C128D troubleshooting help needed - diagonal stripes on 40col

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Stealth
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C128D troubleshooting help needed - diagonal stripes on 40col

Post by Stealth » Thu May 18, 2017 7:33 pm

So I got my C128D package today, with the main unit, keyboard, three utility disks, 1351 mouse, A/V cable and 1802 monitor.

I assembled the whole thing, powered it up in 40col mode (no 80col screen) and it worked well for about ten minutes or so. I messed around 128 mode, went into 64 mode, went into CP/M mode using the provided floppy, returned to 128 mode. Then I powered everything off, plugged the mouse into the closer port, powered it on... and got greeted with this.

http://i.imgur.com/tLuyhMA.jpg

The chroma is gone and the entire image looks... out of sync.

Did I just brick it? Is it a dead IC like an 8701? It worked for a good ten minutes, please tell me there's something I can do besides despair. :(



Stealth
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Re: C128D troubleshooting help needed - diagonal stripes on 40col

Post by Stealth » Fri May 19, 2017 6:39 pm

Standing down red alert... hooked the 128D to a regular TV using just the luma cable (no combined chroma input on the TV) and it works yet again. Looks like the monitor is in need of a repair. Might also try wiring it up to a SCART or an S-Video connector with a chroma resistor.

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motrucker
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Re: C128D troubleshooting help needed - diagonal stripes on 40col

Post by motrucker » Sat May 20, 2017 5:22 am

The 1802 doesn't seem to hold up as well other Commodore monitors. You should look into getting a monitor that will display 80 columns, so you can really use the 128.
I use an Amiga 1080 with excellent results for both 40 and 80 columns. I also use a 2002 at times, but the 1080 has a better display.
C-64, C-128, and Amiga A2000 user

Stealth
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Re: C128D troubleshooting help needed - diagonal stripes on 40col

Post by Stealth » Sun May 21, 2017 10:49 pm

Thanks for the suggestion. I've also got an Orion CCM-1280 (friend gifted it to me) which does have both Y/C and RGBI-TTL mode and it would work for both 40col and 80col. However, that one has a different issue - after its first fifteen minutes, it started fading out very soon after powerup, so that might need a repair as well.

An additional issue is, it has a (to me) very unusual RGBI-in connector. It's an EIAJ 8-pin VTR connector, the cables are expensive, the plugs themselves are impossible to find, so I can't even wire up my own DE9-to-VTR adapter (which is a breeze because the only difference is two GNDs on the C128 side vs. one on the monitor side).

My ultimate solution will probably be H2Obsession's RGBI-to-RGBA converter and a Gonbes GBS8200 so I can hook it up to my standard LCD monitor.

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