PC Engine PI-TG001 issues

[ScoreAddict]

So I got me a PC Engine from Japan. Not working, "you can't play game". OK.



It arrived in this condition ("you can't clean console?") and with lots of issues. Would not start, only a black screen would show with a hucard inserted.



Three cold solder points around the power input! You could almost pull it out with your fingers. Now fixed.



Gameport, same story, lots of cold solder points. Fixed.



I even replaced the worn out gameport.

Alas, still only a black screen and no picture or sound. The card adapter has been thoroughly cleaned!





Next I replaced the voltage regulator and removed all of the capacitors.






New capacitators were soldered in.

Still - only a black screen.

Any idea what's wrong here and how the fix it?

A colleague of mine suspects the contacts in the card adapter are the problem and that I should switch pin 1 to "high" (with a hucard inserted).

http://old.pinouts.ru/Game/CartridgePcEngine_pinout.shtml

Alas, I have no idea how to do that and he hasn't told me yet. Anyone here knows what to do?

Thank you!

[Ergot_Cholera]

When you say black screen do you mean that the console doesn't power on? If it is working in any way then I think you should get something on screen, even if it is just a blank white screen.
Have you tested continuity across the fuse (obvious )?

[ScoreAddict]

The console does power on and the fuse is intact. And I'm only getting a black screen.

[Necromancer]

You using RF?  If so, try composite off the exp bus.

[Fidde_se]

Bad connection to hucard = white screen (sometimes if you flip the power on and off rapidly it shows green or purple, or some other weird color), same if you have no card in it.

Most other faults also shows white screen...

Black.... and no sound... hmm, could be everything from small nearly undetectable cracks in the board, even under one of the three main circuits to it's not getting power at all, getting 5v out of the 7805? around 4.995 not 4v or 6v.

Worn out cables between slot and mainboard gives white screen also.

[ScoreAddict]

You using RF?  If so, try composite off the exp bus.

I've tried both RF and and expansion bus (via adapter). Same effect! There is definitely a signal from the console, but it's only a black screen.

Bad connection to hucard = white screen (sometimes if you flip the power on and off rapidly it shows green or purple, or some other weird color), same if you have no card in it.

I know. I also expected dirty contacts, but I've cleaned the card adapter very thoroughly (and several times by now).

Most other faults also shows white screen...

Exactly.

Black.... and no sound... hmm, could be everything from small nearly undetectable cracks in the board, even under one of the three main circuits to it's not getting power at all

How about the thing with setting pin 1 to "high"? My colleague was talking about soldering a cable to make this connection. Alas, he didn't say WHERE to solder it to!

getting 5v out of the 7805? around 4.995 not 4v or 6v.

I've put a brand new 7805 into this console.

Worn out cables between slot and mainboard gives white screen also.

I've also checked the connections between the slot and mainboard.

[wilykat]

So there could be issues with chips or RAMs.
DId you check very carefully for bad trace when you replaced caps? Recheck just to be sure, and check that all via's are connecting both sides.  Also maybe flex the PCB just a bit to see if there's any sign of crack or loose chip pin?

[Zero_Gamer]

Could be anything. The board looks pretty corroded. Looks like it was stored in a damp location or something.

[ScoreAddict]

So there could be issues with chips or RAMs.

Worst case scenario.

DId you check very carefully for bad trace when you replaced caps?

Yes, I did. Nothing obvious.

Recheck just to be sure, and check that all via's are connecting both sides.  Also maybe flex the PCB just a bit to see if there's any sign of crack or loose chip pin?

OK.

The board looks pretty corroded. Looks like it was stored in a damp location or something.

Actually, no. The contacts look pretty normal (no corrosion/oxidation around soldering points etc.) and the capacitators may have been old but they were not bad. The board is rather dirty though. But since this console wasn't treated very nicely, no wonder.

[ScoreAddict]

ADDENDUM:

I rechecked with ANOTHER monitor (this time Commodore 1084S)! There is actually a WHITE screen when the console is switched on! (Looks like the old RGB-monitor I used before has some issues with higher contrast output.)

[Keith Courage]

to use the RF your TV needs to be set to 95 or 96 for it to work.

A white screen is no good. Could be that your ribbon cables have fallen apart at the ends so check that first.  or you have a bad Hu6280 chip.

[ScoreAddict]

to use the RF your TV needs to be set to 95 or 96 for it to work.

I know. At this point I'm only using the AV-Out-Adapter.

white screen is no good. Could be that your ribbon cables have fallen apart at the ends so check that first.  or you have a bad Hu6280 chip.

I've checked the cables.

Anyone got an idea in regards to "set pin 1 to high"?

[TheOldMan]

Anyone got an idea in regards to "set pin 1 to high"?

What would be the point of this? Pin 1 is Cart detect...and I don't -think- the pce actually uses that. In any case, setting it to 1 (ie, putting + voltage on it) would indicate no card connected, I think.

If you think its a problem with the cart slot, check for +5V on pin 38. That will tell you if the card is getting power.

...and you are not doing something silly, like using a US card in a JP machine and/or have a region mod set to the wrong region, are you?

[ScoreAddict]

What would be the point of this? Pin 1 is Cart detect...and I don't -think- the pce actually uses that.

The guy who recommended this to me knows what he's doing. Unfortunately, he's not the most reliable of people due to having no time, most of the time.

In any case, setting it to 1 (ie, putting + voltage on it) would indicate no card connected, I think.

You think? So you're not sure?

If you think its a problem with the cart slot, check for +5V on pin 38. That will tell you if the card is getting power.

+5V from ANY source?

...and you are not doing something silly, like using a US card in a JP machine and/or have a region mod set to the wrong region, are you?

Hey, I may be old too, but I'm not silly!

[Zero_Gamer]

So there could be issues with chips or RAMs.

Worst case scenario.

DId you check very carefully for bad trace when you replaced caps?

Yes, I did. Nothing obvious.

Recheck just to be sure, and check that all via's are connecting both sides.  Also maybe flex the PCB just a bit to see if there's any sign of crack or loose chip pin?

The board looks pretty corroded. Looks like it was stored in a damp location or something.

Actually, no. The contacts look pretty normal (no corrosion/oxidation around soldering points etc.) and the capacitators may have been old but they were not bad. The board is rather dirty though. But since this console wasn't treated very nicely, no wonder.

Oh. Must be the pictures. It looks like there is oxidation on several components, and it looks like some of the legs are rusted on a couple of the chips in pic 11/11.