Not that I know anything about this device... A lot of devices have all indicators turned on by hardware when the internal microprocessor is reset (perhaps by having a PIO-type chip driving TTL buffers that drive the LEDs, so on reset the I/O lins all become inputs (high impedance), the inputs to te buffers float high, and the LEDs go on). One of the first thigns the firmware does is initialise the I/O chips and set the right pattern on the LEDs. I wonder if the 'power supply problem' here could mean there's a power-fail circuit that resets the control processor. So if a power line is msisign the processor is held reset. Anyway, what I am coming to is that if the processor doesn't run the irmware for whatever reason, all LEDs go on. It could eb a processor, ROM, address decoder, RAM (?), etc problem too. So yes, chec kthe power liens first, always a good idea. A thing can't work without the right power. Then I would see if the procssor is being held reset. See if the processor clock is running. See if the processor is tryign to access the firmware ROM. And so on. -tony

Of course. I am not disagreeign with you, as I said, I would check the PSU first (I always do that, I've been bitten to many times by marginal PSU rails casuing impossible-to-diagnose faults!). My comment was simply what I would check next if the PSU was fine. Right. Another thing that's always worth doing, particularly if the sockets are cheap formed-contact ones. Most of the time if I get problems with those 3(like researign ICs gets it going again) I replace the lot with turned-pin (machined pin). They;re cheaoper than the frustration of having intermittant faults... -tony