Club 80-90 Forums

When as ISCU fails is there a normal or typical failure mode? They are basically a box full of resistors, capacitors, transistors and a couple of chips.

The only thing I have managed to find on a US website was a comment about changing the "usual" failed transistor that overheats and the 56 ohms resistor that overheats ???? Thing is, to properly check whether the components have failed you need to take them off the board and I don't want to take 7 transistors off, plus who knows how many resistors on a trial and error basis. Shouldn't be rocket science to fix, but like anything determining what needs fixing is the big problem!

Ok, what is a ISCU? can you get a circuit diagram for it?.

Idle Stabilization Control Unit.

haven't found a circuit diagram

ooooo expensive arnt they!,have you tried an add in parts wanted? [on this site ].

Have a while back. Got 3 at the moment!!! All don't appear to work in different ways!

Just figure it isn't a massively complicated bit, so should be fixable....... just depends how long it takes!

you could look up "how transistors work" [or something similar] .For a transistor to conduct [work] it will need something like 0.7volt between the base and emitter,but you really need a working ISCU to compare voltages.
good luck.

Fixed my ISCU with a new Power Transistor (there are 2 BD438 Transistors on the board, I had 2 ISCUs which were both knackered, so I took all 4 Transistors off, measured them and put the 2 good ones onto one board, but you can get the bit for about 35p, I just couldn't be bothered to wait for a delivery from RS components!!!)

Hope that bit of info helps others with dead ISCU's

brilliant!!.

Interesting.