ms PacMan PCB Diag Help

Arcade Collecting > Restorations & repair

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ed12:
holy crap was that dirty...
try cleaning and reseating all of the socketed chips
btw u are not getting video at all
to clean the chip legs use a rubber eraser (go slow and careful)
1 at a time reseating them back in there proper sockets and placed the proper way "ie pin 1 to pin1" of the socket/chip

ed

TheMythTheLegend:
K. Hmm ill take your word for it. Could have sworn i saw colors in the vertical and the single line at the top. Could be my imagination.

I will have another go at that tonight.

If all chups except cpu ate removed was there a hatch pattern that should be displayed?

ed12:
no
the board dose not work that way
3 of the most needed chips (to display video of anykind) are the 3 ram chips
normally in sockets, some do some donot have a heat sink on them
but they must be in and working to get video

ed

TheMythTheLegend:
Gotcha. Thank you very much for the much needed info. Will report back tonight what I find out.

Thanks again.

TheMythTheLegend:
Well found a chip with 2 broken legs at r3. Replaced with a spare.

But i got my fluke out and found that I did NOT have voltage running across the large 10000uf caps...

Taking the board out and placing on a table. And measuring cont. Around it... I find that the caps by the audio chip are holding .5vdc voltage... All of the other caps are dead....

So I think I am going to bite the bullet and order a few cap kits and dick around with that for this weekend....

So c3 c10 c8 bad is what i am thinking. On ohms, i should see the caps slowly climb and then reversing would be slowly in the opposite....

I also thought an open cont. Capacitor was faulty to leakage and would not measure voltage.

These big caps read between half a v dc and 1.01v dc... So I am guessing they are shot

I think they are fake chinese parts... Not even a temp rating on Them...

Am i going the right direction guys??

I figure if I am gonna recap the board... Might as well do them all...

Or solder in place with just the tips of leads in and test. Then resolder and cut shorter if it works lol

Im shot. 3 hrs working on this board.... Why oh why this hobby..... Fml

Edit...

Ok my use of some electrical terms is crap, as I was very tired and decided to stop playing with electricity. I will look over and fix my word usage.

Also

I am looking at more in the area of D9-in4735 and Q6-d44vm4...

I am thinking either I have a grounding issue and the c7/c8 10000uf caps are not getting voltage... And the d9 q6 may not be getting ground and sending a signal... Which i did not check last night (need a fking bench setup).

This is where a logic probe would save me...

But then again I had continuity in the same places as my working pacman board.

But I did not check line voltages... Which I should have and written this all down...

Pure speculations... But it is either a ground issue or caps or the d9&q6. As the other side c caps had a .5/.6ish voltage so i would assume ground is good... Atleast on that side

So that would be the "A" solder side ground 7V GND...

Or the 7V at d&4 pins... Which also brings me back to d7&d8 on the phase a of the 7v line....

I need to do some serious testing...

Can anyone tell me if I am atleast tracking this down right?

My connector is a little toasty... Im adding a pic to the album on imgur.

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