Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Solid State CRT Televisions

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #31  
Old 08-12-2018, 02:00 AM
Electronic M's Avatar
Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,758
Good news and strange news:

On Friday the box from Encompass arrived. I ordered 3 genuine Sony chips and 2 of the cheap equivalents. The box contained 7(!) genuine sony chips, 1 knockoff, and a plastic button for god knows what in a bag labeled with the correct chip part number. Strange, not exactly what I ordered but you won't hear me complain over getting $100 extra worth of quality parts for free.
DSCN9659 by Tom Carlson, on Flickr
The one knockoff chip I received appears to be a blatant fake according to this video so I don't plan to use it (I have 6 genuine spares to fall back on after all). https://www.youtube.com/watch?v=euDQVrgde4Y That video also shows an interesting way to test these chips...If I still had my spare 30" High-Scan (gave it to a friend when I got the Super-fine-pitch) I'd be tempted to make that into a chip test rig.

This site gives a good walkthrough of the procedure to change the chips with some good tips. http://k0lee.com/2011/05/fixing-a-so...-7-blink-code/ A couple more tips not in link I think are worthwhile: You can do some diagnostic work to tell which chip*, and adding a DIP heatsink to give the replacement(s) a chance to run cooler.

*Looking at the schematic IC6501 provides a number of power supply rail voltages (well the transformer whose driver FETs the IC drives provides the voltages but you get the idea) and IC8002 drives (the FETs that drive) the flyback/HV system. My set had some life: relays clicked ~3 times on power up and the blinking front LEDs (power and Memory Stick port), so those supply rails probably worked, but there was no HV start-up crackle so IC8002 was probably dead. If you have an HV probe that can measure at least 35KV (my set clocks in at ~32KV) you can confirm no HV by measuring the HV as I did.

I replaced IC8002 with a socket that I then filled with a new IC with a heat sink attached. That restored operation, and seems to have improved brightness and edge convergence some.


For now, I'm only replacing IC8002. I don't want to waste a good part by removing the other MCZ from the board, and I want to see how long it lasts.
Also I had been leaving well enough alone till the chip failure to the point that I never tried to reduce the noticeable overscan...Now that I've had to mess with it I'm going to have to fix that too.

Some interesting things I've noted looking at this set: It has a September 2004 build date, and the soldering on the board suggested the chips were original to the board. The dust on the board looked to match the rest of the set so it could be the original sweep board. If that is the case this set lasted 14 years on its original chips (not bad at all from what I've heard). The CRT ID sticker says made in the USA so it would seem Sony had a Trinitron plant here in the USA. The replacement chip had a lower date(?) code than the original (~....200 vs ~....600), which makes me wonder if the replacement parts are older than my set (both were MCZ3001DB). The Memory Stick reader connects to the chassis with a USB cable...That makes me wonder if I could plug a thumb drive in to play video, or connect an SD card reader to the chassis.

Next time I replace a horizontal oscillator I hope the part number is 6SN7 and not MCZ3001DB!
__________________
Tom C.

Zenith: The quality stays in EVEN after the name falls off!
What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
Reply With Quote
  #32  
Old 08-22-2018, 04:31 PM
Electronic M's Avatar
Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,758
Still going strong 10 days later.

user181 filled my last open PM box slot to ask about this so this is my only easy means of reply...
__________________
Tom C.

Zenith: The quality stays in EVEN after the name falls off!
What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
Reply With Quote
  #33  
Old 08-22-2018, 07:33 PM
Dave A's Avatar
Dave A Dave A is offline
VideoKarma Member
 
Join Date: Aug 2003
Location: SE Pennsylvania
Posts: 1,529
I picked up my 970 about 7 years ago and it ran fine for 3 years then the 7 blinks started. Not knowing about the chip and only able to find some more generic tips, I replaced the entire AZ board. STDBY supply. I got the last board in the world and I got lucky. It is still going strong and I have a board to change out in the future. I did check the bdent website from the video and they still list them at $7.95 each and they have the proper markings as original. May try a few. EM...could you do testing via surface mail?

