Neo Geo CD Front Loader - no video / audio

[awbacon]

I picked up Yagamikun’s boxed top loader. Beaut of a system…but she’s blind and mute.

No output on S Video or composite, no audio on the RCA lines. Tried two PVMs, Framemeister and an old 1080p LCF tv with composite in.

Checked the AV breakout board. No obvious signs of issues. The power plug did break connection if wiggled so I reflowed the solder on the power (even though I had power LED showing) as a first step. No improvement

Caps look nice (I mean they could be dry, but I doubt it) and the diodes read as good.

My next guess is a bad inductor / power not leaving the AV breakout board and getting to the motherboard itself and I will test that…as I’ve read some fixes on top loaders where that’s the issue…but obv that’s not a direct match to a top loader.

Anyone have this issue and repair it? Trying to find some leads before I just dismantle the entire unit down to the component boards and check ebeeyhing

I should say Yagamikun was a consummate awesome member and offered to take the unit back but it’s so damn pretty I’d rather not send it back Lolol

 

[awbacon]

update: all the power rails are good into the motherboard...which is really not helping me narrow down shit

 

[HeavyMachineGoob]

I've owned two NGCD front loaders and haven't had AV issues on either of them, can't think of anything to suggest at this time, sorry.

 

[awbacon]

I've owned two NGCD front loaders and haven't had AV issues on either of them, can't think of anything to suggest at this time, sorry.

neither can I...whomp

 

[Arcade Magician]

Any bulging caps on the auxiliary board?

 

[awbacon]

Any bulging caps on the auxiliary board?
View attachment 59609

Nope. Caps look good / test good

That's why its extra confusing so far....none of the obvious things. Power rails are good...caps are good

I will have to take the whole console out of the shell and rebuild it on my table so I can test further as its not very easy to dig into it without a full disassembly

I tried to blindly navigate the menu based on photos to see if I could hit the eject button via the OS but that isn't working either so something isn't "waking up"

 

[Tarma]

Shot in the dark - is the psu supplying the correct voltage? Are you using a stepdown or just plugging it straight into the mains?

Not sure how sensitive these things are to voltage differences. I've always used stepdown transformers to get 100v to all my Japanese hardware.

Anyway, hope you get the issue sorted.

 

[awbacon]

Shot in the dark - is the psu supplying the correct voltage? Are you using a stepdown or just plugging it straight into the mains?

Not sure how sensitive these things are to voltage differences. I've always used stepdown transformers to get 100v to all my Japanese hardware.

Anyway, hope you get the issue sorted.

Yes I checked voltage into the breakout pcb and from that pcb to the main motherboard and everything is in spec. So it doesn’t seem like a power ossue

I need to check all the caps on the motherboard next but that’s a metric ton of tear down I’ll save for a rainy October day.

My first thought was voltage though. Its “playing blind” as in no audio/image but SOMETHING is outputting because the screen changes to a slightly diff color of grey on a TV and it pulls a signal on my Framemeister (from blue screen to grey)

But it’s not reading controller inputs because I used a known good controller and tried to blind navigate the menu screen via an image to get they tray to eject…nothing.

Edit : I tried both mains and step down. Zero change in behavior.

What I hope it’s NOT is a chip issue on a custom

 

[Tarma]

Ugh... not heard of a chip issue with a Neo CD before, but that doesn't mean to say it's not possible.

If it is a chip issue my best advice would be to head to YHJ! find yourself a loose front loader, don't worry about cosmetics, get it shipped over and gut it for the mobo. Most front loaders listed as "junk" have either packed up lasers or the CD draw won't open anymore. You'd be damn unlucky to have two units with knackered mobos.

If that works you can then either keep the other unit for spares or flip it on eBay and sell it for "spares/repair" and let someone else deal with it.

 

[awbacon]

Ugh... not heard of a chip issue with a Neo CD before, but that doesn't mean to say it's not possible.

If it is a chip issue my best advice would be to head to YHJ! find yourself a loose front loader, don't worry about cosmetics, get it shipped over and gut it for the mobo. Most front loaders listed as "junk" have either packed up lasers or the CD draw won't open anymore. You'd be damn unlucky to have two units with knackered mobos.

If that works you can then either keep the other unit for spares or flip it on eBay and sell it for "spares/repair" and let someone else deal with it.

Yes that will be last resort but I thought about gut swapping it. But I am motivated to figure out what went wrong if for nothing else than to do it / leave a record for the next person who encounters the issue

 

[Tarma]

Yes that will be last resort but I thought about gut swapping it. But I am motivated to figure out what went wrong if for nothing else than to do it / leave a record for the next person who encounters the issue

Yes, would be interesting to hear what the cause of the issue is. Dry solder joint or bad trace? Let us know if you find out!

 

[awbacon]

Yes, would be interesting to hear what the cause of the issue is. Dry solder joint or bad trace? Let us know if you find out!

