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schmake · Joined: 13 Jan 2008 Posts: 29

Hi Guys

I purchased an incomplete Double Pro Fighter from a fellow member here. Got the device today and began to pull it apart to see any visible damage on the mainboard prior to giving it any juice. Some visible scorching where a diode was missing, and a hacked bridge (wire) led me to look a little deeper.

I can see that a cap at C13 has been removed, and also at C38. It appears that even though there are areas on the board, there never was a cap at C17, nor a diode at D3.

What I am looking for here guys is a little heads up as to what size caps were at C38 and C13.

The RAM board appears to look fine at the moment, fingers crossed it is good.

This DBF is missing the adapter to join to the MD/SNES so I will need to make a straight through adapter.... I'm just wondering if this is worth the effort at the moment.

If anyone could provide me with some insight or schematics would be much appreciated

cheers Very Happy

schmake · Joined: 13 Jan 2008 Posts: 29

Well I managed to track down a site with a scan of the top side of the PCB for the DBF at http://www.randomsonicnet.org/workshop/BoardTop.jpg

Cap 17 and Diode 13 aren't on the board.
Cap 38 is a 200pF 50 volt Ceramic Capacitor (identical to others on the PCB).
I will replace the diode 5 with one of my spare diodes for my pinballs (1N4004).
Can't make out the Capicitor at C13. Looking at the datasheet for the voltage regulator beside it (AN7805) it has an input voltage of 35V. Will try something a little less than that for the cap, maybe 25V 10uF

Will undertake the repairs, make a pass through adapter and hopefully I haven't bought a dud and the bad boy will work Very Happy

schmake · Joined: 13 Jan 2008 Posts: 29

It appears that the connector is not a straight pass-through afterall.

There are 2 resistor networks on the PCB. Anyone know exactly why there are there Question

schmake · Joined: 13 Jan 2008 Posts: 29

Replaced all the missing caps and diode on the main. Made my own pass-through adapter (minus resistor network).... and I had no luck. My backyard passthrough could be the problem, but I'm thinking that I need to compare this to a working unit Sad

MottZilla · Joined: 08 Sep 2004 Posts: 765

I'm sure someone here has a DPF and maybe they'll be able to help you.

If you need the connector adapter you can buy the MD one here: http://gamedoctorhk.com/index.php?main_page=product_info&cPath=72_2_19_116&products_id=729

rcade · Joined: 13 Mar 2008 Posts: 30

How did you go about making your own passthrough card? I need one for my MGH...

schmake · Joined: 13 Jan 2008 Posts: 29

Thanks for the heads up Mottzilla, I'm not sure if I want to invest another $30 on what I'm now thinking is a shonky DPF. Would be good to compare against another working board to identify exactly what component may have gone.

rcade: I had some spare double sided PCBs left over, and etched one out myself. I didn't use the resistor network however.
I'm a fan of the laser toner/photo paper method as highlighted in this thread

rcade · Joined: 13 Mar 2008 Posts: 30

Do you still have the layout you printed to make one? Smile

schmake · Joined: 13 Jan 2008 Posts: 29

Sure, here it is. If anyone can see an error please let me know

vgplayer · Joined: 13 Oct 2009 Posts: 1

I am getting a Double Pro Fighter in a few days with both adapters. Let me know if you need anything.

schmake · Joined: 13 Jan 2008 Posts: 29

DoctorBackup · Joined: 14 Aug 2005 Posts: 265

schmake · Joined: 13 Jan 2008 Posts: 29

Went back to revisiting this unit again. Thoroughly checked the board, and cleaned up some tracks that didn't look quite right and gave the board a thorough overhaul.
Tried to dump the bios, didn't get a clean read. Cleaned up the tin to get a dump to compare to others (haven't done that yet), but this gave me hope that this could be an issue.
Tried again with my homebrew adapter, no joy. Tried with a SMD+ adapter (doesn't fit the case, straight to board) and it works! Haven't thoroughly checked everything yet, but looking good.