As part of providing further examples, I thought id create an issue to cover my experience in converting one of these cheap 60 in 1 jamma arcade pcbs to output in YUV/ Component and update this initial post with refinements.
You may have seen these online for $40-60 in various forms:
They are a great collection of classic games that are emulated in a fpga really well. As they can output in both Arcade 15hz and normal vga screen modes and are powered by molex connector - they are perfect for a conversion project like this.
Arcade 60in1 PCB considerations after measuring with a scope:
R,G,B via VGA socket = 0.7v pp (when connected to device)
R,G,B via Jamma pin = 1.4v pp
Csync via Jamma pin = 3.3v pp
Parts
1 x dek transcoder pcb (fully assembled with cables to tv etc) - see below for specifics.
1 x 12v external hdd power supply (typically 1.5A) - these are used to power external usb hdd enclosures.
1 x pico atx psu (low wattage) with molex connector to power arcade board
3 x 75 ohm resistors
1x 1k ohm resistor
1x Arcade joy stick (cheap sanwa clones work well)
5x arcade parts buttons (or whatever microswitches you want to substitute)
1x jamma harness
Connecting arcade pcb to transcoder. For this section you will need to reference the standard jamma harness pinout - easily found via google.
You can do this one of two ways either via the vga port on the arcade pcb (using a female vga 15pin socket) or taking the rgb signals from the jamma harness.
if you take the rgb signals from the jamma harness pins, be sure to add a 75 ohm resistor in series for each r,g,b line before connecting to the rgb inputs of the transcoder pcb. This arcade board seems output a lower than normal peak to peak voltage for each signal which is why low resistor values can be used.
if you take the rgb signals from vga port on the arcade board you do not need to use these extra 75ohm resistors (as they are already on the arcade board for vga)
Note : The 75ohm resistors act as a voltage divider with the 75 ohm resistors on the transcoder pcb - bringing the rgb signals into the 0.7 p-p range.
csync is taken from jamma harness - I used a 1k ohm resistor in series from the jamma pin before connecting to the video in of the transcoder pcb (this will bring the signal down to well under 0.3 p-p when used with a 75 ohm resistor at R13). I found this worked well for me and produced a very stable picture when used with lm881. Note: you can take csync from the vga port instead (pin 13 on vga is csync when the arcade board is set to 15hz) but you will still need the 1k ohm resistor.
Audio mono (+)and (-) may be wired directly from the jamma harness audio pins on the transcoder pcb. You can then wire the (+) to both left and right audio sockets and (-) to ground of the socket to tv. Alternatively you can use the 3.5mm audio jack on the arcade board. WARNING - while using the jamma pins for audio worked for my setup - it recommended to attenuate the audio to pre-amp levels using a simple addon circuit (these can be found on ebay for a few dollars) to minimise the risk of blowing the tv speaker (my 60 in 1 had been set to only 50% volume ).
You will need to wire up your joystick and buttons as per the standard jamma pins if you intend to play ;)
Considerations for the transcoder pcb:
LM1881 is optional (incl. associated resistors etc) as you have csync being provided from the source. You will need bridge the points on the transcoder pcb (see bridge symbol) where the lm1881 sits if you omit it. Also you will not need the 470 or 1k ohm resistor on input in this case.
I kept the LM1881 in my version as it kept a more stable picture on my crt but it depends on how fussy your crt is.
I also amended the following resistor values:
R12 = 470 (470-500R seemed to give the most stable picture quality for arcade pcb)
R13 = make sure is populated with 75 (as it will be used as a voltage divider)
Additonal notes:
When all done and tested, turn off your crt for 30mins rotate your crt to the vertical position turn on and enjoy some classic arcade games on your consumer crt! (Waiting 30mins is for the tv to cool down and the degaussing coil inside the crt to reset any color issues from rotating the tv).
Here is an example (I housed mine in a plastic clear case and added 15pin sockets for joysticks)
dekkit
commented
4 years ago 
As part of providing further examples, I thought id create an issue to cover my experience in converting one of these cheap 60 in 1 jamma arcade pcbs to output in YUV/ Component and update this initial post with refinements.
You may have seen these online for $40-60 in various forms:
They are a great collection of classic games that are emulated in a fpga really well. As they can output in both Arcade 15hz and normal vga screen modes and are powered by molex connector - they are perfect for a conversion project like this.
Arcade 60in1 PCB considerations after measuring with a scope:
Parts 1 x dek transcoder pcb (fully assembled with cables to tv etc) - see below for specifics. 1 x 12v external hdd power supply (typically 1.5A) - these are used to power external usb hdd enclosures. 1 x pico atx psu (low wattage) with molex connector to power arcade board 3 x 75 ohm resistors 1x 1k ohm resistor 1x Arcade joy stick (cheap sanwa clones work well) 5x arcade parts buttons (or whatever microswitches you want to substitute) 1x jamma harness
Connecting arcade pcb to transcoder. For this section you will need to reference the standard jamma harness pinout - easily found via google.
Considerations for the transcoder pcb:
I kept the LM1881 in my version as it kept a more stable picture on my crt but it depends on how fussy your crt is.
I also amended the following resistor values: R12 = 470 (470-500R seemed to give the most stable picture quality for arcade pcb) R13 = make sure is populated with 75 (as it will be used as a voltage divider)
Additonal notes:
Here is an example (I housed mine in a plastic clear case and added 15pin sockets for joysticks)