I’ll find it eventually. It may come down to checking logic though. Which I hate / am not great at. It worked at some point then was put away and came out not working (from who I got it from) so I’m leaning on something “went bad with time” and I just haven’t found it yet

 

[Tarma]

Any update? Curious to know if you fixed it or had to resort to cannibalising a loose "junker".

 

[yagamikun]

I still feel SO bad about this! lol - Glad we could work it out to a deal you were satisfied with. But yes, I'm interested to see what's wrong as it was working previously. It was my daily unit until I got a top loader to replace it because, as you said, it's just so pretty and in excellent condition with matching serials, etc. lol.

 

[awbacon]

Any update? Curious to know if you fixed it or had to resort to cannibalising a loose "junker".

no update yet. On my list of shit to get to

but that also involves; building and diagnosing a rare Konami Cobra board before I send it to a friend for reballing. Fixing a NWK-TR Thrill Drive board. Fixing an NWK-TR Racing Jam board and building a harness to test a Konami Midnight Run board

I have too many projects lol

edit: oh and multi modding a Konami Viper board lol

 

[awbacon]

I still feel SO bad about this! lol - Glad we could work it out to a deal you were satisfied with. But yes, I'm interested to see what's wrong as it was working previously. It was my daily unit until I got a top loader to replace it because, as you said, it's just so pretty and in excellent condition with matching serials, etc. lol.

No worries. Shit happens. You were cool about it and that's all I ask

 

[Neo Alec]

So I've got this system now, and it's actually powering on and working just fine with both of my AC adapters. It just doesn't work with the AC adapter it came with, and @awbacon also said it doesn't power on with his CDZ adapter (which works for his CDZ).

I measured the voltages of all of my AC adapters (the frontloader is the one it came with):

frontloader
5.6
9.39

toploader
5.54
9.48

CDZ
5.57
9.4

These are all a bit low for the 10v, but I kind of doubt the .01v difference is what's doing it. The 5.6v is a bit high, but it shouldn't be a problem for the regulator inside.

So I opened and I confirmed that even though the AC adapter it came with fits looser than the others, it is indeed making a good connection in the jack, and the voltage is measuring good off of the voltage regulators inside.

So I'm thinking the problem with this AC adapter is amps, not volts. Perhaps a recap of the AC adapter is in order.
Edit: The power supply is working with my toploader. I'm guessing with the frontloader being bigger and older it may require more power.

 

[Tarma]

Thanks for the update. I was curious as to what the issue was... and it just turned out to be just a duff ac adapter?

Funny thing is nos ac adapters still pop up regularly on YHJ!... it's the CDZ you have to watch out for. Those psu's are super rare.

 

[Neo Alec]

Oh yeah, one other thing: The bad power supply is working fine with my toploader.

Funny thing is nos ac adapters still pop up regularly on YHJ!... it's the CDZ you have to watch out for. Those psu's are super rare.

Yep, and the old difference is the shape of the plug on the end.

 

[wyo]

Most times when a NGCD or AES doesn't work right, it's PSU related. That's been my experience at least. Also, fuck me for not buying this again.

 

[awbacon]

Glad it was fixed.

I tried two power adapters, reflowed the power connector and checked all the caps on the break out board. That didn’t solve it so into my pile of projects it went.

But that pile of projects was too damn big so on to the next person it went. Glad to know I wasn’t crazy though and it was power related

Now it’ll have a good home. I was going to start with a full recap but again…probably wouldn’t have gotten to it till 2024

 

[Tarma]

Also, fuck me for not buying this again.

Ha, yeah you missed out on quite the bargin... but to be fair, no one knew it was definitely just a faulty psu.

 

[Neo Alec]

Ha, yeah you missed out on quite the bargin... but to be fair, no one knew it was definitely just a faulty psu.

Yeah, and like I said, since I tried the PSU on the toploader, there's a good chance it's not just the PSU. The system and the PSU are probably getting old and both could use a recap.

If someone without a spare PSU had bought it, we'd probably still be here trying to figure it out. Buying another PSU would have been a gamble without knowing for sure if that was the problem.

 

[Tarma]

Yeah, and like I said, since I tried the PSU on the toploader, there's a good chance it's not just the PSU. The system and the PSU are probably getting old and both could use a recap.

If someone without a spare PSU had bought it, we'd probably still be here trying to figure it out. Buying another PSU would have been a gamble without knowing for sure if that was the problem.

Out of interest are you using a stepdown with your set-up or just plugging the psu straight into the outlet?

 

[awbacon]

Out of interest are you using a stepdown with your set-up or just plugging the psu straight into the outlet?

When I tested it it was on wall voltage AND a step down, so the problem would not have appeared.

Interestingly the PSU tested good on my multimeter / the voltages into the rails were good as well. So my presumption was the problem was further down the line. I had proper voltage out of the break out board as well.

So while I’m glad he figured it out, it’s still a bit confusing as to how. My CDX power supply black screened the unit too