CDROM2 wont work in the IFU

[atman]

I have the standard "briefcase"-IFU setup.

I just had a PC Engine and the IFU to play with and I decided to buy a CDROM2 to the rig.
It was confirmed to work, and i is working IF i use it seperatly as a CD-player. Works really good.

But when I gonna use it in the IFU its dead. I suspect there is no power to the CD from the CDROM-EXT port.
Is there anyone that have a schematics for the CDROM-EXT-port?

And when I power on the IFU by slinging the front switch the CDROM should have power?, like should I be able to press play and get some sort of activity? (like when I have the CD connected to an external source)

Tried a 2.5A power supply with no luck. The PC-Engine itself works fine in the IFU.

[MNKyDeth]

Are you using two power adapters or are you using the power adapter cable that goes from the CD-Rom 2 to the PCE and only using one power brick?

[atman]

Are you using two power adapters or are you using the power adapter cable that goes from the CD-Rom 2 to the PCE and only using one power brick?

Im only using one powerbrick, I dont think its possible to use more. One in the IFU. The power connections are blocked by the IFU so there is not possible?
The Super CDROM2 have a separate plug i think?

[MNKyDeth]

I didn't realize, I thought you meant the Super CD-Rom 2 pictured below.
https://commons.wikimedia.org/wiki/File:PCEngine_FirstModel_with_SuperCDRom2.jpg

I knew you were using the IFU but thought you swapped it out for the above. I am however not familiar with the IFU in any way as I have not worked on one. Sorry.

[atman]

I have managed to get some readings from the 30-port connector.

Found out that 21, 22, 30 are ground and 5V are pin 20,27.

Checked the CDROM-unit and it looked right.

But it makes no sense on the IFU-side of the connector. Like an entire row (lower) are +5v, and the ones that is supposed to be +5v are like 8v.

Something is off with the IFU.

Before i brought the working CDROM a non-working was included in the setup. And when I tested it the diode on the IFU did not ever lid up. When I removed the faulty CDROM it the IFU led lit up again.

Some sort of short in the junk CD that made the IFU break is my guess.

Changed the 7805 to an 1.5A, checked all caps for short but it seems fine.
Anyone have a suggestion what have happen with the IFU? Where to look next?
As mentioned before, the console part of the IFU works well.

[Keith Courage]

Unfortunately I've seen this problem happened both ways. Meaning the problem could be the CD drive or the problem could be the ifu. It's too bad you don't have a spare of one or the other to be able to test to find out which one is the actual problem.

If you don't know anyone that lives closer to you I'd be willing to test the CD drive for you if you want to mail it out. That way you could at least narrow down if the problem is the CD drive or the docking station. I am in the Chicago area.

[atman]

I have a spare CD, but I belive that one could damaged the IFU. Brought a confirmed working CD. The IFU can have damaged the working CD aswell... I decided to buy another IFU cause they are cheaper and it quite easy to find a working tested one..

I live in the Sweden area so its quite hard to find a test rig. Thanks for the advice. Ill get back in this matter..


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[Fidde_se]

Does the CD-ROM2 power on when in the IFU?

The PCE part and the CD part have different power regulators, So hucards can load up great while the CD doesn't even lit up.

In that case IC118 comes to mind, then there's another one that's has resistor controlled voltage output http://www.retrosampling.se/Temp/IFU-30/IFU-30%20Main%20Board%20PCB.jpg

[atman]

Thanks for the info.

The CD is dead in the IFU, but works standalone so to speak.

IC118 is the voltage regulator that I changed for a 1.5A. You said that they get power from different regulators. IC118 controls the CD part or is it the resistor regulator?

Have any idea where the resistor regulator is located?




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[Fidde_se]

TR101 was the regulator for CD part, right behind the 7805 that has the heatsink on it.

http://www.retrosampling.se/Temp/IFU-30/IFU-30%20Components.txt

[atman]

Aha, the transistor without the heatsink, will make a check what that outputs..


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[atman]

Aha, the transistor without the heatsink, will make a check what that outputs..


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[Fidde_se]

This is since the CD-ROM2 is standalone and works on PC8801 and has its own 7805 regulator therefor it's getting higher voltage separated from the rest of the IFU.

Never measured TR101 but I guess it's goes directly to the power input and delivers 9-10v to the CD-ROM2 connector, nearly acting like a surge protection from the incoming power on the IFU towards the CD part.

[atman]

Think one pin on the cdrom interface. had like 8.5v when I checked yesterday. Dunno what the 7805 inside the CD is rated for correct input.
Tried 10V 2A input and 12V 3A in the interface with no luck..


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[Fidde_se]

Both of those voltages should have worked.

