Anyone know where I can get a STV8438CV for FMV card?

[AmigaFun]

Hi all

I am looking for a STV8438CV ic that is used in the CD32 FMV cartridge. Anyone know where I can get one from or what else used these at the time? I have already tried the Philips CDi video cartridge that is supposed to have the C-CUBE chip set, but having taken one apart to look, they don't. (They look far better made though than the Commodore FMV cartridge!).

Thanks in advance

[AmigaFun]

I think I have just found some on the internet. Hopefully they are the correct type

[Oli_HD]

Why did you look for that one specifically? Its just a video DAC like the ones found on the miggies motherboard.
Not being mean by the way, just interested. You planning on making a FMV card from the schematics?

[AmigaFun]

Originally Posted by Oli_HD

Why did you look for that one specifically? Its just a video DAC like the ones found on the miggies motherboard.
Not being mean by the way, just interested. You planning on making a FMV card from the schematics?

Hi ya, I wish I had the skill to build one!
What has happened is that my cartridge has a fault on it where the picture loses all colour and goes blue, the ic gets very hot and the colours return to normal when freezer spray is used to cool it. So now that I have found a place that has them I can at least have one to change out the suspect ic. However, it may not be the ic at fault, but maybe the voltage regulation circuit. So anyway I am trying to collect what I need to try and nail this fault.

[AmigaFun]

I replaced the voltage regulator today. The STVxxxx chip still gets hot though. I have found already a replacement STV ic so all I need to do is to remove the suspect ic and replace it with the new one.

Job for another day though!

[rkauer]

ST usually do voltage regulators, which came hot at any rate. Can you tell the part's code prior to replace it?

Replacing a working part will do any harm, but will be a waste of time and money.

[AmigaFun]

Originally Posted by rkauer

ST usually do voltage regulators, which came hot at any rate. Can you tell the part's code prior to replace it?

Replacing a working part will do any harm, but will be a waste of time and money.

Hi Rkauer;

The part number for the regulator was LM7805C, and that runs almost cold. It's the STV8438CV that gets hot to the touch, and as I found earlier, when freeze spray is used on it the picture returns to normal. I have the spare STV8438CV ready to put in, just need to find time to do it.

[pandy71]

Hmmm - maybe solve the problem with current one - how looks on scope area around DAC?
Maybe some heatsink mounted on DAC can help, usually video DAC ore very warm or hot, they work fast with large currents. Sound like some fault around DAC.

[AmigaFun]

Unfortunatly there is no room to fit a heatsink to it. The case is just too tight. It never had one anyway, so should be fine without one, otherwise I maybe covering up the fault. Once I have fitted the new DAC, I will post back with the results. m

I surley can't have been the only person in all this time who has had this type of fault. Or am I just unlucky in this respect :-)



edit: Just realized, I have not tested it if it's just the CD32 being used for games. Hmmm

[pandy71]

Originally Posted by AmigaFun

Unfortunatly there is no room to fit a heatsink to it.

There is always a place for heatsink especially when the chip this size can earn/dissipate 1.8W power...

Find broken CD/DVD drives - many of them have on chips, special thick pad made from special silicone rubber with thermal conductive filling - it is self adhesive and it is used for one purpose - case work as a heat radiator - usually bottom, add some copper plate - should help to spread heat from chip.