I then replaced all of the 104 caps as I suspected an oscillation in the voltage regulation. The three large 2,200uF caps were getting very hot. The board had been working fine until I left it on overnight and then it would no longer give any audio output - the 'coax' and 'locked' LEDs would light appropriately but that was it. Up to now I've been assuming that if anything had failed it would be a cap so I haven't tried removing the resistors - I'll have a go at that as soon as I get some time. I've also removed the cap between pins 23 and 24, again without effect. I then removed the 1N4148 diode and the 100nF and 1uF caps near the 74HC04 and that too had no effect. (In fact, I originally replaced the regulator altogether but that didn't make any difference.) I've removed the regulator and the caps next to it but that didn't change anything. And I sure hope that the ICs itself are not fried too. Like I mentioned before, weВґre dealing with quite low voltages in this device and it is hard to believe that maybe one of these components is damaged but at least I would suspect the regulator to be fried. The 47k resistor between Pin 23 and Pin 20, the capacitor between Pin 23 and Pin 22. Ofc this regulator also feeds the CS8416 at Pin 23 and you need to check the components too: The 1N4148 Diode, the 100k resistor, the 100nF capacitor and the 1в™џ capacitor, if you can still measure a error. If youВґve already removed the regulator and can still measure this resistance, we need to have a closer look at the components around Pin 13 and 14 of the 74HC04

If you have removed both capacitors but can still measure this low resistance, the regulator might be fried and needs to be replaced. I would try to remove both of them and also measure them, if one of them is damaged ( such a error is very rare but not impossible ). Now hereВґs the deal: next to the voltage regulator you will find a 100nF capacitor and a 10в™џ capacitor. The red arrow points on the Vout tap of the regulator.ДҐ7 Ohm measured against ground looks indeed like a short circuit. I measure a ohm resistance of about 477 Ohm between your marked points.

Cirrus logic cs4398 dac chip reviews