PCM Sound & Stability Fixes Multicarts - 120 in 1, 138 in 1, 161 in 1 and others.

[nikoskon]

I just purchased one too, and it is a rev.4 as well. I suppose it will be a good idea at some stage to replace the FMZ caps with a better brand, but that can be done late i suppose.

Is it also better to remove C3 completely, or not necessary?

Also, i had read somewhere that the 161 is not really compatible with the MV1. I have just used it on my MV1-1 and it works fine so far. Haven't tried all games of course, but so far so good.

 

[gtsamour]

Hi, I am going to order one of these carts from Aliexpress soon.
What is the best option to buy at this time? Sound quality and problems free wise.

I saw a cart 161 in 1 that it was supposed to have the games in alhabetical order which is nice but I can't find it now.

Any help is appreciated guys, even links.

 

[dragonpt]

I have the mvs 161-1 rev 2 ( comes stock with both pins bridged)
Already did the pcm sound fix ( both 47pf caps)
I see some people removed c3 due to "tinny sound" ?
Could you elaborate a bit more,what you mean?

Any noticeable difference with it removed?

Thx

 

[maki]

Hi all, got an MVS 161 in 1 cart here that will not improve its sound at all, added the 47pF caps bypass, added missing bypass caps on the board, no avail, no improvement at all

Just noticed it is missing its crystal (top right), haven't seen pics on the web yet where it's missing, does anyone know what frequency its swinging at?
I can only read 11ish Mhz, maybe someone knows the precise value and has other tips on what I could try.

 

[ack]

https://www.mvs-scans.com/images/d/d9/Multigame_161_in_1_series_1_bootleg2_b1_front.jpg

Its possible they are using one of the clocks from the edge connector

 

[maki]

https://www.mvs-scans.com/images/d/d9/Multigame_161_in_1_series_1_bootleg2_b1_front.jpg

Its possible they are using one of the clocks from the edge connector

Thank you @ack

I shouldn't be surprised at all that you'd have a scan of a 161-in-1 PCB lol

turns out I'm an idiot, they've soldered the crystal to the other side, swapped it for another one (these crystals are quite common btw.), no change, PCM sound is still useless, mostly noise

https://imgur.com/a/H0LF3Ap

(can't upload MP4s here so I'm linking it)

I'll try to probe it with my analoge scope

 

[maki]

okay, after adding plenty of more bypass caps and polymer electrolytic caps, still no improvement



I got desperate, so even though I could not see a single cold solder joint on these weird flash IC with their even weirder flex PCB, I've decided to reflow them, on the IC side but also on the PCB side, had to cut the rubber that was used to glue the flash ICs to the PCB



PCM sound works now

nevermind the mess, just testing/experimenting, "make it work, then make it clean"

 

[Hansuke]

I have a 100 in 1 multicart that has the same audio issue, sounds get like 200% loud randomly.

Does anyone have pics of where and what caps to put on the 100 in 1 multicart to fix it?

 

[GohanX]

I'm not familiar with the 100 in 1, but most of these carts have the same basic fix: click on the first link in the thread and see which pins he puts the two 47pf caps on and do the same, and then put 100 nf caps around chips with unpopulated spots for them. A surprising number of multicarts have an empty spot for the 47pf caps that just aren't populated.

If the PCBs don't match any of the other carts don't worry about applying the other fixes, those two caps get you most of the way there. I've even fixed a lot of old single game bootlegs with the same 47pf cap fix.