Resistor fried in central board

Ron Rich wrote:Hi Tim,
Glad it's working---
You are "braver" or, "luckier" then I am ! I would have "tested" ALL "downstream items" prior to power up --
I would suggest installing an 8/10 amp SB fuse in that 1 amp holder--at least for "awhile"---
Ron Rich

Will do, thank you Ron. Yes, sometimes I take chances, wish I was that lucky with the lottery!

Tim

Hey Tim... what about replacing the fuse and then plugging in each board/connector one at a time to help identify what unit is causing the short?
*** Ensure that you power the machine off before connecting/disconnecting any of the components/cables ***

Davester.

Fuse in place now, is correct, and resistor replaced. I've hooked up everything, minus the control and credit unit, and it maintains power LEDs lit, and nothing popping/smoking.

Unless you mean I should hook up the control and credit unit, and slowly one at a time, start plugging in the cables it has/uses? It has the following cables/components that hook up to it:

Playing indicator
Cabinet switch (service)
Centrale unit
Coin acceptor
Key board

So on the off chance the CCU is ok, it could be one of the components that hook up through it causing the draw. I would imagine something may fry first on the CCU before hitting the centrale unit.

I could be wrong, could just be the resistor that fried, was just ready to go and have this happen. Just not taking too much chance plugging the CCU in again, as much as it is not hard to replace a resistor again.

Tim

If the tech has a replacement CCU, I think you're in the clear.
But if he doesn't, you'll have to find what in the circuit of the CCU is causing the short/blown fuse/resistor.
I would unplug the anything that the CCU runs and then plug the CCU and see if you get anywhere through the process of elimination.
Just seems odd that a resistor or fuse "just blows".

Davester.

Davester wrote:Just seems odd that a resistor or fuse "just blows".
Davester.

No, it's not "odd" at all.
A shorted processesor IC chip, op amp, a transistor, or a shorted capacitor can easily cause this condition.
Or.... somebody putzing with electricals that they have no idea about.
I see it all the time on the bench.

Most likely something on the CCU, and not what is attached to it. And for the record, I've not messed with anything, only plugging things in (and replacing the burnt resistor). So unless a previous owner had done anything prior to me, I don't see evidence of that.

Tim

Guyz,
"Resistors" can "go bad", without any other component being involved. This is rather unusual, and it can be the fault of the company that built the resistor, or the company that used it. If the former, it was not built correctly, and is unable to handle the wattage it was "rated at". If the latter, it is running at slightly above it's rating, causing it to overheat, and fail. Most of the time when one fails, "by itself", it opens, rather then shorts--which will, in most cases, NOT, blow the fuse--that's why I strongly suggest that till you determine the exact reason for the failure, you should use a lower value fuse. Ron Rich

I agree Ron. I feel that it was probably just a resistor that was bound to fail. I still am not comfortable hooking up the CCU, but I could put a lower value fuse in and hook up the CCU and see if things remain stable or the resistor blows again. Have plenty spare resistors now.

Tim

Hi Tim,
The point of a lower value fuse is to protect the transformer-- the value of the resistor is nil, compared to what a transformer costs--if obtainable !
Ron Rich

Well, it is definitely the credit and control unit. Hooked it up via ribbon cable to the centrale unit, nothing else hooked up, and pop went the resistor.

NSMvinyl, I contacted them, and for a fair price they said they could fix my CCU. Just strange, probably a transistor or something on CCU causing this.

Tim