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Progress blog on CosmicPuppets STFM servicing

Posted: 13 Aug 2020 21:58
by Steve
Hey guys,

Just a progress blog that I'll update as I go:

Motherboard: C070523-001

Problems:
* Corruption on DMA transfers, Ultrasatan
* Video output issues with sync/banding

Required services:
1. New Exxos PSU
2. STFM Video capacitor replacements (exxos kit)
3. Remove old motherboard ram
4. Complete motherboard re-cap
5. DMA and floppy resistor pull-up fixes

Re: Progress blog on CosmicPuppets STFM servicing

Posted: 13 Aug 2020 21:59
by Steve
Just finished soldering in Exxos new PSU
new_psu.jpg
PSU in the machine
new_psu2.jpg
Test the machine boots with the new PSU
test_new_psu.jpg
Time to recap the video circuitry
video_old.jpg
All caps replaced and resistor added for sync
video_new.jpg

Re: Progress blog on CosmicPuppets STFM servicing

Posted: 13 Aug 2020 22:00
by Cosmic Puppet
:bravo:

Re: Progress blog on CosmicPuppets STFM servicing

Posted: 13 Aug 2020 22:03
by exxos
:bravo: Kill the rubbish marpet while your in there ;)

Re: Progress blog on CosmicPuppets STFM servicing

Posted: 13 Aug 2020 23:15
by rubber_jonnie
@Steve Nice work sir.

Re: Progress blog on CosmicPuppets STFM servicing

Posted: 14 Aug 2020 12:27
by Steve
Bye bye DRAM :)
IMG_20200814_121821.jpg
IMG_20200814_121802.jpg

Re: Progress blog on CosmicPuppets STFM servicing

Posted: 14 Aug 2020 13:42
by Cosmic Puppet
That's awesome!

Re: Progress blog on CosmicPuppets STFM servicing

Posted: 14 Aug 2020 15:45
by Steve
Remove the cap inside the modulator he says... Steve says no problems...

Holy mother of lord
IMG_20200814_131610.jpg
IMG_20200814_131646.jpg
Okay, job done lol
IMG_20200814_133035.jpg

Motherboard fully re-capped with Vishay, Panasonic and Nichicon caps.
IMG_20200814_154122.jpg

Re: Progress blog on CosmicPuppets STFM servicing

Posted: 14 Aug 2020 16:37
by PhilC
Looks like a nice job there @Steve

Re: Progress blog on CosmicPuppets STFM servicing

Posted: 14 Aug 2020 20:28
by Steve
Floppy drive resistor fix applied:
IMG_20200814_201402.jpg
Test floppy and system by loading frontier:
IMG_20200814_202613.jpg