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[Console Repair/Mod Center / Re: Region mod issue, Obey chip (Solved)]

A thousand pardons for the necro-bump, but I just ran into the same issue.

I couldn't get the thing working at all for the life of me, double/triple checked everything.

Reflowed the tiny chip on the Obey flexy-board and it's working perfectly.

YAY and sheesh (what a pain!).

[Console Repair/Mod Center / Re: What parts do you remove before washing a board in the dishwasher?]

Don't run it through the dishwasher and don't use rubbing alcohol.

Take it to the sink, use a toothbrush and dish soap and get every nook and cranny. Rinse the board until it's clean, then blow-dry it for a good while until it's completely dry.

Isopropyl alcohol can interact with the fluid leaked from caps and make things worse.

[Console Repair/Mod Center / Re: [SOLVED] PC Engine Duo - No disc spin: not pots and new laser?]

When I press run on the screen tells me "just a moment" and nothing else happens

* Do you see a laser coming from the lens? (My R199 was bad)
 * Does it try to focus the laser (move up and down)? (One of my BA6290 chips was dead)

For me, each of those was a separate problem.

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

I lubricated the rails and cleaned the gears, and that really reset things (they must have been adding some resistance to read operations). Luckily I went back and got everything working again. It's down to a low hiss that's not really detectable against the background/ambient noise of the room.

(pots)

http://sendvid.com/3dlpl3rt (video)

So far so good.

edit: thanks Keith Courage for the VR104 tip. That got it quiet.

edit: Oddly enough, there's a slight tradeoff between it being quiet and load speeds during track changes. Is that my imagination? I prefer quiet to load speed.

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

@thesteve 90' turn seemed to help. The CD player seems to spin more slowly and at a constant rate. I was even able to use a CDR without any issues.

There is a slight whining coming from what I think is the motor that spins the CD. You can hear it here, but it's very faint ( http://sendvid.com/lqee7hsk ). Is there any way to lubricate or even replace this motor? Does anyone know the part# for it?

I didn't re-lubricate the metal rails after replacing the HOP-M3. I've read that white lithium grease works well, but others have suggested molybdenum disulfide grease or teflon grease works. Any suggestions on what to use?

I'm trying to make any final maintenance changes to the base system before moving on to RGB and region-free mods. Any other suggestions are appreciated.

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

So far so good! Got Valis IV to load properly. Working on the gamepad at the moment. These pot settings seem to work more or less "ok" with the new HOP-M3.

https://i.imgur.com/GHRGzyk.jpg

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

AMAZING NEWS!

I got a pair of BA6290 and replaced the ones on the board. I can now play an audio CD (sort of)! It's definitely having some trouble dialing in the later tracks (it switches to "disc change" after a bit). The first tracks come up pretty quick though.

Edit: The laser lens started trying to focus immediately after replacing the two BA6290, which it had never done before.

I tested my copy of Valis IV, but no luck with that (not surprised). Going to work on the pots next.

THANK YOU thesteve! Not quite working but definitely an improvement!

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

@thesteve - thanks, I've got a couple on order. Will reply once I have them in.

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

Since last week:

Washed the board in soap/water with full dry, system still behaves as before. Laser lights up but no focus attempt by laser.

Replaced several questionable-looking SMT resistors. They all tested fine once removed from the system, replaced with new SMT resistors. No change. Laser still does not try to focus.

It appears that whoever owned this system before replaced several resistors that appeared to be damaged - the stock resistors are marked 103, the new ones are blue and marked 1002 (both 10k Ohm).

Sanity check: What should R295 be? Should it be a 390Ω resistor?

I re-checked the board with my multimeter continuity checker still cannot find a single broken trace or bad contact.

Those missing are normal
The BA6290 is a current input chip, so you won't really see a voltage shift on its inputs
It's outputs go directly to the laser

Any suggestions on where to look for signals that focus the laser vertically?

