WG 4900 in a Tron Upright

eh97ac

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Long time lurker here. I am going to look at my second cabinet tonight and wanted some prelim feedback on what to expect. My first Tron had no monitor issues, so I have to ask.

The monitor is stated to be in this condition, "the screen is a little off colour, like someone put a magnet on it"

Degauss, cap kit or other?

TIA
 
Someone could have disconnected the degaussing coil.
Sometimes a person can move the game to another location and have the monitor clear up or by simply rotating the game one way or another.
Otherwise - Manual degauss
Color pot adjustment needed
Cap kit
Or possibly all of the above.
 
Update:Got my Tron home!

I was stunned to see a non-working G07 instead of colorful WG4900. Got a much better price.

F901 & F902 are good. Checking HOT in the morning once I remove the chassis.

New thread for any questions I might have will be started.
 
Your hot will be fine if the fuse is fine. Check to make sure you're getting voltage at the board, and if you are check your B+, you're probably going into high voltage shutdown.
 
Your hot will be fine if the fuse is fine. Check to make sure you're getting voltage at the board, and if you are check your B+, you're probably going into high voltage shutdown.

I only had 5 mins but the HOT is bad, I didn't check anything past that. DMM was showing 0.02.

I should have some time tonight to keep investigating
 
I've got that same problem on my K4915. Dead HOT, fuse is good. Replaced the HOT and VR, only to have the HOT blow instantly. I've got +145VDC out of the rectifier, so based on the B+ voltage (0V), it appears that the fly is bad and taking the HOT and VR with it at power up.
 
Yeah, but we're talking about two different things here. He's got a G07. G07, if the hot is bad, it alllllways takes the fuse, as far as I know. It's tied directly to it!
 
I just looked at the G07 schematic, and the circuits are pretty similar actually. In both, the HOT is located between IC501 and the primary HV coil opposite B+. But the K4900 only has a main fuse (3A F902 in a G07) and not 1A F901 between the rectifier section and the voltage regulator section of the power supply circuit. Is it F901 that blows with the HOT?
 
What usually kills the HOT in a G07, the fly? If so, looking at the schematic I'm not sure what's it's actually protecting besides the VR IC. Are VR IC's a common failure on the G07?

This is an interesting comparison because flybacks are a common problem in an G07, and a rare problem in a K4900. Perhaps the lack of fuse is allowing the VR other components to take the brunt of an out of spec condition, saving the fly. Might be worth tinkering with to see if it makes more sense to jumper out F901 than leave it.
 
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