Magic Worm - Burnt Resistor Identity

Adzuken

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My father recently received two cabs that were collecting dust in an old building. One of them we managed to get working with some monitor calibration. When we tested the other one - a Magic Worm cabinet - smoke began rising from one of the resistors on the power-supply, rendering it unidentifiable. We made some repairs on the machine, and may have solved the problem, but we can't test it again until we replace the burnt resistor, and we can't replace it until we know what it was.

Here's a picture of the circuit board in question, with the burnt resistor circled. It's fastened to the top of the power supply. If anyone has one of these boards and can tell me what colours are on that particular resistor, I'd really appreciate it. Bonus points for schematics. It's a bit of an obscure cabinet, so I understand if no one has one kicking around to check. Failing a positive identity on the resistor, does anyone know how to check the value of one that has burnt like this?
 
Hell, it may be easier to hack in a switcher than to repair that one. A manual may be hard to find... I looked on my usual manual download places and didn't see it.
 
I have one, boards are packed away right now and it's very late, I'll get back to you ASAP.

Good luck ever finding schematics or a manual for an Italian bootleg.
 
That resistor does look burnt, but I have seen worse. Have you taken it out and tried to measure it's resistance? It may be still functional. That may be only surface damage.
 
I have one, boards are packed away right now and it's very late, I'll get back to you ASAP.
Thanks, I'm really glad to hear that. I was a bit afraid that the cabinet would be forever crippled by one unidentifiable resistor. Though, I guess we could have looked into replacing it with a switcher in that case, as channelmanic suggested.

That resistor does look burnt, but I have seen worse. Have you taken it out and tried to measure it's resistance? It may be still functional. That may be only surface damage.
Actually, I haven't. I suggested it to my father, but he didn't have a multimeter. Now I have the board with me at my apartment to find its identity. I have a multimeter, but no soldering iron to remove it. However, we did have someone with more familiarity with electronics look at it, and he said that it was, in all likelihood, burnt open and no longer providing resistance. I may still test it after we remove it.
 
Finally got around to this, sorry Adzuken. Here it is for anyone else who may run into this problem.

The resistor value on my power supply is 4.8ohms 5% (Yellow, Gray, Gold, Gold).

If you get yours up and running, I'd appreciate voltage readings at the transformer and power supply. Mine isn't working and I'm not sure what voltages should be present and where.
 
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Excellent! Thank you very much. Next time I'm visiting the 'rents, I'll see if I can get everything working. I'm just going to have to find a resistor of that rating somewhere in my pile of them.

I'll let you know if I get it working, and I'll try to get the voltage readings for you.
 
The resistor value on my power supply is 4.8ohms 5% (Yellow, Gray, Gold, Gold).
Is it possible that you mistook violet for gray on the resistor? I was unable to find one of this value in my group of resistors. I checked the electronics store and the lady there told me that the nearest values available were 4.7ohms and 5.1. 4.7ohms is Yellow, Violet, Gold, Gold, which sounds like that might be the one, and I know that violet and gray appear similar on some resistors.
 
Only if it's seriously faded, I looked at it under direct lighting and it was very much gray and my eyesight and color pickup is perfect...for now lol

I'm not sure that a 0.1ohm difference is going to make a difference anyway, not in a basic power circuit like this at least.
 
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