Another 6 slot with sound probs

snkdan · Jun 26, 2005

Hi all,
I have a six slot pcb that has good clear sound on slot one, the other five slots have no sound. Once it rotates through the six carts when turned on the first slot looses sound as well. The picture is good for all six slots, all the voltages are good, i have cleaned all the slots and carts, can see no damaged or broken tracks or solder joins. Any ideas?
Thanks for you help,
Dan

chris1 · Jun 26, 2005

What's the 5V+ set at?..It still may need to be raised as some 6 slots seems to need just a tad more voltage to work properly..

....................
Also,Try clearing the Back-up Memory in Hardware Test..

NOTE: a Bootleg cart can cause this......... and some carts don't seem to like to work with others properly..
Try another cart line-up....also try the 6 slot with 1 to 6 carts in it..Try two,then three etc..

snkdan · Jun 27, 2005

I checked the voltages, it's 5.1v and 11.9v at the pcb and cleared the memory. It doesn't make any difference when I change the order of the carts or use old or newer ones. It still has sound on the first slot only when first turned on then once it rotates through the carts, the first slot looses sound. I tried with two to six carts no change. I guess I could use it as a massive single slot (kidding).
Cheers,
Dan

snkdan · Jun 28, 2005

Hi all,
I've tried every thing I can think of, cleaning all the connectors (jamma and pcb), cleaned both pcbs, carefully checked all the tracks and solder joins, checked voltages and power supply. The problem is beyond my limited electronics knowledge. Might be good for spares?
Any ideas on repairs?
Thanks,
Dan

chris1 · Jun 28, 2005

Maybe raising the voltage just a tad might help..as it seems 6 slots seem to need more voltage..

Need to check with ttooddddyy to see what he would suggest(how high)to raise it..

I think you problem may be at the 12V as 11.9v at the pcb seems low..

A problem with the 12V will lead to the sound going out..

snkdan · Jun 29, 2005

I'm going to order a new 15a power supply (i need a good spare), but i've swapped the six slot with the working one in my six slot cab and it still has the same problems. The cab has a good 15a power supply. Maybe the problem pcb is drawing too much current? I'll give the new power supply a go and let you know what happens.
Thanks,
Dan

chris1 · Jun 29, 2005

Cool LMK..

NOTE: this is the direct replacement for an MVS Dedicated US cab...

http://www.happcontrols.com/powersupplies/80007200.htm
This one can be used to..
http://www.happcontrols.com/powersupplies/80001500.htm

If you don't have the plus to plug into these then they can be a pain to put in..

Me= I've always had problems with standard type Jamma Power Supplies.
Two of my US MVS cabs came with them and both power supplies were problematic..

After putting in the direct replacements no more problems occurred..

http://www.hardmvs.com/html/powerSupply.htm

snkdan · Jun 29, 2005

Thanks for the info, i've ordered a jamma 15a power supply as my cab is an Australian LAI dedicated MVS 6slot cab. Its wired to suit the jamma type psu and these are easy to get hold of in Oz. I'll give it a go and post the results.
Thanks,
Dan

snkdan · Jul 13, 2005

Hi all, I managed to find another six slot that would continuously reset when powered up. Got it cheap. I used the top pcb off this one and the bottom pcb of the other and got a good working 6 slot and a lot of left overs. Still using the original power supply, however this psu can only supply enough for 3 carts any more and it starts resetting. Lucky the 15amp psu is on the way.
Cheers,
Dan

ttooddddyy · Jul 13, 2005

snkdan said:
Hi all,
I have a six slot pcb that has good clear sound on slot one, the other five slots have no sound. Once it rotates through the six carts when turned on the first slot looses sound as well. The picture is good for all six slots, all the voltages are good, i have cleaned all the slots and carts, can see no damaged or broken tracks or solder joins. Any ideas?
Thanks for you help,
Dan

Did you recenty get the board in this condition or did the fault recently develop ?

The MVH6 will draw typically 5 amps.

Do not wind the 5 volts much above say 5.2 volts max on any board. You should be measuring at the board, not the psu as there will be voltage drop in the harness.

snkdan · Jul 13, 2005

I got the original board with sound problems (had no sound). I changed all the caps on both boards as a couple on the output of the amp had failed. Ended up with good clear sound on the first slot only, was unable to find any other faults.
Got the second not working six slot and used the top pcb with the bottom from the first and luckily it worked. I knew the psu I'm using to test was no good for a six slot as it couldn't power my lai six slot cab.
Dan

ttooddddyy · Jul 14, 2005

With those sort of faults (sound or gfx screwed only on some slots) check the dozens of LS244,245 and 251 ICs on the top board for signs of overheating, you may see cracked surfaces on one or more of these. Also run it for a while and touch them to detect if any are running hotter than the others, that may be an indication of a faulty chip.

snkdan · Jul 14, 2005

Thanks ttooddddyy, I now have two good working 6 slot motherboards. One in my 6 slot cab and one to go in a empty 25" cab I have.
When I get time I'll have a look at the other as it now has faults with both pcb's. At the moment when it is powered up all it will do is continuosly reset. It has had a lot of work done to it, looks like some one was chasing a sound fault as most of the components in the sound circuit have been changed or at least resoldered(ym2610, 4558, ym3016, ha13001, 2066d and lm324). The soldering work in places is not too good, I'll resolder what I can and check the tracks around the new work. Hopefully I can get it to power up then I can check the ic's on the top pcb as you mentioned.
I'll let you know how I go.
Cheers,
Dan

Another 6 slot with sound probs

snkdan

n00b

chris1

POCKETBIKE NUT,

snkdan

n00b

snkdan

n00b

chris1

POCKETBIKE NUT,

snkdan

n00b

chris1

POCKETBIKE NUT,

snkdan

n00b

snkdan

n00b

ttooddddyy

PNG FTW,

snkdan

n00b

ttooddddyy

PNG FTW,

snkdan

n00b