Or is there anyone with a working PCE Duo willing to post photos of their motherboards? I wonder if the person that tried to repair the board before me replaced a resistor incorrectly. Hell, I wish there were a parts manifest.. something.. anything.

I'm not certain where to track down the signal that focuses the laser unit. I see the pulses for it (see my previous posts) but I don't know the system well enough to track down where the breakdown is..

Thanks again for your help.

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

Hope everyone (in the US) had a great Thanksgiving.

Just noticed L101. Does this look normal?


https://i.imgur.com/6X4W4bt.jpg

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

A few interesting observations (which match the datasheet) -

When I apply my logic probe:
IC102 pin38 makes the cd spin
IC102 pin15 makes the head move right
IC102 pin29 makes the head not move at all

Three H pulses from IC102 pin5 lead to -> R133 (& adjacent side of R145)-> pin 5 of top-board ba6290a.

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

Decided to test a few things.

Using Elenco LP900 Logic probe (forgot to mention that previously).

Unless specified, assume no change on logic probe and no voltage change on multimeter (when the RUN button is hit).

ba6290A bottom of board
pin1 11.1v ("Vcc") H
pin2 5.6v H
pin3 5.6v H
pin4 5.6v H
pin5 5.6v H
pin6 5.6v H
pin7 L, "mute" (per spec sheet)
pin8 5.6v H
pin9 5.6v H
pin10 5.6v H
pin11 5.6v H
pin12 GND, L

Short pin5 and R147 (by accident.. heh), and it spins the CD and moves the head.

ba6290a top of board

pin1 11.1v ("Vcc") H
pin2 10.1v H
pin3 10.1v H
pin4 10.1v H
pin5 7.1V, drops to 6.6V three times when hit RUN. H no change on probe.
pin6 5.6v H
pin7 No signal from probe, "mute" (per spec sheet)
pin8 4.6v H
pin9 2.6v No signal from probe
pin10 2.6v No signal from probe
pin11 2.6v No signal from probe
pin12 GND, L

black CD drive head left-to-right motor connector (pin 1-7, L to R)
pin1 5.6v H
pin2 5.6v H
pin3 0v L
pin4 0v L, two pulses H resetting head
pin5 1.8v H, two pulses L resetting head
pin6 5.5v, H, two pulses L resetting head
pin7 5.6v H

white HOPM3 connector (pin 1-8, L to R)
pin1 2.5v
pin2 2.5v
pin3 5v H
pin4 2.5v
pin5 2.5v
pin6 2.5v
pin7 2.5v
pin8 2.5v

red HOPM3 connector (pin 1-8, L to R)
pin1 10v H
pin2 10v H
pin3 2.5v
pin4 2.5v
pin5 0v L
pin6 0v L
pin7 ~1v, jumps to 1.75v between head resets, then back to 0v
pin8 0v L

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

Should I be looking around CXA1082 (IC102) for anything that could interfere with the laser lens not focusing up/down? Or somewhere else? I checked a number of traces but didn't find anything obvious (I'm hunting blind).

Do you know what pins/chips are responsible for the laser lens moving up/down vertically?

Thank you again so much for your help.

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

That was it, I have a laser now! (But no focusing by the lens.)

R199 (4.7k) had some serious corrosion under it. It didn't have continuity between it and it's test points. So much in fact, that as soon as I started soldering the resistor off to clean it the pads came right off with it. I've got things wired up now with a temporary resistor and the laser light comes on properly.

R199 sits between pin 29 on the CXA1081 and pin 63 of D78C14GF (IC104).

I don't see/hear the laser trying to focus vertically up/down like I think it's supposed to.

Thanks so much! Where to go from here?

Edit: going to guess CXA1082 (IC102) Pin 5 (focus drive output) - this pin does three long H before the system generates an error. It's trying to focus the lens?

Edit 2: The three long High long pulses from CXA1082 (IC102) Pin 5 make it to one end of R133 (1002 marking, 10kΩ) but I don't see the pulses on the other side of the resistor. The other side of R133 just sits H, no change on RUN (at 7v). The 1002-marked resistors all measure in the 8.5-9.5kΩ range when measured on the board.