OT on the 970. Does anyone know which service adjustment would get me to curing a right edge bow towards center? I have the manual but not sure which one does the trick.
__________________
“Once you eliminate the impossible...whatever remains, no matter how improbable, must be the truth." Sherlock Holmes.
Reply With Quote
  #34  
Old 08-22-2018, 07:37 PM
user181 user181 is offline
VideoKarma Member
 
Join Date: Nov 2013
Posts: 451
Quote:
Originally Posted by Electronic M View Post
Still going strong 10 days later.

user181 filled my last open PM box slot to ask about this so this is my only easy means of reply...

Oops! I should have checked this thread first. Somehow I missed a notification that it was updated before.

Glad to hear the good news! And the bonus deal you got, to boot! It's always nice to have extra spares.

When you did the board work to replace the chip, did you completely remove the board from the set and take it to the bench, or work on it in-situ?

Also, what type of desoldering tool did you use?

I'm asking all this for future reference.
Reply With Quote
  #35  
Old 08-22-2018, 08:48 PM
etype2's Avatar
etype2 etype2 is offline
VideoKarma Member
 
Join Date: Mar 2010
Location: Valley of the Sun, formerly Silicon Valley, formerly Packer Land.
Posts: 1,487
I have one of these sets. Sometimes a reset will clear the startup problem. It has worked for me.

Turn on the TV. While holding down the RESET button on the remote factory settings control, press the POWER button on the TV. (The TV will turn itself off, then
back on again.) Release the RESET button.
__________________
Personal website dedicated to Vintage Television https://visions4netjournal.com
Reply With Quote
Audiokarma
  #36  
Old 08-22-2018, 11:29 PM
Electronic M's Avatar
Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,758
Quote:
Originally Posted by Dave A View Post
EM...could you do testing via surface mail?
If your set has the same chassis I could probably test a board (if I understand your question). I need to figure out the best way to unplug the wires from the FBT to the neck board though. If you know the right way to remove them I'd be interested in knowing.

To answer other questions as a collector of heavy bulky tube TV consoles, and someone who keeps much of his collection on the second floor, and the rest as well as the workbench in the basement I've learned to bring the tools to the set when it is not as easy to do it the other way around. If I was persistent enough to remove the above-mentioned leads to the neck board I could have done it downstairs, but they were not coming off easy and I decided against forcing things.

I used a vacuum de-solder tool (IIRC it is called the Solda-pult)...The largest size I've seen sold (~12" long)...Normally that tool gets used on tube electronics with larger solder blobs. It was not ideal (I wish I had a smaller one), but repeated heating and vacuum cycles (and a touch of fresh lead solder) did the trick. I did have a 25W iron which is more appropriate for PCB work than the 75W-150W cattle prod irons I normally use on the older stuff.

This for me was an exercise in soldering finesse.
__________________
Tom C.

Zenith: The quality stays in EVEN after the name falls off!
What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
Reply With Quote
  #37  
Old 08-23-2018, 06:54 AM
zeno's Avatar
zeno zeno is offline
VideoKarma Member
 
Join Date: Mar 2013
Location: New Hampshire
Posts: 4,672
FBT wires on late Sonys often need a special tool. They shipped without wires.
Dont remember if they could be removed any other way.

73 Zeno
LFOD !
Reply With Quote
  #38  
Old 08-23-2018, 09:51 AM
user181 user181 is offline
VideoKarma Member
 
Join Date: Nov 2013
Posts: 451
Quote:
Originally Posted by Electronic M View Post



I used a vacuum de-solder tool (IIRC it is called the Solda-pult)...The largest size I've seen sold (~12" long)...Normally that tool gets used on tube electronics with larger solder blobs. It was not ideal (I wish I had a smaller one), but repeated heating and vacuum cycles (and a touch of fresh lead solder) did the trick.
OK. I have a desoldering iron with integral vacuum bulb. Hope that will be appropriate.

