Post by Deleted on Aug 4, 2022 10:00:29 GMT -5
I have a Pioneer SC-2022 that fails to power on at all.
After a few basic checks, fuses, main power relay, standby +5V, which are all good, I traced the +5V standby to the front panel and checked the power switch itself was good and the clock signal at the display processor was present too. Pressing the power button should result in ACRY and DVCPOW at CN7902 going from low to high but neither change state.
I checked the 3V3 standby voltage regulator and that is good too, so it's beginning to look like the display event processor has died because it isn't responding to it's input despite all the correct signals/voltages being present. I checked all the electrolytic caps on the display board and reflowed the processor to eliminate bad joints but still nothing.
This processor has on board RAM and ROM with model/location specific firmware programmed at the factory, so it can't easily be replaced. I confirmed my diagnosis by plugging in a complete front panel from a LX86. This powered it up but stuck at POWER ON, presumably because the display firmware didn't match the main CPU model.
Does anyone have a solution to this other than a complete replacement display board? I can probably buy a replacement blank processor but without the Pioneer model specific firmware for it the unit still won't work.
This one is starting to look like a doorstopper or for the parts bin unless there is some other way, which is a shame because its in nice condition otherwise.
After a few basic checks, fuses, main power relay, standby +5V, which are all good, I traced the +5V standby to the front panel and checked the power switch itself was good and the clock signal at the display processor was present too. Pressing the power button should result in ACRY and DVCPOW at CN7902 going from low to high but neither change state.
I checked the 3V3 standby voltage regulator and that is good too, so it's beginning to look like the display event processor has died because it isn't responding to it's input despite all the correct signals/voltages being present. I checked all the electrolytic caps on the display board and reflowed the processor to eliminate bad joints but still nothing.
This processor has on board RAM and ROM with model/location specific firmware programmed at the factory, so it can't easily be replaced. I confirmed my diagnosis by plugging in a complete front panel from a LX86. This powered it up but stuck at POWER ON, presumably because the display firmware didn't match the main CPU model.
Does anyone have a solution to this other than a complete replacement display board? I can probably buy a replacement blank processor but without the Pioneer model specific firmware for it the unit still won't work.
This one is starting to look like a doorstopper or for the parts bin unless there is some other way, which is a shame because its in nice condition otherwise.
