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[Console Repair/Mod Center / Re: PC Engine Duo - White Screen/Multi-Colored Screen]

Shoot. I seen your post too about removing IC520. I removed it and still same results. I got a logic probe coming in to see your advice on checking to see if the hucard pulls high, low and all that just in case I missed something  . It should be here next week sometime.

[Console Repair/Mod Center / Re: PC Engine Duo - White Screen/Multi-Colored Screen]

The ones that were running hot were IC516 and IC518, but I also replaced 519 to be sure (Didn't have enough logic chips to replace IC517, but it wasn't burning hot). The replacements look like they are back to running warmish again.

[Console Repair/Mod Center / Re: PC Engine Duo - White Screen/Multi-Colored Screen]

Thanks wookie.

Thank you thesteve for helping me.

On my AC adapter I'm getting 17v

I checked out almost all IC's:

The Logic Chips (IC516 to IC520) = 5V
Hu6260 = 5.010V
Hu6270 = 5.009V
Hu6280 = 5.010V
Ram Chips (HSMR series) = 5v
IC106 = 5v
IC501 = 5v
IC505 (Pin 1) = 7.77v
IC505 (Pin 14) = 3.243v
IC512 = 5V

I tested some of the caps that are connected to rails and I noticed C961 is getting 4.1v on it's positive side. Is that normal?.

[Console Repair/Mod Center / PC Engine Duo - White Screen/Multi-Colored Screen]

Hi Everybody,

I'm having a bit of an issue here with the PC Engine Duo listed as no power off eBay last week. When I got it, it was mostly recapped by the previous owner (Horrible job).

Before turning it on, I opened it up and checked for any Vcc and GND shorts, but it was fine. 

Grab my only PC engine HuCard (Street Fighter II), slided it in, turned it on and behold white screen. Turned it on and off a few times and I'm also getting purple and yellow colored screens along with multi-colored screen that moves (I hooked up the duo to my capture card). So I thought let me check the CD portion. Took out the hucard, turned it on. Same thing, white screen .

Since the caps were no name or an unknown brand, I swapped them out with a Console5 SMD cap kit and still same thing.

I also tried out other things, but still nothing (Not in order).
Reflowed 6260
Replaced 6270
Replaced 6280
Replaced Video Ram
Replaced Work Ram
Checked HuCard connector for shorts
Replaced logic IC's except IC517 (2 were running very hot - almost enough to burn your finger but replaced all except IC517).

Spent about 3 days straight working on it and for the life of me can't figure this one out . Anybody have any ideas?. Any help is greatly appreciated.




*Edit* Checked all traces of 6270 using the netlist and had 2 bad traces, but symptom's are still there: http://gamesx.com/wiki/doku.php?id=hu6270_netlist

*Edit2* Checked all traces of 6260 using the netlist and had 1 bad trace, but symptom's are still there: http://gamesx.com/wiki/doku.php?id=hu6260_netlist

*Edit3* Checked all traces of 6280 using the netlist and had 2 bad traces, but symptom's are still there: http://gamesx.com/wiki/doku.php?id=hu6280_netlist .

*Edit4* I whipped out the oscilloscope and found that the 6260 is only getting 60hz? (Sounds like it's for NTSC video, but Netlist homepage shows it should be getting 21mhz?. The 6280 is getting 21mhz though).

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

Steve, your a miracle worker!, that was it. Thank you, the sounds working with HuCards

But i got no audio with Far East of Eden except the sound when a dialog pops up just after i press the  run button. Cant get past that dialog but i think i just need to tune the pots a bit more

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

Sorry i know what you mean now. im not getting continuity between pin 8 on the amp from the audio circuit and the side of R321 that connects to it

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

Sorry, i did check R321 and im getting the same voltage reading (0.030).

*EDIT* Ohhh i see what your saying. im not getting continuity between the left side of the resistor of R321 and pin 8 on the audio circuit amp.

