REPAIR GUIDE - TurboDuo: Sound Fix

[override]

Is there anyone in here that can replace all the caps in my PC Engine PAC? I already did the majority of them, but got no results at all from changing them. I am willing to pay a lil to get the rest of them swapped out with new ones if that will fix my sound issue I am having. I live in California. Please someone PM me and let me know. I am tired of owning a faulty PC Engine PAC, and want to see it work again someday. The only problem it is having is it had staticy sound coming from the left speaker during games. After changing out a ton of caps it now has no sound fx coming from the left speaker even though music works fine.

Since you have replaced caps you must know how to solder, replace ALL the caps, and test. If you still dont get anywhere then replace the sound balance chips, M5205OKI and M51131L chips. I can PM you a link to buy both chips if you want. If that doesnt fix the sound start replacing OP amps...If you get anysound whatsoever from the left speaker and it fades after a few seconds or minutes of play you can buy some freeze spray from like Radioshack and when the sound dies start squirting the amps and stuff, if one is getting to hot and causing it to die then you will figure out the bad chips.

I wish I could help more....If you ever decide you want to ship the sucker to me lemme know!

[Duo_R]

links to where someone could buy the M chips and the Op amps would be awesome!

[override]

links to where someone could buy the M chips and the Op amps would be awesome!

Sup Duo-R! Long time no talk....Glad to see you back on the forums even if only for a quick question.

I searched high and low for these buggers and believe it or not I found them as single buys on ebay! There were two sellers that carried them: honestcard and littlediode_usa. honestcard seems to have fallen off the face of the earth and who knows if he will find his way back, his M5205 OKI chip was much cheaper than littlediode's but for any matter if you think about it, the fact that you can just buy what you need is nice instead of having to buy a huge bundle of stuff from like digikey.

The M5205 OKI - HERE!

The M51131L - HERE!

and The BA6290A (I recently discovered these two chips are to blame for the cd player not working, I have started a guide already) - HERE!

Oh yeah almost forgot, the op-amps....The op amps in the duo are general purpose 4558 op amps such as this. Any should work!

littlediode is a nice guy, I gave him a whole list of chips from the duo to find out if he could get them and he returned maximum results, if I remember right he could get all of them except the special hu's ofcourse, and the system card chips. Sometimes he takes awhile to respond to questions but he will usually get you a datasheet if you need one and what not! Also he has given me some decent deals on the make an offer button! The last time I ordered I got $6 off what I would have paid! Hope this tid bit of info helps!

Good to see ya again duo....

[Duo_R]

Thanks override, I appreicate the info. I have seen the M chips on ebay, although I thought they were somewhat pricey (I haven't checked your links yet). Anyone have thoughts on the lack of ADPCM? What should be replaced first to fix that?

Duo

links to where someone could buy the M chips and the Op amps would be awesome!

Sup Duo-R! Long time no talk....Glad to see you back on the forums even if only for a quick question.

I searched high and low for these buggers and believe it or not I found them as single buys on ebay! There were two sellers that carried them: honestcard and littlediode_usa. honestcard seems to have fallen off the face of the earth and who knows if he will find his way back, his M5205 OKI chip was much cheaper than littlediode's but for any matter if you think about it, the fact that you can just buy what you need is nice instead of having to buy a huge bundle of stuff from like digikey.

The M5205 OKI - HERE!

The M51131L - HERE!

and The BA6290A (I recently discovered these two chips are to blame for the cd player not working, I have started a guide already) - HERE!

Oh yeah almost forgot, the op-amps....The op amps in the duo are general purpose 4558 op amps such as this. Any should work!

littlediode is a nice guy, I gave him a whole list of chips from the duo to find out if he could get them and he returned maximum results, if I remember right he could get all of them except the special hu's ofcourse, and the system card chips. Sometimes he takes awhile to respond to questions but he will usually get you a datasheet if you need one and what not! Also he has given me some decent deals on the make an offer button! The last time I ordered I got $6 off what I would have paid! Hope this tid bit of info helps!

Good to see ya again duo....

[override]

Thanks override, I appreicate the info. I have seen the M chips on ebay, although I thought they were somewhat pricey (I haven't checked your links yet). Anyone have thoughts on the lack of ADPCM? What should be replaced first to fix that?

Duo

links to where someone could buy the M chips and the Op amps would be awesome!

Sup Duo-R! Long time no talk....Glad to see you back on the forums even if only for a quick question.

I searched high and low for these buggers and believe it or not I found them as single buys on ebay! There were two sellers that carried them: honestcard and littlediode_usa. honestcard seems to have fallen off the face of the earth and who knows if he will find his way back, his M5205 OKI chip was much cheaper than littlediode's but for any matter if you think about it, the fact that you can just buy what you need is nice instead of having to buy a huge bundle of stuff from like digikey.

The M5205 OKI - HERE!

The M51131L - HERE!

and The BA6290A (I recently discovered these two chips are to blame for the cd player not working, I have started a guide already) - HERE!

Oh yeah almost forgot, the op-amps....The op amps in the duo are general purpose 4558 op amps such as this. Any should work!

littlediode is a nice guy, I gave him a whole list of chips from the duo to find out if he could get them and he returned maximum results, if I remember right he could get all of them except the special hu's ofcourse, and the system card chips. Sometimes he takes awhile to respond to questions but he will usually get you a datasheet if you need one and what not! Also he has given me some decent deals on the make an offer button! The last time I ordered I got $6 off what I would have paid! Hope this tid bit of info helps!

Good to see ya again duo....

