Genesis Model 1-Possible Audio Issue?

Hi guys,

Picked up a Genesis Model 1 on eBay, I know mobo is VA6(TMSS). Picked this one because it specifically had better parts for video and audio.

Sonic 1 is in the box. Game works fine except for one audio subtlety. When I get rings, let's say 6, I only hear the ding sound for rings 1,3 and 5. If I crank the audio, I can hear rings 2, 4 and 6 ding very lowly. No other audio I can notice is effected. I have tried audio out of a composite cable and out of the headphone jack.

I am not the most hardware proficient(I have soldered a few times...). I am seeing I most likely need to re cap the board. I do see some gunk on the under side of the mobo from leaky capacitors. However, these capacitors are under a heavy heat sink. I am having a very hard time removing it. It looks like there are some gold or bronze rivets holding it in place? http://imgur.com/JaCBoNT

Anybody dealt with a VA6? Looks like all previous boards had traditional phillips head screws there. I don't think I am skilled enough to deal with rivets....help is appreciated!

 

http://longhornengineer.com/2011/07/17/sega-neptune/ scroll down to where he removes the cart connector.

 

Thank you...I have somebody else telling me that the ones on the heat sink are security screws and not rivets....very confused.

If they are rivets like the cart connector, if I dent them in and remove them with a phillips head, how would I get the heat sink back on?

Sorry, programmer here so I am new to a lot of this. Thank you!

 

Theres no need for security bits on a heatsink. Ive seen some people use screws, i personally would use a screw and nut with a plasitc spacer on the pcb side.

 

Ok, thank you so much. I'll report back this weekend when the caps arrive and see how it all turned out.

 

I've actually had this very same issue with a model 2, and recapping the board did absolutely nothing.

 

Xar, did you ever figure out what the issue was?

 

I'm afraid not, Xeno. Couldn't work it out for the life of me

 

Well...I gave it a shot, think I did more damage than harm. I did get the heat sink off using a drill bit.

However, on the very first cap, I appeared to get all the solder off. As the cap was coming out, the leads snapped and now the leads seem to be super stuck in the holes. I tried for an hour using pliers, fresh solder, etc but I just cannot get them clear. Think I'm going to give up.

 

Get a solder pump. A heated one is expensive but great or a non heated one is cheaper but still works. If using non heated, heat the pad and pin with iron until the solder starts to flow (add more solder if need be) then quickly place the nozzle of the pump over the whole thing and push the button. It should hopefully suck most of the solder out allowing the pin to be removed.

 

Going to give it a shot. Do you think I have done damage to the board or it is worth giving it a shot?

 

Without seeing the board, I honestly cant say.

 

I'll put up a pic in a bit

 

Would this be overkill/bad for a genesis? Thinking about using this as I take my next attempt with the solder sucker.

http://www.harborfreight.com/180-watt-industrial-soldering-gun-61170.html

 

OK, update.

Got the leads out, soldered a cap into that spot. Also desoldered the one next to it and replaced it. I went to fire up the Genesis, the screen jumps and I hear an audio pop(normal, as it was like this in the past), but now I just get a black screen. Any ideas?

 

Pics of where you've soldered. make sure the caps are soldered the correct way around.

On another note, I just got a Megadrive model 1 Va4 without tmss, and sonic one does the same thing for me.

 

I had a mega drive with that fault can be the sony audio amp