Boss BR-1180 No Power on

[ca7922303]

I think you are checking pin3, we need to know pin1.

Sorry bout that,
Q33 pin1(0.0mv) pushing momentary power on button (0.0mv).

[g1]

Sorry bout that,
Q33 pin1(0.0mv) pushing momentary power on button (0.0mv).

Do a diode or resistance check between pins 1 and 2 of Q33.

[ca7922303]

Do a diode or resistance check between pins 1 and 2 of Q33.

Diode test between Q33 pin1/pin2(0.45v).

[g1]

Sorry bout that,
Q33 pin1(0.0mv) pushing momentary power on button (0.0mv).

You should check this again. If there was nothing at all happening, the voltage would not have moved at Q31 pin 2 (post #14).
Looking for around 0.5V at Q33 pin 1. Or any kind of voltage change when pushing power button.

[ca7922303]

You should check this again. If there was nothing at all happening, the voltage would not have moved at Q31 pin 2 (post #14).
Looking for around 0.5V at Q33 pin 1. Or any kind of voltage change when pushing power button.

Ok, I didn't notice this before but Q33 pin1 starts at (+0.0mv) and changes to (-0.0mv) when power button is pushed, then back to (+0.0mv). Tried it several times to be sure.

[g1]

Sounds like the CPU is not sending Q33 it's command.
Double check at CPU (IC28) pin 35. Be very careful not to short any pins together with your meter probe. If they are too close together, try checking at both sides of R147 instead.

[ca7922303]

Sounds like the CPU is not sending Q33 it's command.
Double check at CPU (IC28) pin 35. Be very careful not to short any pins together with your meter probe. If they are too close together, try checking at both sides of R147 instead.

I'm able to get (0.0mv) to mostly around (200-300mv) power button pushed. But maybe every 6-8 or so pushes of button I get around (1.5v). It's about the same on both sides of R147. IC28 pins are way too close for me to measure. Hand not that steady. Also R147 measures(1K ohms) in circuit.

[g1]

At this point it's getting a bit out of my league as the CPU circuitry is fairly complex. You could check that the CPU is getting all it's supply voltages and clock signals but beyond that I don't know.
For myself, I would probably try jumpering pins 2 to 3 of Q33 to see if the unit is capable of running.

[ca7922303]

At this point it's getting a bit out of my league as the CPU circuitry is fairly complex. You could check that the CPU is getting all it's supply voltages and clock signals but beyond that I don't know.
For myself, I would probably try jumpering pins 2 to 3 of Q33 to see if the unit is capable of running.

I appreciate all your help as always. I'll try jumping Q33 pin 2 to pin 3 shortly and let you know. Thanks.

[ca7922303]

At this point it's getting a bit out of my league as the CPU circuitry is fairly complex. You could check that the CPU is getting all it's supply voltages and clock signals but beyond that I don't know.
For myself, I would probably try jumpering pins 2 to 3 of Q33 to see if the unit is capable of running.

Jumped Q33 pin2 to pin3, now getting about (325mv) and blinks when button is pushed but doesn't really go up except after about 8-10 pushed I see a (1.5v) momentarily. Unit now does not have lights or screen blink on. It has a Seagate Barracuda hard drive, maybe I'll use it on a computer if it's still any good?

[g1]

If you are going to scrap it, the drive would probably work for a computer.
Otherwise, you could have a Roland repair center look at it, but I'm not sure it's value and what it would be worth to spend repairing.

[ca7922303]

If you are going to scrap it, the drive would probably work for a computer.
Otherwise, you could have a Roland repair center look at it, but I'm not sure it's value and what it would be worth to spend repairing.

Looks like reverb has a couple @ $200.00, so I imagine it will cost more than it's worth if have boss authorized repair done. Maybe I find a complete used board for it one day on ebay?

[g1]

Looks like reverb has a couple @ $200.00, so I imagine it will cost more than it's worth if have boss authorized repair done. Maybe I find a complete used board for it one day on ebay?

Maybe. Or maybe a cheap broken unit that you could try swapping the CPU, assuming it's in a socket.