It doesn't need any of the data lines to work standalone in the IFU, so it's either not getting power or ground, we should note that there is a few components in the CD-ROM2 also, it's like a diod, since it's comes from both the DC socket and the CD connector, and it goes into one just being separated with a diod, maybe something more, wolfman on the forum had some trouble with that 2-3 years ago and we checked everything around that back then. So it might work with the DC power but not the the CD connector.....

[Fidde_se]

Here's the picture I draw back then.

https://www.pcengine-fx.com/forums/index.php?action=dlattach;topic=16332.0;attach=1720;image

Here's the discussion:
https://www.pcengine-fx.com/forums/index.php?topic=16332.0

[Fidde_se]

Rereading that then there might be no connection between pin 20,27 and that big red area, the DC plugs traces is rather big but the ones from the CD connector is rather thin, and might burn off quite easily either in the via or the trace that it leads to on the other side hidden under the connector, a wire (like Wolfmans blue line) should fix that right up, test beep if there's any connection between pin 20,27 and that big area.

[atman]

Unscrewed the lid off the CD and it seems its connection between pin 20, 27 and the marked area..

Going to check the IFU tonight.

Is it possible if someone could check The pins from the IFU. Its mostly pin 20 and27 om intrested in..

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[atman]

Powers the IFU with 10VDC, 2A.

IFU:
GND: 30, 22,21

Pin 27,20: to the emitter of TR101

Pin: 9,15,28,29, 30, 22, 21 = 0V
Pin: 20,27 = 9V
Pin: 1-8, 10-14,16-19, 23-26 = 5V

I really dont know which is "data" from the CDROM-ext port, there are many ports that are at 5V, dont know if 5V is "high" for the data bus or something.
The big thing is that 20 and 27 shows 9V and GND seems correct.

One thing that hits me is that when I do a measurement on the 9V it slowly decending. Can start at 9V and go down to 8V or something. Could it be that the 9V from that TR101 cant handle load?
It might drop? to.. very low?

Is it possible to get a 9-10V from the input of the 7805 and feed pin 20,27? Or cant it be the "same" power source as the console-part. Does TR101 separate the power lines as you said?

[atman]

I hooked up the multimeter on pin 27 (&20) and when I powered on the IFU I got like 5V, and it was slowly increasing up to like 8V.
When I hooked up the CDROM it dropped to like 1V. So.. Something cant handle the load.

Can I get "fresh" 10V early (like from the DC-plug) and hook it up with pin 27? I mean it should only feed the 7805 inside the CDROM.

[Fidde_se]

Yes

[atman]

Yes

Lovely!
Ill try it out!

Need to cut some traces or does it matter, I mean "backwards".

Also, another question about RGB modding. I plan to RGB mod this unit if I get it working fully.
Can I take sound L+R from the interface aswell, or do I only get sound on hucard-games? Or do I need to take the sound from the RCA L+R?

[Fidde_se]

Best to cut the trace on ifu pcb and take it from DC input directly.

RCA it is, otherwise only hucard sounds would be stereo and ADPCM and CDDA would be in mono.

You do know where in the world I am right?

[atman]

Best to cut the trace on ifu pcb and take it from DC input directly.

RCA it is, otherwise only hucard sounds would be stereo and ADPCM and CDDA would be in mono.

You do know where in the world I am right?

Yes, I figured it would be the safe way to do it, trace from 20 & 27, they are most likely connected in the contact and 1 goes to the power somewhere.

OK , I thought so aswell. Thanks for the input.

I belive you are from Gothenburg, brought a RGB amp from you, am I right?

[Fidde_se]

Right, but I usually don't sell loose amps, I leave that up to Mickris, but if it was in a cable it was definitely me, unless it was for N64.

Then there's LAB23 and Got2Pair.

[atman]

Had some luck, it was the red wire that is soldered near the CDROM2 connector, so it was very easy to cut that trace. Got 10V from after the switch so that functions as original.

And.. It worked!
Really nice!

Have just an PS1 disc available and no TV to hook it up but I can see that it says PC for some seconds after I pressed run. Guess it stops reading when its not a PCE-disc.

Thanks alot Fidde_se for helping me narrow it down.

[atman]

Right, but I usually don't sell loose amps, I leave that up to Mickris, but if it was in a cable it was definitely me, unless it was for N64.

Then there's LAB23 and Got2Pair.

Ya, that was that PCE EXT cable.
Its that 69 pin ext connector its hard to track down, your cable was really nice looking.

[Fidde_se]

PS1 games usually have CD Audio tracks and the first being DATA so jump a few tracks.

[atman]

Yes!, it seems to play the audio.

Yeey. Such a relief.


Now I have a fully working CDROM2 unit heavly yellowed. Also I got the junk CDROM which is bright white.
Dont know if I dare to change the plastic parts.

[Fidde_se]

There's usually no problem exchanging the case