New Life Games LLC
Monitor Repair Log and Database. **Arcade and Gaming** => LCD and CRT Monitor Repair Tech Support => Topic started by: oldgeiser1 on December 03, 2016, 11:52:11 AM
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I was fortunate enough to find four NOS tubes for my four game kings. Swapped all of them without electrocuting myself and everything has worked well for several weeks. Now one goes black when it warms up. Let it cool for a bit and it will boot then after a few minutes it goes black with a single horizontal white line for just a second and then it disappears. For the few minutes that it works the colors are good and it looks fine.
Need recommendations please.
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The horizontal line is the vertical collapsing. You might need to recap the board
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Could it be a cold solder joint?
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Absolutely, and easy to shotgun the vertical circuit to find out, but if the board is old enough to need a new crt it is likely old enough to need recapping
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What Chassis are you using?
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This one. I only replaced the tubes because of the burn in. The NOS ones look like new, well, they are.
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I think the 1793 chassis is a lot like the 1492 Ceronix chassis... I have found that 3 different components go bad on these chassis..
First is the LA7851 IC, 1 of these on the 1492 chassis right behind the LA7830 Amp.
http://www.ebay.com/itm/10PCS-LA7851-Encapsulation-DIP-20-CRT-Display-Synchronization-Deflection-/282150341448?hash=item41b1788b48 (http://www.ebay.com/itm/10PCS-LA7851-Encapsulation-DIP-20-CRT-Display-Synchronization-Deflection-/282150341448?hash=item41b1788b48)
Second is the LA7830 Vertical Output Amplifier IC, It's located on a heat sink right in the center of the board..
http://www.ebay.com/itm/NEW-ORIGINAL-LA7830-SANYO-SAME-DAY-SHIPPING-BOX-52-/201523406623?hash=item2eebbb271f:g:vJcAAOSwxH1UDyT- (http://www.ebay.com/itm/NEW-ORIGINAL-LA7830-SANYO-SAME-DAY-SHIPPING-BOX-52-/201523406623?hash=item2eebbb271f:g:vJcAAOSwxH1UDyT-)
Third is the LM324N IC, Low Power Quad Op-Amp, there are 2 of these on the 1492 chassis..
http://www.ebay.com/itm/LM324N-Low-Power-Quad-Operational-Amplifier-Lot-of-10-LIC-LM324N-/182162467103?hash=item2a69baa91f:g:Et8AAOxyVLNTAovH (http://www.ebay.com/itm/LM324N-Low-Power-Quad-Operational-Amplifier-Lot-of-10-LIC-LM324N-/182162467103?hash=item2a69baa91f:g:Et8AAOxyVLNTAovH)
I would also do the Caps, but I have had good luck replacing these other parts in bringing the 1492 chassis back to life.. I believe the 1793 chassis is very similar layout.. If you go to the down load section I know there should be a Ceronic manual.
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Thanks for you're help.
I can pick up another chasis easily so I probably won't spend the time on this one.
Turned the machine on about 4 hours ago and it has been sitting there in attract mode
all this time without a flicker. Guess it just can't stand any more of a load than that.
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If you don't mind me asking, where is heck did you find new CRT's?
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Slot wholesaler in Arizona. Just happened to have 4 stuck away and he let me have them for $25 each, how lucky was that?
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Wow.. Can you say Jackpot!! :reels: :dancing_2:
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This monitor is just weird, maybe possessed.
I can boot it up and it will run all day but put credits on the machine and play
and it flicks off in 15-20 minutes.
What does that tell me?