The lack of ADPCM is caused more likely by the M5205 OKI chip, its the ADPCM processor/Balance Chip. The M41464-10 OKI chips (x2) are the memory storage for adpcm. I assume such as when you sound dies and you still hear the gun shooting or a bomb explode in game thats why, its stores some data in those ram chips. Next would be the sound balance chip M51131L. The next in line would be the two 4558 op-amps, to the left of the RED molex connector for the cd player, if memory serves me correct those follow the M5205 OKI! Then i believe from there is goes onto the back side of the board. I can get more info if ya need it. I have a datasheet for the M5205 OKI but its PDF format so I cant upload it in photobucket. Ill send it to you via Email Duo_R! Times short so gotta go.

[Duo_R]

Thanks, I have another Duo that I am swapping parts with until I figure out exactly what the issue is before I just blind start ordering parts since that can get expensive. This Duo has had every cap replaced, and I think I already did a swap with on of the M chips. This Duo is in great shape now besides ADPCM. I have this project on hold at the moment but will pick up pretty soon on it. Sadly I am doing no more mods once I ship Tron's Duo-R back but always here if anyone has a question or two. Just be patient because I won't be on the forums as much as I used to.

[Duo_R]

Override or anyone, do you know a good source for the M41464-10's? And damn these were a bitch to remove. I thought I had the technique all done then I lifted some tracing!!! It is fixeable but still going to be a pain in the ass.

[blueraven]

This part number for the RAM is M41464-12 not M41464-10, so I Assume it will not work, however; you may want to contact this eBay seller to see if he/she has stock.

http://tinyurl.com/mvdn6k

[Charlie]

"This part number for the RAM is M41464-12 not M41464-10"

The dash typically refers to the speed of the chip, if a 12 (slower @ 120ns) works, a 10 (faster @ 100ns) can be subitituted, but not the other way around.

Charlie

[incrediblehark]

So i replaced the pre and post op-amp caps in my duo mentioned by Dean and Duo-R (4 10uF 16V & 2 22uF 16V) and restored sound to my US duo, but the sound is sratchy, especially when cd and adpcm is playing. would this be another cap issue? there was mention of some more caps to replace (100, 1000, 470, and 220uF caps) near the amp. any ideas about the scratchiness of the audio? i dont really want to replace all of the caps, i dont feel experienced enough to do it.

[override]

So i replaced the pre and post op-amp caps in my duo mentioned by Dean and Duo-R (4 10uF 16V & 2 22uF 16V) and restored sound to my US duo, but the sound is sratchy, especially when cd and adpcm is playing. would this be another cap issue? there was mention of some more caps to replace (100, 1000, 470, and 220uF caps) near the amp. any ideas about the scratchiness of the audio? i dont really want to replace all of the caps, i dont feel experienced enough to do it.

There could be a number of reasons as to why the audio is scratchy, read here for the cd portion of things....

The other could simply be there are more caps that need to be replaced, aswell since you say you dont feel experienced enough to replace all the caps, you could simply have a bad connection to the new caps you replaced. You want to make sure the legs of the caps are pressed down all the way onto the pads that your resoldering to, you dont want them floating in the solder. Bend your caps legs like this ][ on bottom and when you have them mounted straighten them up then reheat one side at a time while applying light pressure on top of the cap to that side. If they sink any then they are "floating in the solder", once they wont go down anymore then they have made solid connection with the pads!

As for the Duo goes all together, I would say if your gonna replace a couple caps then you may aswell replace all of them, its not that hard of a task, if you take your time and be careful as to not lift any of the pads from the board, you can have it done in a day I'd say. You could always hire someone from the boards to do the work for you, myself included! Red Ghost I believe is doing cap replacements aswell. Im not positive on anyone else, but possibly chop5 and blueraven.

[Duo_R]

My experience (and I have seen similar results with others) is that scratchiness means a couple caps leaked on your board and causing intermittent grounding of different pins and causing shorts which creates the scratchiness sounds. The only fix I am aware of is a dishwash method. Do lots of research and reading about before you attempt, there are a couple threads on here on how to do it.

[skevenna73]

One of the kids in the lab had her Tacoma truck keyed today.  It runs all the way down the passenger side.  Does anyone have recommendations for a repair shop?

[Necromancer]

One of the kids in the lab had her Tacoma truck keyed today.  It runs all the way down the passenger side.  Does anyone have recommendations for a repair shop?

May I suggest that you try dying in a fire?

[blueraven]

OK:

Got the Black PC Engine Duo to limp me to the end of Xanadu; now the real fun begins.

I did the sound cap replacement, the 4 10mf caps, and the 1 47.  I used the hi-temp caps just in case becase of the known problem with the heat synchs. It worked fine for about 2 minutes; full sound, redbook and huey music.

All of a sudden there is a heck of a lot of scratching during gameplay, crackling over the voices and occasionally cutting out. Re-booting to the main screen, the deafening scratching continued. I pulled the system apart, and cleaned it with 60/40 alcohol and a toothbrush. I -reset the laser to the origin position to see if that was the issue. Upon re-assembly, the static was really bad.

Here's the problem: there aren't any more leaky caps on the mainboard;

---

EDIT: There was a lot more wrong. I just finished a complete cap replacement, and the problems went away. At least 10 caps were leaking at the original time of this post. 4 22's, the 3.3 under the HOP-M3 (which needs replaced), 2 100's, 2 4.7's and 2 47's. (all microfarads). A good scrubbing with 70% alcohol and a toothbrush took care of the excess electrolytic fluid. Photos posted on the PCE Duo complete cap replacement thread;