Broken MPC 60 - Suggestions?

Hi there,

after years of not using any gear i bought a mpc60.
Said MPC 60 I was sold as "defect", the previous owner didn't use it for years.

As i owned a MPC 3000 some years ago, i figured i might give it a try to solve the problem.

It arrived yesterday, is in good condition... OS 3.10, SCSI, expanded memory and overall looking good.

Previous owner said problem is, after turning the MPC on, nothing is happening. No sign of life...

Here's what i checked: I thought of a powersuplly problem, checked the fuses and connections.
After that, i checked all cables and connections, if anything is loose etc... didn't help at all. As far as i could tell, power is not the problem...

All units inside are looking good, looked like the MPC was handled well over the years...

When i turn it on, the REC light (red) is continously on. The screen isnt showing anything, but by turning the contrast knob it shows me some pixels, which fade away after seconds...
Besides that i get a huming noise when the MPC is open, looks like its the floppy drive...

Any ideas what i could check further? Or some common things that happen often to MPC, which are not used over a long time?

Thanks allready,

Marc



Any help is appreciated

I suggest disconnecting every non vital expansion (floppy drive, ram, etc) and powering it up to see if that helps. maybe a connection came loose over the years.

the screen itself could just be out

FrankieMonroe wrote:the screen itself could just be out

i thought that but would that make the record button stay lit up? that is some sort of indication i would say...

Thank you both for the input.
I tried to disconnect the floppy, ram, scsi board, backlight (alltogether and one at a time) and switched the power on.
No success, but atleast the floppy drive is now "working" (making a noise that sounds like a "ready to use" floppy drive)...
The other sound i mentioned was/is the inverter, sounds pretty "normal"...

The screen is definetly working, shows nothing then some pixel if i move the contrast kno from minimum to maximum a vice versa, though...

As the MPC doesnt boot up, it seems there is some part in the chain missing/not connected properly...?
I will detach everything tommorow and put it back in, with some focus on all connections between the parts...

Record button light staying lit up is weird to me... OS chip problem?

Makeh wrote:Thank you both for the input.
I tried to disconnect the floppy, ram, scsi board, backlight (alltogether and one at a time) and switched the power on.
No success, but atleast the floppy drive is now "working" (making a noise that sounds like a "ready to use" floppy drive)...
The other sound i mentioned was/is the inverter, sounds pretty "normal"...

The screen is definetly working, shows nothing then some pixel if i move the contrast kno from minimum to maximum a vice versa, though...

As the MPC doesnt boot up, it seems there is some part in the chain missing/not connected properly...?
I will detach everything tommorow and put it back in, with some focus on all connections between the parts...

Record button light staying lit up is weird to me... OS chip problem?

well I thought maybe it could mean something or be a characteristic of a problem.

I dont know though, I suggest downloading the service manual to see if it says anything.

there is a thread around here that has links to all the service manuals (minus the 5000 manual I believe)

I would try to get a hold of some OS chips and swap those out since it is easy to do. If you have access to a chip burner I think I have some old OS images you could burn. If that isn't it you will have o start looking at memory, clock, processor etc.

OI got some 3.1 roms

So, i replaced the 3.10 chips with the "old" 1.12 ones- no result.
Besides the possibility that both chip sets could be faulty, i think the problem is somewhere else...

I will read through the service manual now (found it in a thread here, thanks).
Plus, i will take everyything out, check for bad parts on the boards or loose/faulty connections and put everything back in... hope i will get some results.
In my Mpc 3000 i had a similar problem, after i cleaned it up and accidently changed two connectors... all lights were on the whole time and no sign of life on the screen...
But in my MPC 60 everything seem at the right place.

I'd be curious if it wasn't a residue issue. Make sure to look for white calcium residue on the boards and around components

Makeh wrote:The screen is definetly working, shows nothing then some pixel if i move the contrast kno from minimum to maximum a vice versa, though...

I had exactly this problem when i had my OS chips were, strange that it didnt work out for you with new chips. I would check every connector between the power supply and the main board. Maybe the chips isnt getting any power.

All boards and parts seem fine, nothing unormal.

After putting everything back in, the same problem occurs: The screen turn on for a second (not really bright, though), but only some weird pixels that fade away. The record light is lit on, the floppy drive "working". Putting in a floppy and try do load, save etc. did nothing... no response from any of the pads or buttons.

The i took the cable which powers the screen (the one from the inverter) out and powerd it on again - after that the record AND the overdub light was on!
I checked the output of the inverter and metered around 18v, which is not ennough to power up the screens backlight, i guess?

I think there is something wrong with the overall power, seems there is not enough power to bring the main board etc. to life... will check and meter every connection from and to the power supply.

@mikaei: both chip sets could be faulty, but at the moment i think the problem is somewhere else... did you just replace the OS chips and everything worked?
i don't want to buy the OS 3.10 "again" ... haha

I can multimeter my inverter to get you operating specs.

That would be highly appreciated!

And if you got that thing open, could you please meter the specs from the connections of the main power supply to the mainboard? This way i could easily tell if there is any power going to the OS chips...

Makeh wrote:@mikaei: both chip sets could be faulty, but at the moment i think the problem is somewhere else... did you just replace the OS chips and everything worked?
i don't want to buy the OS 3.10 "again" ... haha

A long time ago i came over eproms that "could" be the 3.10 OS, put them in, got exactly the same error as you. Tried putting them in backwards etc. never worked. Put in my old 2.12 and everything worked.

I think there is something in the tech manual about starting up the up MPC60 in testmode, maybe you could try that just to see if the display comes on. I don't have the manual on this computer but it's around, pretty sure it's at the mpc60 yahoo group at least.