Can someone help me with my test rig ?

Mario246

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Here are a few pictures that I have taken for you to better understand what I am working with.

The only board that gets any response when I boot it up, even though all the boards I used were tested and working on someone elses machine
2h7432v.jpg


This video adapter is from ( http://www.jammaboards.com/store/cga/ega/yuv-to-vga-converter-pcb-gbs-8220/prod_291.html ) and connects to computer monitors.

I also have a RGBS CGA/EGA to TV and Video Composite converter that I cannot get working ( http://cgi.ebay.com/ws/eBayISAPI.dl...z7cqzgk%3D&viewitem=&sspagename=STRK:MEWAX:IT ) I have used it with two different televisions with the same outcome: a white screen or flickering white things moving around the screen with no image present.

Both of them power up, the first one even boots and lets me navigate menus, so I think it has something to do with either getting video to the adapter or from the adapter to the monitors / tvs.
2exbzuv.jpg


Harness also from JammaBoards
5n69zq.jpg


Wiring:
2j35x6f.jpg


mlmv.jpg


I even bought a separate 5v power supply for the video adapters because I wasn't sure if it was getting enough power from the power supply while it was powering the boards. (yeah, I am desperate).

Does anyone have any ideas? Any help is greatly appreciated, I just don't know what else to try.
 
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I think the LED display is telling you that you are delivering 4.4 volts. Turn the white knob on the power supply until you get 5.0 or as close as possible. If you have a multi-tester, I'd also verify that you are getting a true 5.0 out of the power supply. Boards usually won't boot until they see a clean 5.0 volts.
 
I think the LED display is telling you that you are delivering 4.4 volts. Turn the white knob on the power supply until you get 5.0 or as close as possible. If you have a multi-tester, I'd also verify that you are getting a true 5.0 out of the power supply. Boards usually won't boot until they see a clean 5.0 volts.

It gets 5.3 when there is nothing connected to it. When I connect a jamma board I get 4.4 - 4.8 Max. The white knob is turned all the way to the right, it can't go any further.
 
Either something is draining too much power, or your switcher is bad.

Actually, I think the switcher is fine. I think it's more because of those two scrawny little wires he's trying to use to supply the 5v to the board. Try something like one of those bootleg multiboards, they don't draw as much current and should work like that.

-Ian
 
Actually, I think the switcher is fine. I think it's more because of those two scrawny little wires he's trying to use to supply the 5v to the board. Try something like one of those bootleg multiboards, they don't draw as much current and should work like that.

-Ian

I have tried using the cables that actually came with the power supply and then I chopped up these wires to try them as well, neither worked.

I swear I have done everything that I could do at this point. Do you think the power supply is defective or something?
 
It gets 5.3 when there is nothing connected to it. When I connect a jamma board I get 4.4 - 4.8 Max. The white knob is turned all the way to the right, it can't go any further.

For the record, the boards expect 5.0 on the nose in-operation. The voltage drops when under load, that is why there is a dial to crank it back up (or down).

The loads will be different from varying boards, it's a good idea to check the 5 volt whenever you change boards. In this case you also have two boards connected (not that the converter draws all that much power, but it's still extra load).
 
Ok does anyone know how I can get a pc monitor refresh to meet the Mortal Kombat refresh rate (53Hz)? It seems to want to work, but it freezes at the boot screen. Other games work fine though.
 
I read that I could use a line out converter for jamma audio -> tv. Does anyone have any suggestions as to which would be sufficient for testing various jamma boards?
 
Its all up to the conversion board. In my experience it varies board to board. If you are converting RGB to VGA you might want to look at a good scaler product. Or pick up a cheap old Sony broadcast monitor or something that has RGB on a DB9 input, with a nice case like a computer monitor (probably cheaper than a conversion board!) I have one of those cheap chinese RGB to VGA boards too and it really sucks, some games are fine, some dont work, some look like total donkey.
 
You need a "real" jamma harness.

It looks like you have one of those "multicade" labeled harnesses which
may be fine for the multicade boards, but I wouldn't trust it to run any
real boards.

First of all, that harness doesn't have a -5V line.
Many games need -5V in order to run properly, if at all.

Second, the power supply wiring that it does have is woefully inadequate.
Those wires look nice and thick, but they,re only heavily insulated 22 gauge wire.
 
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