When you were working on the board, was it pretty straight-forward to move it up into the service position? I know this is described in the service manual, but it's always nice to have a real-world description of it too.

Quote:
Originally Posted by Electronic M View Post
I did have a 25W iron which is more appropriate for PCB work than the 75W-150W cattle prod irons I normally use on the older stuff.
You usually don't even need to plug in a 150W iron, as the terminals will quiver in fear & heat up on their own if you come near them with an iron that size. ;-)


Quote:
Originally Posted by Electronic M View Post
This for me was an exercise in soldering finesse.

I understand. The good thing about it is that at least these are through-hole ICs, rather than surface mount.
Reply With Quote
  #39  
Old 08-23-2018, 10:40 AM
Electronic M's Avatar
Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,758
Quote:
Originally Posted by user181 View Post
OK. I have a desoldering iron with integral vacuum bulb. Hope that will be appropriate.

When you were working on the board, was it pretty straight-forward to move it up into the service position? I know this is described in the service manual, but it's always nice to have a real-world description of it too.

You usually don't even need to plug in a 150W iron, as the terminals will quiver in fear & heat up on their own if you come near them with an iron that size. ;-)

I understand. The good thing about it is that at least these are through-hole ICs, rather than surface mount.
Basically, there are two clips near the front (CRT side) of the 'chassis' that let all the boards slide back. I needed to unplug one cable from a small board tucked in between the flyback board and the side edge bacuse it did not have enough slack...One or two of the wires with slack may tend to tangle/hang up part way through sliding back, but will come loose with help.

98% of the equipment I work on is old 1930's-early70's tube electronics with pea sized solder joints and soldered chassis grounds. That cattle prod iron makes those dinosaurs faster to service since I don't have to wait the 10 sec - 5 min a weaker iron takes to heat up a massive solder joint...I like all my soldering on tube gear to be instant melt for speedy repair. I usually do keep a lower watt iron warm for tight spaces and delicate work on my tube stuff, but prefer the big one where usable. I'm a 'bring a gun to a knife fight' type of person.
__________________
Tom C.

Zenith: The quality stays in EVEN after the name falls off!
What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
Reply With Quote
  #40  
Old 03-17-2020, 02:10 AM
tdvab tdvab is offline
VideoKarma Member
 
Join Date: Nov 2019
Posts: 2
Always loved the sony xbr sets. I saw a 30" in a pawn shop a while ago and they wanted $150. I passed on it but a short time later decided I had to have it, so I went back but it had sold. I kept looking and finally located a 34" xbr series 910 with its matching stand (craigs list) for $120 and picked it up. Shortly after that, I grabbed a 30" xbr 910 from a goodwill for $34.95 (which was the same price they had on all of their crt sets of which several were junk). I always wanted a Super fine pitch XBR when they were new, but prices were in the neighborhood of $2000-$3000. Anyway, the 34" began the flashing thing and wouldn't turn on. On checking the web, I ordered the ic that was suggested. Instead of disassembling the tv to get to the chip, I decided the easiest way was to use a dremel tool and carefully cut the plastic away below the chip. I then had easy access to get at the chip. While waiting for the replacement to arrive, I decided to resolder the pins securing the original chip to the board before pulling the original.....and......that fixed it! So I still have the replacement chip for future use but havent been able to use it because both sets are still going strong. This series does not have the atsc tuner but it does have the hdtv super fine pitch tube. I believe this is why the original owners probably got rid of them. Of course I went looking for a stand alone atsc tuner and found a samsung, so now I can watch broadcast hdtv, BUT I mainly use these tvs for my analogue stuff. There are several picture controls (such as clarity), which most tvs dont have .These xbrs can do wonders with laserdiscs, svhs, beta and regular vhs. With vhs going 5 for $1, it pays to have a great crt color tube so you can still enjoy the tape formats. If I would have had access to this tv when dvd first became available, I dont think I ever would have invested in dvd's because, these sets make laserdisc's look downright amazing.
Reply With Quote
Audiokarma
  #41  
Old 03-17-2020, 02:53 PM
JohnCT's Avatar
JohnCT JohnCT is offline
VideoKarma Member
 
Join Date: Jan 2020
Posts: 716
Quote:
Originally Posted by tdvab View Post
While waiting for the replacement to arrive, I decided to resolder the pins securing the original chip to the board before pulling the original.....and......that fixed it!
I've fixed hundreds of those Sonys, and my guess is that you will have to replace that MCZ chip soon.