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

I can see the power rail (Thick trace) that it links too on the IC506 amp . It seems like im not getting any continuity between the via that connects to pin 8 on the IC506 and the positive lead of C322. One of the 2 vias that connect to C322 must corroded damaged. I can't really check the via that connects to C322 as its underneath the 4558 on the bottom side of the motherboard. Would it be safe to link them together with some 26 awg kynar wire?. The via by C322 did look kind of black.

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

Ok im getting 4.2v on both pins 2 and 6. For C322 im getting 0.030 I don't see any black vias but i am looking

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

Ok just got out everything and this is the results,

Multimeter set to DC voltage

Pin 3 = 3.89
Pin 4 = 0
Pin 5 = 3.88
Pin 1 and 7 = 1.45

I think we are getting onto something

The positive pad on C614 did get lifted and i patched it to the closest via with some 30awg kynar wire

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

Im getting 3.88 DCV

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

Double post, please delete.

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

Ok i busted out the old multimeter and im getting a rating of 7.81 DC Volts on the Opamp when i place the positive probe onto Pin 8 and the negative probe to ground. I thought the opamp died so i replaced the op amp too as well with the RC4558 but still the same result. Is this normal voltage reading?

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

Hi everybody,

I'm in need of help. Sorry about the long post.

I got a PC engine duo on ebay that was described as "Working but no audio" about a month ago. When i received the Duo, first thing i did without testing it was i replaced all the caps with a cap kit i got from console5. After replacing all the caps, the audio was working. Then i proceeded to RGB mod it using the THS7314 method (8 Pin Din, Etc). Before doing the RGB mod it had CD drive issues so i ordered a new laser. After doing the RGB mod i decided to test my Street Fighter II HuCard i just received that day to see if everything was working alright and i noticed i had no sound again. So i looked around the audio circuit i noticed i had 3 caps backwards, C604, C614 and C678 (Audio circuit too) and i corrected them but still no sound. I also redid the 8 Din installation but again nothing . I also tried to clean around the audio circuit with some 99% IPA just in case if there was any cap residue that was shorting things outbut that didn't work out either. A day later after receiving a new HOP-M3, I manged to fix the CD drive back up again with a new laser and with a few pot adjustments (See my post in laser adjustment guide thread) and the CD drive is back up and running. So now i have 2 problems , one is the no audio problem and the other one is a ceramic capacitor at c518 has been damaged somehow. I don't know if it was like that before or if i did it. Would anybody have any ideas on how to fix the audio and 2, does anybody know the capacitor size and value?. I'm starting to think i damaged the 4558 because of the capacitors being backwards. If this is the case, would a RC4558 work as a replacement? (Texas Instruments 4558). Thank you everybody in advance for your time .

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide]

Thank you thesteve,

I managed to get the CD drive working again using a retail disc of Eden of the East. I got CD drive working again by replacing the laser and using the values noted in the link on the 2nd post. I used the last few posts in that thread. I used the DUO-RX readings then used the VR104 value on another post. May need more turning to play CD-R's working but i got audio issues again . Got to fix that first.

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide]

Hey everybody,

First poster here, loving the contents of the forum so far. Hope i can contribute to the forums as much as i can.

I recently received my first PC Engine Duo the other day from eBay but it had audio issues and a full recap has seemed to fix the issue  , but now i got a bit of a problem now with the CD drive. I didn't have any original HuCards or Super CD games on hand so i decided to give a backup a try and the system wasn't reading it well and would boot the game 1/10 times. Afterwards i went to try to make adjustments in small increments with the pots on the motherboard but in the end, i stupidly turned all the pots a good bit and lost track. I normally would busted out my multimeter and used the charts to listed in the first few posts to get back to somewhat normal readings again but i dont know what the 2nd post means by "AB" "AC" "BC". Does anybody what this means?. I have done Gamecube pot adjustments and it was just a simple ohm reading. My multimeter is giving problems so i have to wait intill my next paycheck to get a new one (BK Precision) and also get a new HOP-M3 just in case, but i figured i would ask the necessary questions beforehand so i when i get the multimeter and the new laser, i can know before hand and it bring it back to life and get it running like new again. Can i still revive this PC Engine DUO or is it screwed? .

Thank you everybody for their time and patience.