View Full Version : Sony KP-7220 Tragedy


MIPS
06-19-2017, 10:58 PM
Oh man, I didn't want to make this thread. I'm sorry. :tears:

This was seen on the Bellingham Craigslist last month for $60, sold as "working".
No remote or top glass but came with the base projection unit and the massive 72" silver screen with a few small nicks and bruises but still in great shape.
I managed to persuade a friend in the Everett area to pay and pick it up for me and hold onto it until I could collect it this past weekend. When I arrived he had already unbolted the legs from the screen and everything was waiting in the garage. The projection unit was loaded in the car and after verifying that the screen wouldn't scratch or mar up by being handled it was carefully wrapped in a tarp and strapped to the roof with the screen facing down.

http://i11.photobucket.com/albums/a166/ballsandy/New%20Bucket/CGS_0830.jpg

The drive was relatively uneventful and the screen didn't make any attempts to make an escape from the roof rack. Unloaded it all late last night and this afternoon managed to unwrap the screen and better look over the projector.

Son of a.....

http://i11.photobucket.com/albums/a166/ballsandy/New%20Bucket/CGS_7617.jpg
http://i11.photobucket.com/albums/a166/ballsandy/New%20Bucket/CGS_7618.jpg

The silver coating is ruined! The tarp must of been way more abrasive than I expected it to be and simply wrecked the reflective surface. I knew I should of padded the face with sheets of foam before wrapping it up. No gouges however but no idea how to resurface that. :nono:

http://i11.photobucket.com/albums/a166/ballsandy/New%20Bucket/CGS_7619.jpg
http://i11.photobucket.com/albums/a166/ballsandy/New%20Bucket/CGS_7620.jpg

The projector from the outside showed signs of wear (and the above missing components) but all I was going to do was put my Pioneer VP-1000 on top and call it good so that was fine. Inside there was a little bit of dust but everything seemed okay.
Plugged it in and pushed the power button. Heard the high voltage come up, audio came up and saw red and green but the blue was stone dead. Was not able to see if the filament was lit because as I reached to toggle the NORMAL/TEST switch a small lytic cap on the rear board of the red gun puked its guts and I killed the power.
Add insult to injury I seem to of misplaced the four bolts that you used to attach the screen to the stand, so nothing in the set right now actually "works". Additionally, this is another one of those products where it seems you can find the service manual online in PDF form, but you gotta pay to download it. My usual sources of manuals do not seem to have it either. 1200km for another project. :sigh:

Here's a photo of what the set and (smaller model) screen looked like when it WAS all together and working.


http://i11.photobucket.com/albums/a166/ballsandy/New%20Bucket/kp5020pse_1982top_171.jpg

Electronic M
06-20-2017, 09:32 AM
Way too late for this advice I know, but: A favorite packing material of mine is 4'x8'( x2" or x3/4") sheets of Styrofoam insulation from the local hardware stores....If you cut one slightly bigger than the screen set it face down on it and taped the sides of the screen frame to the foam the screen likely would have fared better.

When I was a wee lad one a my kin had such a beast in their basement rec room, can't remember the make or model, but I thought it was more interesting than the stuff they were watching on it. :D

Best of luck getting it working.

andy
06-20-2017, 12:00 PM
The rule with these silver screens it that nothing should ever touch it. Even cleaning them is best avoided except when absolutely necessary. The surface has a fine texture which is essential. I'm not sure how you would be able to resurface it, but I'd love to find a way since they almost always have some scratches.

I have a PDF of the service manual if you still haven't found it.

I have a KP-5020 which is mostly just used as a table, but I do bring out the screen sometimes for parties/holidays.

It's not a bad set, but it's severely handicapped by the lack of a video input. It has a hot chassis, so adding one isn't straightforward. There's actually a spot on one of the boards for an A/V input (complete with optoisolators), but it would be a big project to figure out all the component values. Maybe there was a Japanese version with the input?

I did add a digital comb filter module from an old Sony 32" TV chassis to improve the picture resolution and reduce false color.

rpm1200
06-20-2017, 01:23 PM
Since you have nothing to lose at this point, maybe you can try repainting the screen using the silver paint that is designed for creating screens on walls. I assume the two issues there would be getting the surface as smooth as possible, and ensuring that the paint would adhere to the screen.

I'm sure you will be able to get the electronics fixed up and replace the missing hardware.

centralradio
06-20-2017, 03:23 PM
Nice catch.I have a curved screen here from a Sears set which was destroyed from moving around place to place.Your base unit looks clean.Probably just beam it on to a white wall for now.The big tragedy with those sets are CRT burn ins.

If you dont have it yet. Heres the free service manual for your set from freeservicemanuals.info .Looks like this manual is for worldwide multi broadcast format set.

https://freeservicemanuals.info/en/servicemanuals/viewmanual/Sony/KP5020PSE/KP7220PSE/

TVTim
06-21-2017, 07:34 PM
How about an old movie screen? I see them on Craigslist from time to time.

MIPS
06-22-2017, 09:55 AM
Those are all fabric based. This screen is a giant sheet of molded plastic with a metal film adhered over it.

If you dont have it yet. Heres the free service manual for your set from freeservicemanuals.info .Looks like this manual is for worldwide multi broadcast format set.
I'm looking at that page with my ad blocker on and off and I cannot see the actual download link.

andy
06-22-2017, 01:59 PM
Getting it to converge and focus on a flat screen would be difficult. The dynamic convergence controls might not have enough range. Also, they depend on the ultra high gain of the curved screen to be bright enough.

These types of screens used to be common, so one might turn up eventually. If you find one that's a different size, you can readjust it to work. The lenses do have focus adjustments, and you can change the angle of the red and blue CRTs by installing spacers. I briefly had my 5020 projecting onto an 80" Advent screen until I bought an NEC data grade projector that can do HD.

centralradio
06-22-2017, 07:01 PM
How about an old movie screen? I see them on Craigslist from time to time.

I was thinking the same thing.

Those are all fabric based. This screen is a giant sheet of molded plastic with a metal film adhered over it.


I'm looking at that page with my ad blocker on and off and I cannot see the actual download link.

With Firefox with cookies off and ABP on.Its OK.

Where it says.

Brand Sony
Type a KP-5020PSE "click here".

MIPS
06-22-2017, 09:26 PM
Ah, there it was. It was hiding on me.
Okay I'll take a few days to skim over the book and work from there. Until the set works I'm sidelining the screen.