Dolby CP650 device won't turn on

[Serhat Gok]

Hello, Dolby CP650 device does not turn on. It goes from P1 to P2. What is the source of the problem?

[Steve Guttag]

P1/P2 are active even on the backup power supply. The Power Button really is a primary power button and has no effect on backup power. So, in a sense, the way to go into backup/bypass was to turn the CP650 off. I'd say that quite probably your main supply has a bad power rail and the unit can no longer boot up. It is also power that the main board has issues and cannot boot up.

[Jim Cassedy]

I think the first thing I would do is to check for presence of all the power supply voltages.
If you remove the front panel of the CP-650, there are six test points for checking the
power supply. (3 terminals are for checking the main PS, & 3 are for t he back-up PS.)
I don't recall what the voltages are supposed to be, but the are stenciled on the circuit
board near the test points.

I had two CP-650's that started acting funny a couple of yeasr ago. Both of them came
back to life & never had any other problems after I re-seated all the cables & boards.
One of those 650's had recently been moved, so I wasn't surprised that some componants
needed re-seating. But the other one had just been siting in the rack and used almost daily
and started suddenly acting 'dead'.. But re-seating everything helped in my case. But, as
I said above, the first thing you should do is check the output voltages.

[Leo Enticknap]

Agreed completely. If the voltages check out, take off the top cover, then the faceplate (single screw holding it onto the front cover), the front cover, the ribbon cables to the display/button panel board, and then remove the cards and boards from the backplane, starting from the top and working down. Take notes as to what goes back on what side, and be careful not to lose standoffs and screws. Also, some of the screws have countersunk heads, and others pan heads: be careful to be able to know what goes back where (though it's pretty obvious). Blast the living crap out of the empty chassis with a DataVac, spray each pin contact assembly with a liberal dose of DeOxit, wipe off the excess with a piece of kitchen roll, and then reassemble, power up, and cross your fingers. If that doesn't resuscitate it, then I'm afraid that the problem is not as easy as a bad power supply or heat cycling working contacts loose over time.

[Sam Chavez]

650's don't really have any strange failure modes that come to mind. Power supply is almost always the problem. There is also the occasional flash memory (Cat. 797?) issue when the 650 can't/won't boot.

[Don Furr]

After going through hell with my 650, I'll keep my 500 in the rack. No more 650's for me.

[Mark Gulbrandsen]

The ONLY issue with 650's I ever had was the power supply. And while I worked at Claco we sold lots of them. Not all of them died, but all with a certain batch of power supplies that had capacators made during the Cap Plague did. You can either replace it, or rebuild it as I did to most of the power supplies.

[Leo Enticknap]

I don't know if Sam still has any in stock, but when that supply runs out (if it hasn't already), rebuilding will be the only option. Same deal for CP750 power supplies, but I given that the motherboards tend to succumb to level drop disease before the power supplies die (unless the unit is being operated in a pretty cool room), most 750s will likely be replaced rather than repaired when that happens. Most of the CP750 power supply failures I've seen are in units that have already had a mobo replacement.

[Sam Chavez]

Since someone mentioned my name, I do still have some CP650 stock. Most brand new circuit boards, but since they don't tend to fail, they don't seem to going anywhere. Im running out of Cat. 790, and Cat. 776 power supplies.

[Steve Guttag]

Same deal for CP750 power supplies, but I given that the motherboards tend to succumb to level drop disease before the power supplies die (unless the unit is being operated in a pretty cool room), most 750s will likely be replaced rather than repaired when that happens. Most of the CP750 power supply failures I've seen are in units that have already had a mobo replacement.

Our CP750 MB to power supply failure is completely the opposite. I'd say that 10:1 (power supplies fail versus motherboards). We always left a space above and below for the CP750 (or any cinema processor). We've seen puckered capacitors on the power supplies...change them and you're back up and going. That said, since the CP750 MB is no longer available, we are advising our customers to plan on failure by preemptively changing at least one out per complex so the complex has a spare on site.

As to the CP650, I have no qualms using it for the "film processor" in a film/digital system. Then again, I have no problem using a CP65/DA20 either. I'm surprised that Don has found that the CP500 to seem more reliable. It too had power supply issues. It also had motherboard issues and timing issues on J14. The front panel display can also cause a lot of grief. I don't know of many techs if there was a CP500 and a CP650 available for a new film installation would pick the CP500 as their first choice.

[Mark Gulbrandsen]

I have only had one power supply fail in a very old JSD-80. None in JSD-60 or 100's. The older JS stuff was also pretty reliable electronically, except the DC Backup P.S. switch of course... But most of those just got bypassed. I think that backup switch was also deleted on later JS Series processors.

[Stefan Scholz]

The ONLY issue with 650's I ever had was the power supply. And while I worked at Claco we sold lots of them. Not all of them died, but all with a certain batch of power supplies that had capacators made during the Cap Plague did. You can either replace it, or rebuild it as I did to most of the power supplies.

Most failures I encountered were PS related. Yes, one can replace capacitor, but they're so cramped in, I gave up. NEW powerr supplies in the 3 x 5 in open frame type are quite reasonable in lower 2 digit numbers. So for me, bought new Mean Well supplies, fitted them, and the 650s worked again.

[Mark Gulbrandsen]

Most failures I encountered were PS related. Yes, one can replace capacitor, but they're so cramped in, I gave up. NEW powerr supplies in the 3 x 5 in open frame type are quite reasonable in lower 2 digit numbers. So for me, bought new Mean Well supplies, fitted them, and the 650s worked again.

I don't think at the time I had to repair - replace them that there was an off the shelf unit available. You only need replace the caps on the DC side of the board anyway. The glue makes it more difficult because you have to spend time cutting it apart with an Exacto knife. But once the goop is cut apart it's pretty easy. I carried kits of 105C caps with me till they were all weeded out.

[Mark Gulbrandsen]

Any caps that are swollen or with obvious leaks indicates a bad power supply board. Get a new one or rebuild the existing if you have the ability to do so. You can also see the nasty glue used to keep the caps from moving around during shipment...

The exact same thing happened to DTS Generation 1 XD-10's. The ones that used the A-Open motherboard. Those are very easy to replace.

[Allan Barnes]

Button gone bad...soft.... I have had that happen.