The elusive Indextron

[jhalphen]

Hi to All,
Hi Mbates14,

Yes, the ARF software was updated at the end of 2022 and now requires some sort of location (can be vague if you want to).

to re-validate your previous account, instructions:

"Send an email to alan AT antiqueradios DOT com and include your username with your message.

I try to respond promptly from 8 am up to 10:30 pm Philippine Time (US Eastern Time + 12 hours)."
(site owner lives there).

Hope this helps,

Best Regards
jhalphen
Paris/France

[dinorhino]

Hi guys! I have been lurking on this forum for years but I finally joined just to post on this thread.

I recently picked up a Sony XAV-u50 with diversity unit from Japan through Buyee, no cables included. Of course shortly after I bought it a complete kit came up for sale but it was a bit to pricey at around $250 + shipping international.

I'm coming here to ask if anyone could share some information on getting these up and running. I plan on making a ribbon style MDR cable for testing (same type as you find in old PCs) because it ends up being cheaper that way, although I'm concerned about how much current that flat ribbon can handle...

I need a way to power the diversity unit, and would like to find the matching connector with all the speaker outputs, if anyone has any info on that like pics of the OEM connector or the pinout, I'd really appreciate it. Finally, should I bother trying to re-cap this thing before I attempt to power it on? I did a visual inspection and there's no signs of leakage on my unit.

Ultimately my plan is to install this in a 90s JDM car and hook up something like a raspberry pi as a way to play old tv shows or even emulate some old games. But for now I just want it working on display in my house.

[HelloVoltage]

Originally Posted by dinorhino

picked up a Sony XAV-u50 with diversity unit

Nice. Congrats.

Originally Posted by dinorhino

a complete kit came up for sale but it was a bit to pricey at around $250 + shipping international.

Didn't see that one come up. Have a link?

Originally Posted by dinorhino

I need a way to power the diversity unit

I used an atx power supply for repair/testing.

Originally Posted by dinorhino

would like to find the matching connector with all the speaker outputs

Originally Posted by dinorhino

should I bother trying to re-cap this

Got 6 diversity units and 8 or 9 of the displays, most xav-u50's. Every one required recaps.

pins 1-4 are 12v+ 14-17 gnd on display board.

There should be 2 void Vias masked as GND and ACC between the fuse and the connector joints. Can solder in wires to provide the power through those just to the display.

[dinorhino]

Thanks so much! I don't have the link unfortunately I recall it sold pretty fast.

I just opened up the one I have and unfortunately it looks like something blew up inside, everything on the right side (around the flyback) is covered in black soot. It smells like nothing. I haven't dug in to inspect yet but I'm already assuming this is gonna have to be a parts unit. When I received it it was filthy, lots of black dirt coming off the outside when I cleaned it. I guess its also possible dust would be attracted to the high voltage components but IDK.
I'll keep my eye out for another I guess. My diversity unit seems just fine, no leaky caps either.
https://drive.google.com/file/d/1tHt...fCYj35mDr/view

[old_tv_nut]

Don't give up until you clean it and look for actual damage.

[dinorhino]

Update: I disassembled the whole thing, gave everything but the tube a generous bath with 99% IPA and a paint brush. Cleaned up really nice, and there is no sign of any blown up components. It must have lived in a really dirty environment.

Upon initial inspection there are no leaky caps surprisingly. There's some differences in my unit from the pics HelloVoltage posted. Board B has conformal coating surrounding the pins on the IC's and capacitors, and I suspect that's hiding some cap leakage, but thankfully it protected the traces.

A few days after washing it I'm starting to smell something fishy (electrolyte) so I will be replacing most of the caps. I tested all of them with my ESR meter and most of them are shot or close to the limit. The giant caps on board D1 are testing as good so I might keep those if they aren't leaking.

Does anyone know if I should bother replacing all the really tiny bipolar electrolytic caps? I don't really know how to identify the value, some just say "10" and some say nothing at all. My ESR meter can't read them either because they are too small, it just shows open circuit. In my experience these never really leak or go bad but I'm curious to what you guys will say.

Last night I made a list of all the caps, minus those tiny ones. I'll post it later once I confirm there's no mistakes.

I'm also gonna pop open the diversity unit again and test all the caps even though they look fine.

