GORDAK 952 Rework soldering station problems

[SuperAman]

I was able to borrow the exact model soldering station that works and I tested it. With my friends board inserted into my Gordak, it started up fine and when I put my board in his the same problem shows up. So the problem is with my board, I will have to take readings of both to determine what the fault is with my board.

[SuperAman]

I replaced both T5 & T6 both are 12v voltage regulator transistors and it is working as before.

[stj]

i wonder why they died?
maybe c11 is bad and they got unsmoothed power!

[SuperAman]

Originally Posted by stj

i wonder why they died?
maybe c11 is bad and they got unsmoothed power!

I will check it. Also the burned area of the board around the 2 18k resistors, could it have gotten burned because we elongated the hose? The standard hose is very short around 70cm and my friend had made it longer by using another hose from a failed Gordak? Or is it because R35 or R36 one of them is 52K and other is 56.6K they are both supposed to be 51K +-5% ? Also the 18K resistors I could not find locally, even used ones from other technicians' junk pile. How many watts are they? When I measure them they are working and measure 18.46K and 18.5K even though their cover has burned off .

[stj]

they got hot because they are under-rated and too close to the board.
if it was mine i would buy larger resistors and put them on ceramic spacers so air can pass around them.

[SuperAman]

Originally Posted by stj

they got hot because they are under-rated and too close to the board.
if it was mine i would buy larger resistors and put them on ceramic spacers so air can pass around them.

Ok thanks. I can't find 18k ohms here so can I use 25K ohms 2watt or 3watt resistors? Also can I use the rectangular 3watt resistors?

[stj]

you could probably use a single 10k 5w or 7w resistor if you can safely mount it.