One of the tricks we used to identify a bad MCZ chip was to simply heat it with a heat gun or a wide blade soldering iron across the top of the chip. If it started, I changed the chip. Heating them would sometimes restore them for a short amount of time. While it's certainly possible you had a bad connection that you fixed by soldering, I can honestly say that I never saw bad solder on the power board.

Some info from the field for site posterity:

There are two board versions - the brown and the green. The brown may have been in the DA1 and the green in the DX series, but I don't trust my memory like I used to.. The brown board is a single side board and it's very easy to replace the chip conventionally. I normally would put down a little liquid solder flux and use Chemwick to clear the pins.

The green board is a double sided affair and the solder goes through the lead holes and stops on the component side. It's a lot harder to replace the chip on the green boards. I used to add some chipquik to the original solder along with flux, then hot air the chip out of the board. It could also be wicked out but I preferred the hot air. I wouldn't use a spring loaded solder sucker on these as the recoil could damage a trace.

I never did this, but some guys would clip the pins of the chip from the top of the board with a *high quality* pair of angle cutters, then heat and remove each pin individually. Alternatively, you could also use a Dremel (if you have the swing room) with a cutoff wheel to cut the pins at the chip's body. Don't rush the cut lest you snag the pin and pull it, and don't go too deep!!

Towards the end of the Sony DTV era, there were TONS of counterfeit chips around. At the end, the only place I would trust to buy any Sony chips is B+D https://www.bdent.com/. I don't know if they have any originals left. The counterfeits would either not work, fail shortly after power up, or trash other parts around the chip. Careful with sourcing the MCZ chips.

Lastly, 98.136 percent of Sony TVs that came in for repair that had a power supply problem only needed the MCZ chip closest to the flyback, so I would only install the one chip - not both.

John
Reply With Quote
  #42  
Old 03-17-2020, 03:33 PM
Electronic M's Avatar
Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,758
My set hasn't had the MCZ fail again but the grey scale will shift red then the entire screen will go red and trip a shutdown. Sometimes I can slap it before it gets too red and it will go back to normal....It got real bad a few months ago and I reflowed some solder on the neck board ICs/heatsinks and it was fine for months, but it is slowly coming back.... Anyone got a more precise/lasting repair method?
__________________
Tom C.

Zenith: The quality stays in EVEN after the name falls off!
What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
Reply With Quote
  #43  
Old 03-17-2020, 03:43 PM
JohnCT's Avatar
JohnCT JohnCT is offline
VideoKarma Member
 
Join Date: Jan 2020
Posts: 716
Quote:
Originally Posted by Electronic M View Post
My set hasn't had the MCZ fail again but the grey scale will shift red then the entire screen will go red and trip a shutdown. Sometimes I can slap it before it gets too red and it will go back to normal....It got real bad a few months ago and I reflowed some solder on the neck board ICs/heatsinks and it was fine for months, but it is slowly coming back.... Anyone got a more precise/lasting repair method?

CRTS on Sonys can get cranky. If the grey scale shifts, the AKB will mute the screen or causing blinking, but if the cathode goes too low, it will draw too much current and shut the chassis down.

Try gently flexing the neck board of the tube and gently tapping the neck of the tube itself. Sometimes, there could be a piece of wayward cathode material that gets caught between the other tube elements. If flexing the board seems to change things, take a close look at the IC mounted to the heatsink (some have one IC for each gun, others have one larger drive IC to cover all three). These ICs run hot and could develop cold joints.

If the tube was the problem, I used to use my modified B&K 467 to try to clean the out by pushing the shorts clear button repeatedly while tapping on the neck. If that didn't help, I'd put the B&K on clean setting and repeat while tapping the neck.

