Chassis MS-2930
CRT: MS-2931-S (made 1999) / Toshiba A68LBT696X
There is a strange cyan smear or glow around some graphics. Strangely the test grid isn't that bad (beside the usual corners).
cyan glow:
http://imgur.com/EEIOepk
test grid:
http://imgur.com/lPcWHQL
Anyone has an idea?
Is this a convergence problem?
Edit: 31khz seems to worsen the effect.
Blast City MS-2930 cyan smear/glow problem
- pulstarx
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- grantspain
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Re: Blast City MS-2930 cyan smear/glow problem
has the chassis just suddenly displayed this issue?
- pulstarx
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Re: Blast City MS-2930 cyan smear/glow problem
Unfortunately no idea, I bought it like that.
- grantspain
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Re: Blast City MS-2930 cyan smear/glow problem
try a different vga cable first, then consider caps
- pulstarx
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Re: Blast City MS-2930 cyan smear/glow problem
Cables didn't make a difference:
http://imgur.com/vTIJ1lC
I reduced the symptom by reducing R/B-gain. But it only reduces the symptom and does not solve the problem. I could see it live reducing in the NAOMI color bar test.
Now I have the problem that the picture is too dull because the gains are down. (yes DIPs are okay).
Brightness/contrast and screen on the flyback don't help.
Any idea if some specific caps are the problem?
I suspect the ones near the RGBS cable towards the neck-board.
But I can't find any schematic/manual for the ms2930...
Does the neckboard look okay?
http://imgur.com/9Hdxmv6
http://imgur.com/vTIJ1lC
I reduced the symptom by reducing R/B-gain. But it only reduces the symptom and does not solve the problem. I could see it live reducing in the NAOMI color bar test.
Now I have the problem that the picture is too dull because the gains are down. (yes DIPs are okay).
Brightness/contrast and screen on the flyback don't help.
Any idea if some specific caps are the problem?
I suspect the ones near the RGBS cable towards the neck-board.
But I can't find any schematic/manual for the ms2930...
Does the neckboard look okay?
http://imgur.com/9Hdxmv6
- grantspain
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- Location: down south
Re: Blast City MS-2930 cyan smear/glow problem
blue is overdriving in the colour graduation screen
all the electrolytics in the power supply section and the 10uf 250v on the neck card
all the electrolytics in the power supply section and the 10uf 250v on the neck card
- pulstarx
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Re: Blast City MS-2930 cyan smear/glow problem
The general power supply in the top left corner?
I would have thought that the bottom right is the culprit as the RGB video signals go through there.
C201,C202,C203 + C211,C212,C223
- LegoYoda
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Re: Blast City MS-2930 cyan smear/glow problem
I literally just noticed the exact same problem on my Blasts 2930. Assuming I check out the caps and find a bad one (visually) is it worth doing all the caps at the same time? or just some to fix the issue?
Alec
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Owning a Blast City: Fixing and Repairing -http://retrogamingstuff.wordpress.com/
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Owning a Blast City: Fixing and Repairing -http://retrogamingstuff.wordpress.com/
- nem
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Re: Blast City MS-2930 cyan smear/glow problem
It's very unlikely you will find a bloated Nichicon cap. Unless you have an ESR meter, there's no way find bad caps. And even if you have one, if you're handy with a soldering iron, it's actually quicker to just outright change them.