30k 10watt ceramic resistor checking and availability

[jalexquijano]

I already swapped the 2.7k ohms 10watt ceramic resistor (R128) on the schematic with a Brand new 2.7k 10 watt resistor. Anyway i am still having problems finding the other power resistor, 30k 10 watt (R129). I guess if i pull it out of the circuit and it still measures 30k and has no noticeable signs of wear or breakdown or crack due to heat then there is purpose of replacing it! Do you concur?

[cjenrick]

https://www.ebay.com/sch/i.html?_fro...istor&_sacat=0

i would up that to 20 W what the heck, engineers run everything hot to save $$$, a penny here , a penny there,

https://www.ebay.com/sch/i.html?_odk...istor&_sacat=0

pc mount? run leads to a sand block R heat sinked on the chassis , jb weld plus tie wraps,

that way you don't cook the traces lie bacon, not that i have anything against bacon, everything tastes better with bacon, even glazed doughnuts,

[Enzo]

It dissipates 5 watts.

How did you decide it needed replacing?

If the 10 watt resistor has lasted 30 years, I doubt it was over stressed by the circuit.

Even if you do replace it, wher did you look? Mouser has a couple choices in stock for a couple bucks each, 30k 10w 1%.
http://www.mouser.com/ProductDetail/...t7t8zDD6eXs%3d

[cjenrick]

5 watts thru a 10 w gets real hot, i bet that resistor looks torched.

you can boil water on a Dale sand block at 50% power,

200 ma thru a 120 10 watt a bubblin>

[jalexquijano]

DO i need to pull it out of the circuit and measure it before considering on replacing it or not?

[cjenrick]

just measure the power supply voltages, if they are within 20% of the schematic then you are alright,

if it were a job i was doing for a customer, i would replace it and up the wattage to make the pwr supply more bullet proof. thermal cycling can sometimes cause leads to become unattached internally, especially with vibration.

since the power supply is responsible for 90% of amp repairs, i am more prone to practice overkill when it comes to service work in that area. yes the pwr supply includes the on/off and std by sw.
and the power cord.

[Enzo]

You only need to remove a part to measure it if you cannot get good readings while it is in the circuit. Is ther any thing telling you it is bad?