blastocystosis Posted July 7, 2010 Share Posted July 7, 2010 This was at a family members' house for awhile and I finally got it back here with me. I went through and got all of the dust and what not off of it. But it's still got this corrosion that I can't get off with either 70% isopropyl alcohol or Brasso. I think the motherboard may be fried but I'm not sure. It simply doesnt turn on when I hook everything up. Any help would be appreciated. Here's photos of it. Quote Link to comment Share on other sites More sharing options...
A.J. Franzman Posted July 8, 2010 Share Posted July 8, 2010 (edited) That board does not look bad at all. I've had much worse boards with lots of water damage and heavily rusted main shielding, which still worked. Have you checked the basics, such as: is the wall wart actually providing power to the board? When plugged in and the power switch is on, does the voltage regulator have 8-12 VDC on its input side? Does the output side of the voltage regulator have 4.75 to 5.25 VDC? BTW, brasso is not recommended for cleaning electronic circuitry. It contains ammonia, which is corrosive. There is no need to clean any surface rust or finger marks from the silver-colored shielding. Edited July 8, 2010 by A.J. Franzman Quote Link to comment Share on other sites More sharing options...
Retro Rogue Posted July 8, 2010 Share Posted July 8, 2010 That board does not look bad at all. I've had much worse boards with lots of water damage and heavily rusted main shielding, which still worked. Yah, but I'd like to see the actual main pcb - i.e. what's under the shielding. Didn't see that in the picture. Could be as simple as a cold soldering point. Then again, the RF portion's shielding looks rusted, could be something in there then that's causing no picture. BTW, brasso is not recommended for cleaning electronic circuitry. It contains ammonia, which is corrosive. There is no need to clean any surface rust or finger marks from the silver-colored shielding. Although if you wanted to remove it, take off the shielding and submerge it in white vinegar for an hour. Scrapes right off. Quote Link to comment Share on other sites More sharing options...
pags35 Posted July 9, 2010 Share Posted July 9, 2010 This was at a family members' house for awhile and I finally got it back here with me. I went through and got all of the dust and what not off of it. But it's still got this corrosion that I can't get off with either 70% isopropyl alcohol or Brasso. I think the motherboard may be fried but I'm not sure. It simply doesnt turn on when I hook everything up. Any help would be appreciated. Here's photos of it. I'm not sure what you are using to hook it up either. Is it directly to a TV (LCD or CRT) or through a VCR. I am just wondering if you can be more descriptive. Do you still get the snowy "white noise" picture or is the screen all black or colored? Also as suggested test the voltage regulator and pin 3 of the RF Modulator for power. The board really does look like it is in pretty good shape so if I had to guess I doubt corrosion really is the problem. Quote Link to comment Share on other sites More sharing options...
A.J. Franzman Posted July 9, 2010 Share Posted July 9, 2010 (edited) Then again, the RF portion's shielding looks rusted, could be something in there then that's causing no picture. I thought the same thing at first, from the top picture, and wrote it in my post #2 above. But then I noticed in the fifth picture, that the top of the RF modulator's shielding is actually mirror-shiny; whatever looks like rust in the top picture is actually a reflection! So I edited that part out of my post. Edited July 9, 2010 by A.J. Franzman Quote Link to comment Share on other sites More sharing options...
blastocystosis Posted July 10, 2010 Author Share Posted July 10, 2010 Thanks guys. It's hooked up directly to the TV with an atari coax adapter. When I turn it on it's just still snow. I'm not sure if it's turning on at all. I'm still new to this so how exactly do I test the voltage and all of that? Quote Link to comment Share on other sites More sharing options...
Retro Rogue Posted July 10, 2010 Share Posted July 10, 2010 Thanks guys. It's hooked up directly to the TV with an atari coax adapter. When I turn it on it's just still snow. I'm not sure if it's turning on at all. I'm still new to this so how exactly do I test the voltage and all of that? Hate to sound like one of those call center guys in India, but did you flip the switch on the tv adaptor to game/computer (whatever is listed on there)? Quote Link to comment Share on other sites More sharing options...
pags35 Posted July 10, 2010 Share Posted July 10, 2010 Thanks guys. It's hooked up directly to the TV with an atari coax adapter. When I turn it on it's just still snow. I'm not sure if it's turning on at all. I'm still new to this so how exactly do I test the voltage and all of that? Do you have a voltmeter of some kind? The voltage regulator is the black chip on the lower left hand side of the board with three pins and a screw in it. the top pin should be about 9v, the middle pin is ground (0 volts), and the bottom pin should be about 5 volts. You read the voltage by using the two test clips on the voltmeter. Make sure it is set for DC voltage. Put the black test clip to the Ground (0 volts), I usually use the Rf modulator case. Then put the red test clip to the top and bottom pin of the regulator to test each of them and see if you get the proper reading for both of them. I would also do the same with the power switch and jack. same thing, black test clip to Ground and red to the switch/jack, see if you are getting 9v for that as well. Quote Link to comment Share on other sites More sharing options...
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