Edit 3: Following (but not connected to?) R133, I end up at Pin 9 of the top-of-board BA6290A (IC109), and I'm measuring 7V there. When I hit RUN, I see the voltage drop to ~6V and spike three times slowly to ~7.5V. I couldn't figure out how to trace this to a pin that leads to the HOP-M3. I also couldn't use my logic probe because I don't know where to get 7V from the mainboard. Should this be 5V? See Edit 4, which may explain why things look weird here.

Edit 4: The components under the (bottom of board) BA6290A chip - R294, C294, R293, C293 appear to be missing? Can anyone confirm whether these should be present and what values they should be?

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

From my multimeter:

2.5V each on pin 10 & 14, 5v on pin 30 of CXA1081
Continuity on the CXA1081 pins to the board trace holes look OK.

Reading from the CXA1081 (on the bottom of the board) using my logic probe connected to 5v:

pin 1-4, nothing
pin 5 is high, no change on RUN
pin 6 low, no change on RUN
7-15, nothing, no change on RUN
pin 16 high, no change on RUN
pin 17 low, no change on RUN
pin 18 high, no change on RUN
pin 19 high, no change on RUN
pin 20 nothing
pin 21 low, no change on RUN
pin 22 low, high pulse on run, then high pulse on "Please Set Disc"
pin 23, 24 nothing
pin 25 low, no change on RUN
pin 26 nothing
pin 27 H/L (no pulsing, just H/L on my logic probe)
pin 28 low, no change on RUN
pin 29 nothing
pin 30 high, no change on RUN

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

Thank you so much for your help so far. This has been a great learning experience and I would really love to get this thing working.

Edit: did some testing around the CXA1082 by mistake, didn't realize CXA1081 was under the board.

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

I'm still really confused as to why the HOP-M3 doesn't light up with a laser light and why the lens doesn't move up and down to try to focus.

Last night tested these for continuity on IC501 (with my multimeter) and they all look OK.

94   RST
95   GND
96   IC105 PIN46   [SCSI DATA
97   IC105 PIN45   [SCSI DATA
98   IC105 PIN44   [SCSI DATA
99   IC105 PIN43   [SCSI DATA
100   IC105 PIN42   [SCSI DATA
101   IC105 PIN41   [SCSI DATA
102   IC105 PIN39   [SCSI DATA
103   IC105 PIN38   [SCSI DATA
104   NC
105   -> IC103 PIN21
106   <- IC103 RESISTOR PIN22
107   IC105 PIN86   CD DATA (SERIAL)
108   IC105 PIN88
109   IC103 RESISTOR PIN69
110   IC103 PIN24 + IC104 PIN20
111   IC103 RESISTOR PIN77
112   GND
113   IC104 PIN19
114   IC105 RESISTOR PIN57
115   IC105 RESISTOR PIN33
116   IC105 RESISTOR PIN55
117   IC105 RESISTOR PIN35+54
118   IC105 RESISTOR PIN32
119   IC105 RESISTOR PIN56
120   GND

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

Off the CXD1167Q

with multimeter:
5v on pin 33, pin 73

with logic probe:

pin13 - Nothing until hit RUN, then data (H/L pulsing), then stays high with low pulses. Reset to nothing when system is reset via Run-Select.

pin14 - always high, then pulses of low when you hit run

pin15 - nothing, then with you hit RUN, high/low pulses, then stays low

[Console Repair/Mod Center / Re: PC Engine Duo - No disc spin: not pots and new laser?]

• lid up press run (should say to close cover) - OK
• lid down press run (light on, laser on, laser moves to switch and back off switch) - NOT OK. Red LED OK, laser moves to switch and back off OK. BAD: No laser light from lens and it does not attempt to focus (vertical up/down).
• open lid when light on (light goes off) close lid: OK. Red LED turns on, but turns off when the lid button is open.
• press run again without resetting (same as first time): OK. "Please Close Cover".

