out a couple of MIDI programs, then maybe even re-fit my TF536 to see what will work on the 030 with all that RAM....

Now where did I put that CF card...
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Re: JezC H4 Build - in slow time

Post by exxos »

JezC wrote: Mon Nov 22, 2021 10:22 pm Ok, so I've tried both the Exxos 'value' VGA adaptor & the Ubeswitch version on my H4 & both seem to work just fine!
:bravo:

H4 seems so long ago now :lol:
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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Re: JezC H4 Build - in slow time

Post by rubber_jonnie »

Wow, the first post in this thread was Feb 2020, it has really been a build in slow time!!

I have a couple of H4s to build, I'd better get on it so my finished one has company :)
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JezC
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Re: JezC H4 Build - in slow time

Post by JezC »

exxos wrote: Tue Nov 23, 2021 1:52 am H4 seems so long ago now :lol:
Yes, though I do like the greater ease of working on the through hole parts compared to surface mount stuff (that's not a dig at the H5, more the fine pitch TQFP & BGA packages we use at work).

Just glad to be back to having it working again...and this time I'll try not to do a @PhilC and break it again...or at least not until I've got that H5 floppy issue sorted!
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Re: JezC H4 Build - in slow time

Post by JezC »

rubber_jonnie wrote: Tue Nov 23, 2021 9:03 am Wow, the first post in this thread was Feb 2020, it has really been a build in slow time!!

I have a couple of H4s to build, I'd better get on it so my finished one has company :)
I did get it first working back in June 2020, so not quite that long really...it's just that I broke it earlier this year :oops: when trying to sort out some issues with the first H5 build (getting there, though the floppy issue is still not resolved yet). :roll:

I still have one H4 and an H5B1 to build at some point (plus the second TF536...waiting on PLD & DRAM courtesy of the global shortages).
Maybe it should be a friendly competition to see who builds up their next system first? Spoiler alert - it's almost certain to be you! :lol:
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