John
Reply With Quote
  #44  
Old 03-17-2020, 03:59 PM
Electronic M's Avatar
Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,758
Quote:
Originally Posted by JohnCT View Post
CRTS on Sonys can get cranky. If the grey scale shifts, the AKB will mute the screen or causing blinking, but if the cathode goes too low, it will draw too much current and shut the chassis down.

Try gently flexing the neck board of the tube and gently tapping the neck of the tube itself. Sometimes, there could be a piece of wayward cathode material that gets caught between the other tube elements. If flexing the board seems to change things, take a close look at the IC mounted to the heatsink (some have one IC for each gun, others have one larger drive IC to cover all three). These ICs run hot and could develop cold joints.

If the tube was the problem, I used to use my modified B&K 467 to try to clean the out by pushing the shorts clear button repeatedly while tapping on the neck. If that didn't help, I'd put the B&K on clean setting and repeat while tapping the neck.

John
Mine is the 1 IC per gun version.

If flexing the IC doesn't change behavior (IIRC it did and the heat sink ground joints were the worst last time) I'll try my B&K 466 on it as a last ditch (ISTR hearing most Sony CRTs die if you try rejuvenation).
__________________
Tom C.

Zenith: The quality stays in EVEN after the name falls off!
What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
Reply With Quote
  #45  
Old 03-18-2020, 04:45 PM
JohnCT's Avatar
JohnCT JohnCT is offline
VideoKarma Member
 
Join Date: Jan 2020
Posts: 716
Quote:
Originally Posted by Electronic M View Post
Mine is the 1 IC per gun version.

If flexing the IC doesn't change behavior (IIRC it did and the heat sink ground joints were the worst last time) I'll try my B&K 466 on it as a last ditch (ISTR hearing most Sony CRTs die if you try rejuvenation).
Going bright red could also indicate a heater to red cathode leakage/short. These shorts can't be blasted because the heater would be damaged, but the heater can be "floated" as a workaround. The heater voltage is provided from a winding off the flyback that provides 6.3 volts but it's anchored to ground.

So, if the heater and any cathode make contact, the cathode will be pulled low towards the heater's ground reference. The lower the cathode voltage, the higher the current drawn and the brighter the screen goes.

What I used to do is to wrap three turns of ordinary insulated wire around the core of the flyback and feed it to the CRT socket at the filament pins. Often, a trace would have to be cut in order to get the CRT filament away from ground.

If done properly, you'll still get 6.3V**, but it will now be a floating ground supply. If the heater and cathode short again, the floating heater supply will get pulled up to the cathode potential of 200 plus volts above ground, but it will still maintain the 6.3 between the pins. Because the filament is no longer anchored to ground, a heater cathode short can't pull the cathode low.

Heater to cathode shorts usually will respond to gentle tapping on the neck of the tube, but not the circuit board flexing.

As far as Sony's blowing up on rejuv, I've done a bunch without issues, but any rejuv on any tube is a last resort option. If you need to, there's nothing to lose.

Sometimes, the clean setting will heat the cathode enough to either burn off any crud that's causing the runaway red condition or even melt the cathode and stabilize it.

If the tube is cranky and it's not a filament issue, then try a cleaning.


** With regards to wiring a floating ground supply: you must be careful not to exceed 6.3VAC filament voltage as even a couple of tenths will shorten the balance of the tube's life considerably, and this goes for all CRTs, not just Sony. Also, because the filament supply is sourced from the flyback (15Khz, not 60hz), cheap meters will give false readings of the voltage. A True RMS meter will read the high frequency AC voltage accurately. This is important.

Once you wrap the wire around the flyback core, zip tie it into position as moving it up and down will "tune" it and affect the voltage. Add an appropriate low value 5 watt resistor in series to get the voltage to 6.3 or just under.

John

Last edited by JohnCT; 03-18-2020 at 05:06 PM.
Reply With Quote
Audiokarma
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 02:49 PM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.