[Console Repair/Mod Center / Re: Turbo Duo thinks it´s aways closed - Laserunit does nothing]

So glad I found this thread. This sounds exactly like the issue I'm having on my PCE Duo. No laser light, and obviously the CD doesn't spin. The Hu-card slot works perfectly fine and my system has been re-capped.

Is there a known way to test IC501 without an oscilloscope?
And where would you source a new IC501 (NEC D91317GD)?

Thanks!

[Console Repair/Mod Center / [SOLVED] PC Engine Duo - No disc spin: not pots and new laser?]

Hi, first post here. I recently purchased a PC Engine Duo that would "not play disc games". The system itself works fine via composite out and there's audio through the headphone jack. The laser would not move on the rails or make any noise. I owned a TurboGrafx-16 as a kid and always thought the Duo systems were really cool.

I did a full cap replacement and replaced the laser with a new HOP-M3 unit. Once that was done, I tested with a legit copy of JP Valis IV and a retail audio CD from the 90s. Neither of the discs appeared to be recognized ("Please set disc") but the laser unit would jiggle a bit after hitting Run. The rails are lubricated using some of the excess from the old HOP-M3. The motor that moves the laser along the rails works properly - it spins indefinitely if I remove the gear that actually moves the laser towards the "stop" switch.

I then cleaned the pots with electrical contact cleaner. With the power off, I then measured VR102 and VR104 with my measuring tool and I could get values of 1-10k Ohm on VR102 and then 1-20k Ohm on VR104, respectively. I do see voltage going into the CD unit with the main power turned on (after hitting Run); 3v, 3v, 10v, 10v from left to right.

I tried adjusting the pots using the guides on the site (mainly VR102 and VR104), but neither caused the CD to spin. From what I understand, the CD will not spin until the laser has focused on the CD (please correct me if this is incorrect). I tried adjusting a few degrees at a time on VR102, hit Run, waited, reset the unit via Start-Run, rinse, repeat. I then reset VR102 to 1k Ohm and tried with VR104. No change, still get the "Please set disc" and the CD does not spin. I don't have the magnetic "cap" from the lid in place, I'm not sure if that makes a difference?

When the laser unit jiggles a bit left-to-right, I don't hear the laser attempting to focus or move up/down vertically like on a PlayStation 1 - I assume this is because it's all done by hand via the VR10x pots? The only thing I hear is the initial jiggle. The unit does reset itself to it's initial state (far left) if I move it down the rails away from the small "stop" switch. The same thing happens when I swap out for the old HOP-M3 unit. Continuity seems good between the board and the HOP-M3 connections.

Any suggestions as to how to proceed from here, or what to test to confirm everything is operating normally?

Random aside: I've seen references to IC105, IC106 and IC501 failures.

Thanks for your help!

edit: One thing to note - At no time do I see a reddish light coming from the laser lens itself. The laser lens always appears to be clear. I've checked visually and using my phone camera (in case there was a refresh rate/low light level that my eye couldn't detect).

edit 2: I found a post mentioning that the laser unit should be trying to focus on the CD. My unit doesn't ever try to focus on the CD (moving the laser lens vertically up-and-down). It just wiggles left-and-right quickly on the rails and stops. I also don't see any light coming from the laser at all. This suggests to me that maybe one of the ICs is bad? Is there any way to test IC105, IC106 and IC501 with a multimeter? I don't have an oscilloscope, unfortunately.

edit3: I do see 5v on pin1 of IC501. Not sure if that means anything. I've gone through and cleaned any corrosion, including underneath the card slot.

EDIT 4: 12/01 update; The system works perfectly after fixing R199 and replacing the two BA6290. Prior to replacing these, the system was washed in soap/water. I also applied lithium grease to the CD lens rails. The system now runs stable and really well. I ended up 3D printing a replacement HuCard door since mine was missing.