Neo geo Cd Black Screen

ladyxyuna

n00b
Joined
May 6, 2023
Posts
6
Hello Guys! I have one Neo geo cd that it has black screen. I searched here or YouTube about this case. I found that I should change the inductors, because it should have around 4,94v each side. However, one of my Neo geo is cda3-1 board and the inductor L2 shows 8.12v one side, another one 7.42v. Although I replaced two times this inductor, it shows the same voltage. Other inductors are ok.
My question is. Someone knows what it could be?
Thanks for supporting
 

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Neo Alec

Ned's Ninja Academy Dropout
20 Year Member
Joined
Dec 7, 2000
Posts
11,996
Is this a top loader?

I had that happen with a front loader. The power supply was going bad. Using another power supply fixed the issue. So I would check the power supply next.
 

ladyxyuna

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Joined
May 6, 2023
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Is this a top loader?

I had that happen with a front loader. The power supply was going bad. Using another power supply fixed the issue. So I would check the power supply next.
It is top loader. I have another power supply, but it is cda01. It doesn't fit my neo geo that it is cda03
 

prof

A Great Place to Store Your Dildo Collection
Joined
Jul 15, 2015
Posts
1,249
I recently replaced an inductor on my CD unit to fix what sounds like a similar problem; however, my board is a CDA4-1, and the placement of some of the components appear to be different than mine in your photo. On my board, I tested each inductor point and got 4.9v except for one point which read only 1.5. After replacing that part with a new inductor, my video came back, and the unit has been operating properly since. In fact, I posted a thread about the process recently here in the Tech Support forum.

Since I have a different board than yours, I can't verify that your inductor readings of 8.12 and 7.42 are where they should be or not, but it is worth noting that every inductor on my board read 4.9v. And those figures are a big difference. Are you sure that you aligned the inductor properly when soldering it in? Meaning, were the colored rings in the same alignment in your replacement as the original was? Perhaps you placed the new one in backwards. It would be an easy mistake to make.

Again, since your board is a different revision than mine, I can't confirm, but if I were you, I would seek out a photo of a stock board to make sure the stripes on the stock inductor match up with the one you've replaced it with.
 

ladyxyuna

n00b
Joined
May 6, 2023
Posts
6
I recently replaced an inductor on my CD unit to fix what sounds like a similar problem; however, my board is a CDA4-1, and the placement of some of the components appear to be different than mine in your photo. On my board, I tested each inductor point and got 4.9v except for one point which read only 1.5. After replacing that part with a new inductor, my video came back, and the unit has been operating properly since. In fact, I posted a thread about the process recently here in the Tech Support forum.

Since I have a different board than yours, I can't verify that your inductor readings of 8.12 and 7.42 are where they should be or not, but it is worth noting that every inductor on my board read 4.9v. And those figures are a big difference. Are you sure that you aligned the inductor properly when soldering it in? Meaning, were the colored rings in the same alignment in your replacement as the original was? Perhaps you placed the new one in backwards. It would be an easy mistake to make.

Again, since your board is a different revision than mine, I can't confirm, but if I were you, I would seek out a photo of a stock board to make sure the stripes on the stock inductor match up with the one you've replaced it with.
Dear friend, I read your entire article, in addition to watching videos on youtube. Your tutorial helped me to solve the problem of my other neo geo cd with the same CDA4-1 card as yours. However, mine is CDA3-1, and there is an IC2: +8V Regulator that sends current to a 200 ma diode. Through a jumper parallel to the diode, this inductor receives 8V on both sides. I checked all resistors in the region, and they are normal. The 8V arrives from IC2 and there is nothing to interfere with it. So I assume that inductor is 8v. I will try to change the RGB Encoder: CXA1645P and the two OPAMP1: uPC844C.
 

Xian Xi

JammaNationX,
15 Year Member
Joined
Dec 1, 2005
Posts
27,750
Put a music CD in and see if it plays blind. Also check the voltage on the CXA chip not the inductor.
 

ladyxyuna

n00b
Joined
May 6, 2023
Posts
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Put a music CD in and see if it plays blind. Also check the voltage on the CXA chip not the inductor.
I have two Neo GEo Cds, so I have one it works normally. So I replaced CXA chip from the neo geo doesnt work, and it worked fine my another neo geo. Could it be the motherboard?
 
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