I'm always so impressed by the quality and engineering of these early 90s electronics, It seems like it was a time where they had to try really hard to fit things into a small package with mostly through-hole components. The smell of electronics from the late 80s-early 90's is heavenly, its definitely a unique to that time period. The PCBs are usually a much darker green and are always covered in lots of flux.

Next update I'll try powering it on with the new caps.

[jhalphen]

Hi to all,
Hi HelloVoltage,

your assortment of XAV-U50 & diversity receivers is impressive!

Do you have service manuals for both?
Scans? paper? buyable somewhere?
i'm interested in the display unit SM (have one), never tried to use it.

Any photos of your units in operation; would love to see one working (& i bet all Indextron lovers).

@dinorhino : watching your endeavours with interest...

Best Regards
jhalphen
Paris/France

[dinorhino]

Hey guys, another update for ya. I replaced all the bad caps in the main TV unit. Some of the large caps where fine so I left them, and the really tiny 1uf caps because they where fine.

Got it powered on using a 16v 4A laptop charger as I heard these run better with a little more juice, also its all I had that could supply enough amps.

The TV powered on no issues, no smoke. A white raster appeared and then got squished on the edges (see pic). None of the buttons do anything but I expected that being there's no diversity unit hooked up. Slightly concerned about the weird raster distortion, it's exactly like what you can see in this helpful video at 20:45

https://www.youtube.com/watch?v=rrQWaDT61bc

Hoping that with a video signal the distortion will go away.

https://drive.google.com/file/d/1sLY...ew?usp=sharing

[jhalphen]

Hi to all,
Hi Dinorhino,

Congrats! on getting the display unit to show a raster.
How many electrolytics needed changing?
All "normal" Caps (with leads) or some Surface Mounted Devices?

Do you know where to inject Video & which format? (Composite, RGB, VGA...)

I really wish HelloVoltage would help with more tech data, schematics, personal experience, etc.

Best Regards
jhalphen
Paris/France

[dinorhino]

Hi there, I replaced about 60 Capacitors in the tv unit, and around 30 in the diversity unit. All through hole caps.

Today I hooked up my diversity unit to the tv for the first time, I had to figure out the connections for power. There's 2 ground pins, BATTERY, ACC, and REMOTE, all 3 need to receive 12 volts for the unit to power on.

Thankfully the custom cable I made using a old floppy drive ribbon and 26 pin female Centronics connectors was able to handle the current and didn't burn up lol. If you need a cable this is definitely the cheapest and easiest way to do it.

Everything powered up fine, but the screen still shows the same white raster, no menu or anything. When I press the buttons it beeps now so that's a good sign the two units are communicating.

Maybe its not displaying because I haven't hooked up the pins for the "safety harness" that disables the video display when the car is in drive. But I would assume it should still display the menu so you can tune the radio while driving. Ill try that next but I don't know what kind of signal they are expecting.

I would also really appreciate HelloVoltage's input, tell us everything you know please!

If HelloVoltage hasn't already, I intend to reverse engineer the connection between the diversity unit and the tv to see what video signals are being passed. But I need a fully functional unit first.


Update: Something I forgot to mention is that after the white raster gets "squished" half of it turns grey. I discovered that by adjusting the blanking pot on board B the grey part gets brighter or darker. Board B appears to handle the beam indexing and feeds the amplified video to the neck-board and then the cathode on the CRT.

Nothing happened when I tried feeding the B board a video signal into one of its RGB pins either.

I also discovered that by disconnecting the photo sensor board from board B, the pin cushion distortion doesn't happen and the white raster fills the whole screen without changing.

I suspected maybe the diversity unit was not sending video so I tested the connector with my oscilloscope to find what looked like a video signal and I came across one that sort of looked like a video signal and it changed slightly when changing from TV to VIDEO/WM.

Unfortunately while testing I had the tv running for longer than any time before and I heard a small pop and smelled something I can only describe as "too hot electronics" and capacitor juice. So I shut it off and that's as far as I've gotten. I inspected a little and haven't found anything obviously burnt or damaged yet. Checking with a infrared thermometer nothing I can see seems to be getting unreasonably hot, even the vertical output transistor only gets to around 130F

If only there was a service manual available.