C258 no power

[copyman]

Going out to this call tomorrow and check voltages on pwr supply. Had customer confirmed over phone outlet is live, main sw on, etc.
No lights, fans or motors. It's on a good surge protector.

Has anyone replaced a pwr supply on the "8" series? Machine is far away and if I get feedback from you guys that these pwr sup do go bad than I'll get one before driving that far.

I'll probably regret saying this but I've never had to replace a pwr supply on the "4" or "8" series and have around 100 of these models I service.
I know there is always a first but still think I would have replaced at least one over the years.

Printed out some bulletins, solutions, etc from K/M website addressing no pwr issue.

Thanks in advance for the help.

[tsbservice]

Re: C258 no power

As far I know there are not known issues with PS on this model. Few things to check:
1. Check the power supply
2. When the on board DIMM and Option DIMM if it is installed, disconnect it and check if the machine boots up.
3. Check the connector between MFPB- Operation Panel

[copyman]

Re: C258 no power

As far I know there are not known issues with PS on this model. Few things to check:
1. Check the power supply
2. When the on board DIMM and Option DIMM if it is installed, disconnect it and check if the machine boots up.
3. Check the connector between MFPB- Operation Panel

Thanks tsbservice one of the bulletins mention the DIMM, that will be first thing I try if 115 vac, 24 vdc & 5 vdc voltages are all good.

Kinda glad to hear power sup going bad is not a common problem

Will report back with what I find.

[copyman]

Re: C258 no power

Update: Ended up taking the power supply out of a C308 parts machine I forgot I had to bring with me. Before removing from parts machine took all the power supply readings and made note of them before removing, 115AC coming into board and 5vdc & 24vdc present all the time.

Went to customers office and checked their pwr sup, no 24vdc. Ok simple swap pwr sup. Guess what, no 24vdc on pwr sup I brought with me!
Put their pwr sup back in and tried several things from bulletins and suggested here, removing DIMM, disconnecting HDD, Fax, etc etc.
Nothing worked still dead.

Took my original board back to shop and powered right on with no problem, 24vdc present all the time.

Really weird that the 24vdc isn't present on both boards. Doesn't make sense. I'm guessing there is something that triggers pwr sup 24vdc signal to turn on? I'll have to take a look at the schematics.

Machine has less than 50k clicks.

Any ideas appreciated?

Thanks for any help

[BillyCarpenter]

Re: C258 no power

Update: Ended up taking the power supply out of a C308 parts machine I forgot I had to bring with me. Before removing from parts machine took all the power supply readings and made note of them before removing, 115AC coming into board and 5vdc & 24vdc present all the time.

Went to customers office and checked their pwr sup, no 24vdc. Ok simple swap pwr sup. Guess what, no 24vdc on pwr sup I brought with me!
Put their pwr sup back in and tried several things from bulletins and suggested here, removing DIMM, disconnecting HDD, Fax, etc etc.
Nothing worked still dead.

Took my original board back to shop and powered right on with no problem, 24vdc present all the time.

Really weird that the 24vdc isn't present on both boards. Doesn't make sense. I'm guessing there is something that triggers pwr sup 24vdc signal to turn on? I'll have to take a look at the schematics.

Machine has less than 50k clicks.

Any ideas appreciated?

Thanks for any help

I think you're on the right track but I would ohm out the 24vdc from the board to ground just to make sure it's not shorted. This machine could have a fail-safe if it detects a short circuit and it would shut down quickly.

[tsbservice]

Re: C258 no power

Update: Ended up taking the power supply out of a C308 parts machine I forgot I had to bring with me. Before removing from parts machine took all the power supply readings and made note of them before removing, 115AC coming into board and 5vdc & 24vdc present all the time.

Went to customers office and checked their pwr sup, no 24vdc. Ok simple swap pwr sup. Guess what, no 24vdc on pwr sup I brought with me!
Put their pwr sup back in and tried several things from bulletins and suggested here, removing DIMM, disconnecting HDD, Fax, etc etc.
Nothing worked still dead.

Took my original board back to shop and powered right on with no problem, 24vdc present all the time.

Really weird that the 24vdc isn't present on both boards. Doesn't make sense. I'm guessing there is something that triggers pwr sup 24vdc signal to turn on? I'll have to take a look at the schematics.

Machine has less than 50k clicks.

Any ideas appreciated?

Thanks for any help

I think you will need MFPB then. Bad luck.
Recently Blackcat described in one thread(I forgot which one) how these things work. Basically PS supply 5Vs to MFPB and upon send back signal from MFPB supply another voltages to the rest of machine.

[copyman]

Re: C258 no power

I think you will need MFPB then. Bad luck.
Recently Blackcat described in one thread(I forgot which one) how these things work. Basically PS supply 5Vs to MFPB and upon send back signal from MFPB supply another voltages to the rest of machine.

Good call tsb. The MFPB sends the signal to turn on 24vdc during boot sequence.

Another indicator MFP board is bad is if no blinking light on MFP.

Going to send MFP board in for repair.

Thanks

[tsbservice]

Re: C258 no power

Good call tsb. The MFPB sends the signal to turn on 24vdc during boot sequence.

Another indicator MFP board is bad is if no blinking light on MFP.

Going to send MFP board in for repair.

Thanks

NP copyman, just want to backup one of the fellow techs here. I always try to walk in a shoes of tech who deserves his pay working his as*... like I do.