my GCp (unnamed for now)

[dark_samus]

hey all just starting a worklog for my GCp

gonna do an OMGWTF cut on my board soon but I've run into a problem when testing suddenly

I lost video very randomly I desoldered all of the capacitors (the big ones) lost video and audio (expected) got video back with the composite on the chip but the signal was weird, after rereading Ashen's guide I saw the one of the caps needed to be resoldered in and that it would take care of the issue however upon soldering the cap in I lost video again, took another look at it and can't figure out why, I checked the direction of the cap and looked at the chip and my wires all looked well, also did some testing with my multimeter and all checks out with my portion of the wiring so why no video D:

 

[dark_samus]

HA! got most of my video problems worked out, seems it was 2 AM and I plugged in the white audio wire instead of the yellow composite wire anyways upon replacing the capacitors on the board I still get no video so I'm assuming that the heat from all of the soldering killed them.... on the tops of the 2 capacitors of the type that go into the vid circuit both had "220 6v" printed on them I thought 'hmm 220uf 6V?' so I looked on an old board I had laying there and found a 220uf capacitor at 16v (voltage just needs to be at or higher than the the original value 16>6) so I put this in the circuit and tried it, booted to a black screen, upon taking a wire and bridging it to both sides of the capacitor I got a video signal but as before it was weird (lots of interference) now my TV just says "no signal from AV device" seems that this capacitor was blown so it probly was a higher uf since voltage was higher than the gamecube even provides especially on a video circuit anyways I was thinking my AV chip was fried good to know it isn't

 

[Rohan Loomis]

i have 3 untrimmed gamecube boards that could be use for parts do you want them?

 

[dark_samus]

i have 3 untrimmed gamecube boards that could be use for parts do you want them?

PM me the price

 

[Rohan Loomis]

PM'ed

 

[dark_samus]

does anyone know the value of the capacitor in the video circuit?

 

[Blargaman91]

What capacitor would that be? I only know of 220 uf and 10 if caps in that area. But, I have removed all the caps at one point and retained video and audio. Your problem sounds like a damaged AV chip. My most recent motherboard lost audio very randomly, my guess being because I did not have a 2.4k resistor on pin 15 and booting it up without it killed it. That resistor may be the source of other problems. You should make sure you have it there (or you may get no video).

 

[dark_samus]

What capacitor would that be? I only know of 220 uf and 10 if caps in that area. But, I have removed all the caps at one point and retained video and audio. Your problem sounds like a damaged AV chip. My most recent motherboard lost audio very randomly, my guess being because I did not have a 2.4k resistor on pin 15 and booting it up without it killed it. That resistor may be the source of other problems. You should make sure you have it there (or you may get no video).

there is only one capacitor in the vid circuit but it says 220 but it is in fact NOT 220 uf I already tried one anyways AV chip is fine as with no cap I get a video signal but there is lots of noise on it and the video is fuzzy the cap is a filter cap not neccessary but you get crap video if it's not there

 

[dark_samus]

so for all of you following this worklog this is gonna be a PSP Gamecube and I've thought of a name

introducing the swiss cube fusion this ofc is refering to emu_kidid's swiss and the swiss on flash for wiikey fusions

EDIT: after reading a page on capacitor markings I think that the capacitor is 22pf capacitor.... that doesn't seem right... will do a bit more studying up on the subject

 

[kill00man]

It is 220 uF. Did you put a 2.4k resistor on the AV chip ? This one is critical.
The 220uF cap must be wired up in line.
From where are you getting your video signal when testing the cap filter ? Try it directly from the chip.
If PAL board, did you wire the mobo to your screen with the original cable (there is a cap and a resistor in it, which are important) ?
Are you already using zenloc reg ? If so, then you can try to shield it.
Here are several ideas to search. Anyway if you are getting vid from the AV chip (even weird) it is just some minor problem.

Hem and check the capacitor polarity.....

 

[dark_samus]

hmm.... so it is 220uf for sure? how do you know this? you can't trust the markings on the top btw anyways yes i DID check the polarity of the capacitor I haven't done any board cutting yet and haven't removed any other components other than the big capacitors on the board

 

[kill00man]

Actually I have ordered hundreds of capacitor from small tantalum to a huge 450V 22mF aluminium (big like a champagne magnum ) and NEVER encountered a wrong mark. Furthermore according to its size it is totally something around that value, which also sounds realistic for filtering purpose. Anyway filtering cap value are not critical (but 22pF is totally unrealistic as it would be a CMS cap in such case).

We will need a picture to see exactly which cap you removed

 

[dark_samus]

what I meant was on official things like game consoles computers etc. they use a different marking system on capacitors, resistors, and even some chips meaning the markings on the capacitors aren't reliable

 

[Blargaman91]

It's interence, and interference may be very bad or not bad depending on the little things. I would go for the regulators, no matter what you're using. Even the official regulator buzzes in a way that you can hear it, and it puts so much interference in the audio lines as to block everything.

Edit: That sounded kind of harsh. Sorry... about that.

 

[dark_samus]

It's interence, and interference may be very bad or not bad depending on the little things. I would go for the regulators, no matter what you're using. Even the official regulator buzzes in a way that you can hear it, and it puts so much interference in the audio lines as to block everything.

Edit: That sounded kind of harsh. Sorry... about that.

??????????????? what do the regulators have anything to do with this???? I'm saying when the cap was removed and the line was bridged straight thru there was all of the sudden a TON of interference on the video line in ashens guide he says the cap I removed was a video filtering cap and that if it wasn't there then the video quality would reduce dramatically

 

[kill00man]

Your issue is strange. I didn't wired up the cap on my mobo (after serious trimming) and the video is OK. Not perfect but totally playable for testing purposes. Is the quality that bad without the cap ?

I cannot believe that you killed the capacitor. Anyway you can buy a bunch of capacitors with many different values and test it out. I can't see another solution.

Did you put a common ground with the screen ? Please put a picture of which cap you removed/wired back and your wiring. We cannot help you more without it.

You can also try to put everything stock and check if it works.

 

[dark_samus]

this is the capacitor I removed that caused vid issues and my screen has these color changing bar things that go down they frankly annoy the Heck outta me (basically they darken the color of whatever object they are over)

that is the cap I removed also notice that several of the caps say 220 when they are clearly different