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Chromedome45
May 26th, 2011, 06:35 PM
My Sony Multisync CP-1302 is slowly dieing and was wondering if there are any monitor repair types out there. Or who can recommended a reputable monitor repair service.
Please advise. ;)

Chuck(G)
May 26th, 2011, 06:40 PM
Believe it or now, I think I may have the service manual for the thing. I'll look this weekend, if you'd like.

Great monitors for their time.

But like most Sony gear of the time, crappy power supply design.

Chromedome45
May 27th, 2011, 06:23 AM
Thanks Chuck would be appreciated.

RetroHacker_
May 27th, 2011, 06:44 AM
I repair monitors.

You don't mention what's wrong with it though - what do you mean by "slowly dying"? Is it getting dim, not wanting to turn on, smearing colors, losing sync, etc?

-Ian

Chromedome45
May 27th, 2011, 08:11 AM
Well For the longest time it would not work with an analog input (VGA) well last night I decided to try one more time to see if I can get an analog signal to work. Well to my surprise it did work. Had it hooked up to my IBM 50z and had it running for about an hour. Then I decided to make sure the Digital was working well it was but anything using graphics would blank the screen. Tried turning off then on and I would see graphics for a few seconds than would go away. Hooked up an analog signal again and it too was not working now. Not sure what has happened but I noticed the power LED was getting dimmer. So I think what has happened is the power supply by dropping voltages may be causing the Monitor to loose sync. But I am just guessing here. It does try to turn on though just doesn't seem to have enough voltages to kick everything in gear. Colors were fine when last working. Not sure if this helps explain the problem but if you could RetroHacker_ send me a PM as to an estimate to repair. I would really like to get this thing working again. BTW there is a switch on the back to allow changing from Analog to digital.

Chromedome45
May 27th, 2011, 11:21 AM
Definately a power supply issue the Low voltage distribution PS has low outputs 80v is 23v 15v is more like 4v etc. The input power supply which sends 300v to the distribution PS is good though. 300v output. But without a schematic it's hard to figure which voltages go where.

RetroHacker_
May 27th, 2011, 11:25 AM
Definately a power supply issue the Low voltage distribution PS has low outputs 80v is 23v 15v is more like 4v etc. The input power supply which sends 300v to the distribution PS is good though. 300v output. But without a schematic it's hard to figure which voltages go where.

I'd suggest replacing capacitors in the power supply section, especially the ones close to the heat sinks. They just sit there and get cooked from the heat. I find lots and lots of bad capacitors in monitors - it's a good place to start looking.

-Ian

Chromedome45
June 3rd, 2011, 02:10 PM
Replaced caps and still no go. I'm starting to think the 2 big switching transistors 2SC3318's are weak. everything else looks good using an DMM.
Diodes, Transistors etc. But there is one item on there that is worrying me. It's reference is IC501 its a black coated 9 pin device which looks like it has a couple of diodes and transistors in it. Maybe a regulator of sorts I don't know. And thre is also an SCR but ohming it looks good. I'll keep hacking away at it. Unless Mr RetroHacker_ wants a shot at it??

Chuck(G) did you find a service manual for this Monitor?

Chuck(G)
June 3rd, 2011, 04:01 PM
Missed your original response; @(*#^$ "New Posts" tab keeps dropping responses for me. I'll have a look this weekend. I must have it--I don't throw those things away.

Chuck(G)
June 4th, 2011, 08:44 AM
Found the service manual (and a user manual as well). Unfortunately, it's not scannable--fold out pages would make it pretty awkward. So I'll have t mail it to you--contact me to arrange.

Alternatively, I could scan just those sections that you need or answer questions.

Chuck(G)
June 9th, 2011, 04:21 PM
Guess you're not interested anymore. Back into the files it goes...

Dr. Hugo
June 9th, 2011, 10:53 PM
Hi,
I have a good working knowledge of CRT video monitors. If you have a problem and have the monitors schematic or can tell me the symptoms I may be able to help.
I have just posted a question on trying to fit a hard drive to an IBM5155. This one uses an amber crt.

Chuck(G)
June 9th, 2011, 11:17 PM
DH, the Sony 1302 Multiscan is a beast of monitor--it uses relays to change the sync rate--and can sync from CGA to VGA display rates; handles both analog and TTL signal levels. A far cry from either a CGA or monochrome monitor

Have you ever worked on a Sony Multiscan? The setup directions use a Sony SMC-70 PC to generate appropriate sync frequencies. Apparently there was a special diagnostic diskette that ran on the SMC-70. I've never run into one.

Chromedome45
June 10th, 2011, 08:06 AM
The problem is in the power supply. Seems as though primary side has low voltages going to secondary through a large Bobbin Transfomer. All transformers ohm good. There are about 5 or 6 of them in there. So I am guessing that the primary switching Transistors are weak. I ordered them and will install and see if it brings it back to life.

Dr. Hugo
June 10th, 2011, 05:19 PM
Hi again, Looks like you are heading on the right track with the monitor repair and replacing the electro's first. The first thing is to get the power supplies at the correct voltages. If you were able to post/attach a scan of just the power supply part of the circuit & switching transistors I could make some recommendations on testing it, and its individual components to help get to the bottom of which component has failed.

Chromedome45
June 16th, 2011, 06:56 AM
My main concern is this little "integrated circuit" that is a custom sony part. it looks like a small circuit board with about 8 components inside but is cover with that black conformal coating. I think it is some kind of regulator circuit. Also there is an SCR I can't seem to find anywhere only some datasheets. Maybe I can get a close substitute. It is a 2amp 400 volt unit. I have seen 4amp 400 volt at jameco for less then a buck might have to try and get it. I will see about scanning the diagrams for you once I get the manual. Or send the Whole monitor to you Hugo if I can't make any headway.

Chromedome45
July 4th, 2011, 06:43 AM
Its now available for price of shipping if anyone wants it. Includes service manual

Chuck(G)
July 4th, 2011, 08:46 AM
I trust that you've scanned the service manual for others. It would be a shame to lose the information.