mv-1b no sound

pier

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Hello, i opened a new tread to receive help to consolize my first mvs, But before starting to consolize it i must fix mainbord no sound iusse. This motherboard was sold me for really cheap money with no sound, i opened it and i found that on motherboard slot1b ym2610 pin 14 was soldered with a wire to cartridge b50 pin because the trace was cutted, i removed the wire and rebuild the trace with a little piece of wire. After that i checked that the game was running well without sound and i entered into service mode to test the audio but there are no sound test menu. I checked caps for someone blown but they are all ok, i would like to check the ym3016 but i cannot check it because i cannot test sound into the test menu. :(
 

Atro

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if you dont have a z80 error, great chances are that the problem is in the amp circuit, which is better.
 

pier

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it means that i must change caps? The main iusse is that there are no sound test menu. that is something strange.
 

Atro

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if i.e. the opamp fails or dac, you wont get any sound.
it means yes, you have swap something. unless that there is another dead trace around.
 

NexusX

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If you are having a problem with the amp circuit I have a few easy Amp build PCBs available. I can send you one if you pay for shipping (as long as you are in the US). Probably a few stamps worth. O
 

pier

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if i.e. the opamp fails or dac, you wont get any sound.
it means yes, you have swap something. unless that there is another dead trace around.

So, i need a starting point first. I read on another forum that clearing backup ram could be helpfull but i have already done that. After that i could "You can probe pin 4 of the TM3016 DAC (while self test audio is running) with just a logic probe with beep functionality." But self audio test doesn't exist in this console service menu. I could try to probe it with cartridge inserted but it is a little bit tricky but doable. In this case i must build a probe to do it.
 

BIG BEAR

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The easiest fault would be the volume knob may need to be replaced but if you hear the amp (a slight humming sound) as you adjust it then It's probably the z80 chip.The 1b doesn't give you the z80 message if I'm recalling correctly. Your best bet would be to place a dip socket on it via the bios masta so you can use the diagnostic roms to locate the problem.
BB
 

pier

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The easiest fault would be the volume knob may need to be replaced but if you hear the amp (a slight humming sound) as you adjust it then It's probably the z80 chip.The 1b doesn't give you the z80 message if I'm recalling correctly. Your best bet would be to place a dip socket on it via the bios masta so you can use the diagnostic roms to locate the problem.
BB
i will do it, hoping that the carrier will not be italian post. by the way i was reading the mb service manual and the sound test option isn't here so i assume that is normal.
 

pier

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The easiest fault would be the volume knob may need to be replaced but if you hear the amp (a slight humming sound) as you adjust it then It's probably the z80 chip.The 1b doesn't give you the z80 message if I'm recalling correctly. Your best bet would be to place a dip socket on it via the bios masta so you can use the diagnostic roms to locate the problem.
BB

I hooked the mvs to the tv with retroelectronik pro jamma adapter, from tv speakers i cannot hear anything if i rotate the volume knob but if i connect cellphone headphones i can se a stable audio noise and if i rotate the knob i can hear some different noises.
 

BIG BEAR

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You will not have a sound test for that motherboard and it is normal for that particular board.Again,try replacing the Z80 because from your response it seems like your amp is working fine.
BB
i will do it, hoping that the carrier will not be italian post. by the way i was reading the mb service manual and the sound test option isn't here so i assume that is normal.
 

BIG BEAR

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Hi, i am having iusse finding an european seller for the 84C00AM-6, the only one is spanish who sell the TMPZ84C00AM-8, it is compatible with the 6?.
I'm really not sure if you can substitute the 8 for a 6 frequency. Ebay china has the correct chip avilable.
BB
 

pier

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I'm really not sure if you can substitute the 8 for a 6 frequency. Ebay china has the correct chip avilable.
BB

as i can see from the datasheets the difference is 6 mhz and 8 mhz. but i found a game gear for the same price so i ordered it and used the same cpu but it has no audio.
 

BIG BEAR

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You swapped out the 84c00am-6 and replaced it with the same chip and you still get no sound? OR did you use the tmpz84c00am-8?
Did you check the traces at that location?
BB
 
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pier

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i swapped with the game gear cpu that is the same. I was thinking at the ym2610, there was a trace cutted and pin14 lifted and wire soldered to upper b51 cartridge slot. maybe is this one faulty?
 
