need help identifying a resistor please

[MATTRESS]

The convergence board on my TV went out. It's easily accessible through a front panel, so I pulled it out to check it out.

There's a burnt resistor.

it's light blue, probably about the size of a tic-tac. no color code stripes.

it reads:
1.8OJ (O = ohm symbol)
RNX1
FU 225


I don't know enough about resistors to understand what 1 watt, 3 watt, etc means, or if I should match up the specific size or manufacturer, etc. But I know this should be a 1.8Ohm resistor.

Anyway, I'm trying to tackle this problem myself, it seems to be a common occurence with this JVC projection TV. The board overheats, and usually the chips burn up. I'm hoping I can get by with just replacing this resistor ... so we'll see.

 

[PM650]

Convergence problems are common on projection TVs, usually with units that use STK392-110 chips (or similar). You can replace the resistor, but it may be a symptom of a failed chip, in which case it will just fail again. What you need is a flameproof resistor - you'll notice the resistor that went bad isn't burnt, which is how it is designed to fail. It's either 1W or 2W, you can look to determine that here - click on 'Resistors' category, 1W & 2W have their own subcategories with pics of each.

The convergence diagram I'm looking at here (they're all similar to some degree) shows the low-value resistors as 1W, so I'm guessing that's what you need (1W is roughly tic-tac sized).

 

[keenan]

Looks like a Vishay/Dale RNX series. RNX-1 is now called RNX100; it's rated 2.5W at 25C. The 'J' indicates a 5% tolerance.

1.8ohm is a bit of an obscure value, but should be easy enough to find.