Film-Tech Forum ARCHIVE: Cat 150 Card Problem

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Posted by Jeremy Weigel (Member # 4208) on 08-22-2009, 11:30 PM:

I have a bad Cat 150(F) card in a CP65 that is producing very low non-sync, LCR in SR, and popping sounds in the surrounds. Does anyone know if Dolby still does repair/exchange on these?

Posted by Pete Naples (Member # 761) on 08-23-2009, 06:19 AM:

No they do not.

Only option from Dolby is a new one, which they will only offer a 90 day warranty on.

Posted by Louis Bornwasser (Member # 3063) on 08-23-2009, 06:45 AM:

You might look at the solder connections on the crystal (shiny oblng can). Because of its location near the front, it is easily bumped. Similar symptoms. Louis

Posted by Steve Guttag (Member # 268) on 08-23-2009, 08:52 AM:

Do you mean it plays the movie fine but not Non-Sync? The Cat 150 doesn't know it is getting Non-Sync versus the film sound...if that IS the case...your problem is further upstream (Cat 242 or possibly the Cat 443 is not configuring things right).

Posted by Jeremy Weigel (Member # 4208) on 08-23-2009, 12:38 PM:

quote: Steve Guttag
Do you mean it plays the movie fine but not Non-Sync?

Non-sync level very low(actually noticed this a few days ago, but chalked it to someone messing with the levels coming off the Smart DA220). During playback in SR the LCR channels are very low in level and there are popping sounds coming from the surrounds only. It all sounds fine in SRD, which is probably why till now we hadn't noticed the problem in SR.

I have already narrowed it down to the 150 card by swapping cards with another CP65. Put the good card in and voila non-sync level came back up and SR worked great.

Also, with the defective card in place and the CP65 in BYPASS, audio sounds fine (of course no non-sync and surrounds; only L&R output I believe). And for what its worth we have non-sync set for 2:4 mode which might explain the level drop since the 150 card has the Pro-Logic chip on it.

quote: Louis Bornwasser
You might look at the solder connections on the crystal (shiny oblng can). Because of its location near the front, it is easily bumped. Similar symptoms.

Thanks Louis, I'll check it, although I don't recall seeing that on the 150F card(defective) vs the 150E card that I swapped it with.

I do recall the E version having a green ob-longed shaped component on it. I also noticed that the E version has 4 rectifiers that mount into sockets, whereas the F version has only 3 rectifiers that are soldered directly to the board. Were these rectifiers known to go bad on the E version, hence why they put them in sockets?

Posted by Jeremy Weigel (Member # 4208) on 08-26-2009, 09:17 PM:

OK. Dolby will do repair/exchange on a 150E, but not the 150F card. [Frown]

Anyway,

I did test my hypothesis regarding the 2:4 non-sync and it does turn out that if I put non-sync in std mode it sounds fine, but SR still sounds awful. I did check the silver (flask shaped w/ wire strap) solder connections, but they were fine.

For now I have swapped cards with a CP65 stacked with a SDDS unit and put the CP65 in BYPASS in case the SDDS track fails in spots so that at least there is some form of analog fall-back. I can get a new card from Dolby for about $650, but I will keep browsing eBay or hopefully someone on here has an extra they'd like to sell at a reasonable price.

Posted by Gordon McLeod (Member # 33) on 08-26-2009, 11:21 PM:

Some of the analogue devices chips on the 150f are no longer made by the chip manufacturer

Posted by Steve Guttag (Member # 268) on 08-26-2009, 11:32 PM:

The main chip on the Cat 150F is NLA...but so is the Sanyo chip on the Cat 150E. The key here is that the Cat 150E is used in the SDU4 as well and that is why it is still a serviceable part. The 150F was strictly cinema.

Note, 9 times out of 10, one of the flame proof resistors on the power regulators has opened and you have lost a power rail.

Steve

Posted by Jeremy Weigel (Member # 4208) on 08-29-2009, 10:39 PM:

Are the flame-proof resistors the ones with the small ceramic(?) rings around each leg (R1,R7,& R4)? And to test any resistor, I will need to de-solder one side from the board, correct?

Posted by Tony Bandiera Jr (Member # 2365) on 08-30-2009, 08:35 PM:

Jeremy:

Yes and yes.

A good electronic store should have the replacement resistors in stock.

Posted by Jeremy Weigel (Member # 4208) on 08-30-2009, 10:48 PM:

Thanks Tony. I get a reading of 2.4 Ohms on all 3, which if I'm seeing the color of the bands correct (Red, Red, Gold, Gold) it is with in tolerance.

My other thought is that maybe one of the voltage regulators might be bad. I've looked them up on mouser.com, but I'm not sure which would be the correct ones for the 2 LM317T's and LM337T. You guys have any thoughts?