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BIG BEAR

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You are going to have to check the traces at the z80
BB
 

pier

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i cannot find where z80 pin 1 (a11) should be connected to.pin 7.jpg As you can see the pin 7 of the slot1b has a trace belove the connector but i cannot find the right trace.

I found every trace and theey are all connected

1 a54 down
2 Neosdrt 34
3 Neosdrt 35
4 Neosdrt 36
5 Neosdrt 37
6 Neosdrt 39
7 test point
8 test point
9 Ram7 15
10 Ram7 16
11 pc23
12 Ram7 11
13 Ram7 17
14 Ram7 9
15 Ram7 10
16 r79
17 Neosdrt 20
18 nd
19 Neosdrt 29
20 Neosdrt 28
21 Neosdrt 21
22 Neosdrt 26
23 nd
24 r80
25 r80
26 Neogrc 6 – cart b18 down - cart b35 up
27 nd
28 nd
29 gnd
30 Ram7 8 - ym2610 pin 60 – cart a43 down
31 Ram7 7 - ym2610 pin 61 – cart a44 down
32 Ram7 6 – neosdrt 30 – cart a45 down
33 Neosdrt 31 – cart a46 down
34 Ram7 4 – cart a47 down
35 Ram7 3 - cart 48 down
36 Ram7 2 – cart 49 down
37 Ram 7 1 – cart a50 down
38 Ram7 23 – cart a51 down
39 Ram7 22 – cart a52 down
40 Ram7 19 -cart a53 down
,
at this point i can exclude sdr-t because controllers are working and grc2, but it can be ram7 lh5116d-10 or the yamaha 2610. there is a way to test them?
 
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pier

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I have news, i build a diagnostic bios cart with the pop'n bounce bootleg cart, i press D and select/start the system reboot and from tv speakers i can hear distinct beeps it should be 001000 is it related to ram.
 
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Xian Xi

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Oh and Pin1 of the Z80(A11) should be connected to A54 on the cart slot iirc.
 

pier

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you are right about that. today a desoldered the ram chip and soldered a socket and started to search for a cheap replacement, i tested the z80 with the old chip and without it and i have 2 differents errors than yesterday, with the chip i had 001100 and without it 000100. :\

EDIT: is this good for replacement? HT6116-7LL
 
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pier

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I bought a video glitchy mv1fz for very cheap on ebay, i desoldered BR6216B-10LL on ram11 place and socketed it to the mv1b, it but with diagnostic bios and diag cart inserted but no bip during z80 test, when i put unibios e try to boot 161in1 cart there are no sound. :\

ps. i also double checked sram pinout and created a schematic that helped me to find the right traces
(i noticed to have made a mistake on the ram pin 16, the right trace point to z80 pin10, i tried to delete the wrong image but i cannot succeded doing it, may a moderator delete it for me please?)


Ps2. i have putted again the BR6216B-10LL on the socket of the mb and now it give me 001100. yesterday no beeps, today a different error.

Z80<->68k COMM. ERROR (DATA)

Z80 isn't receiving the expected data from the 68k communication I/O port. Most likely an issue with the Z80 data bus or control signal trace to the chips that control the port (NEO-C1, NEO-D0).

Z80 D0~D7 → NEO-C1 SD0~SD7
Z80 IORQ (20) → NEO-D0 IORQ (37)
NEO-D0 SDZ80R (41), SDZ80W (43) → NEO-C1 SDZ80R (84), SDZ80W (85)

how can i check this on the mv1b board?
 

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pier

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Xian: could be a faulty sdr? i have a spare ym2610 but i don't want to swap it before i am sure that neo diag tells me that it is faulty.

EDIT:
1) i desoldered the ym2610, without it the screen is always black
2) after that i placed a new ym2610 but not having a dip 64 socket with 1.778mm i tried to let the chip legs to touch the holes diagonally but with it installed i have full color green screen (not the normal mvs green screen)
3) i placed back the old ym2610 and tested it with diag 0.19. no beeps, no sounds, no errors
4) i placed unibios with a multigame and launched a game, no music, BUT, on jukebox i do receive nomore error, i can select the memory map for chose the music and click it but i cannot hear music.
5) i placed earphone into supergun 2.5 jack and i can hear some noise when i select music from neojukebox
6) the guilty is the ym2610, previous owner broken a trace and soldered pin14 to the wrong place and fried it. every error was caused by ym2610 and interefered with diag bios tests.
 
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