Supergrafx white screen

[Jeff]

Hello,I am a new member and I am having trouble with my supergrafx.All I get is a white screen when I insert a game and switch on.Machine has been received capped.Still white screen.Wonder what else could be a miss.Graphic chip blown maybe ?Any help would be most appreciated.

[Black Tiger]

Try the PCE/SGX mode switch (on the back?).

[Jeff]

Hello,I tried the switch first.Definitely not that.Thank you for the reply though.

[BlueBMW]

Is it possible the unit experienced some sort of a physical shock?  Supergrafx are notorious for the mainboard cracking in the middle by one of the support posts.  Cracked traces can cause any number of not working conditions.

[Jeff]

Hello,checked the board and all looks in good condition.

[Bloufo]

Could be a case of that the games are going in too far in the slot. Back them back out until the power lock just barely clears the card, then turn it on.

[Jeff]

Thank you,I will give that a try tomorrow.

[Bonknuts]

I dunno. Sounds like dirty pins on the connector. I've had this happen to my SGX when I didn't play it for a year (the humidity of the swamp cooler during the summers, is the culprit I suspect in my case). Anyway, but yeah, dirty contacts is a somewhat common thing with SGX/PCE/TG16 consoles.

[imparanoic]

check the power supply is correct Output DC 9V 800mA (higher milliamps is fine, but lower will ruin your machine)

[Jeff]

Thank you for the replys.I have cleaned the contacts and power supply is correct.

[deubeul]

Do you have several hucards to test?  Bloufo's advice could be right, sometimes the Hucard position could be picky.

BlueBMW is right too, I once had a crack on the MB of mine because of a not so big shock, the crack was under the card slot and hard to see.

[Jeff]

I have checked the board but will look under card slot.Thank you.

[majors]

... power supply is correct.

I had a Shuttle using a random PSU from a old pair of computer speakers that was rated correctly based on the label. The volts read correct but it never worked. I found another that worked so I can only assume the amps was too low on the first one since it quite old (I could not test that with my multimeter). Is the PSU original? If cleaning and checking the mobo check out, can't hurt to test with another power supply.

I would get a green-ish screen with a slight fade to blue near the top using the "bad" power supply.

[thesteve]

Cracks are most likely
They also crack by the heatsink screws in

[Jeff]

I have another supergrafx and use the psu from that one,so don't think that is the problem.Tried the game cards further out and in to no avail.Thank you for suggestions though.