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Pete
Pete, Electronic Engineer
Category: TV
Satisfied Customers: 17276
Experience:  Over 16 years of experience installing and repairing electronics.
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Sony KDS-R60XBR2. Was displaying a fan error, replaced the

Customer Question

Sony KDS-R60XBR2. Was displaying a fan error, replaced the main fan, verified the other 3 would run when power was applied (External power supply) and turned on the TV. Came right up. I had to re-route some wires so I disconnected the 5 or 6 cables in the area of the fan, routed them properly and then buttoned the TV up and turned it on. It would power up for a few seconds, then the fans would stop and it would display 5 red blinks on the front panel. (Bad lamp ballast per my service manual.) I obtained a new ballast and installed it. Same issue. 5 red blinks on the front panel.
JA: What's the make and model of your tv, and has turning it on been a problem in the past?
Customer: Sony KDS-R60XBR2. No previous issues.
JA: Does the TV menu work? Do you have the same problem on all sources/inputs?
Customer: Can't see the menus if the lamp won't light.
JA: How long has this been an issue? What happened right before this popped up?
Customer: .
JA: Is there anything else the TV Technician should be aware of?
Customer: no
Submitted: 2 months ago.
Category: TV
Expert:  Pete replied 2 months ago.

Hi, I'm Pete. Welcome to JustAnswer! I'm reviewing your question now, and will post back with your reply ASAP.

Expert:  Pete replied 2 months ago.

Can you use a digital multimeter to verify the input and output voltages of the lamp ballast board?

Customer: replied 2 months ago.
As far as I can tell, there is no input voltage to the supply. Inserting the meter's probes in the cable that comes from the main power supply, I see 0.07VDC with the set off. When I attempt to turn it on, I do not see a change.Looking at the schematics in the service manual (https://elektrotanya.com/sony_kds-r60xbr2_kds-r70xbr2_chassis_sp3.pdf/download.html) I found where the input power comes from (Page 43, Block Diagram 10, upper edge) and it appears it should be 400V. Wondering if the rectifier or regulator in that circuit is bad. Take a look and let me know if you think I'm on the right track.
Expert:  Pete replied 2 months ago.

Yes, it definitely seems you are on the right track - there should be voltage going into the ballast. It could be a bad rectifier or regulator or even a dried up electrolytic capacitor.

Customer: replied 2 months ago.
Interesting that it was working until I shut it down to change cable routing then when it was powered back up, it started flashing errors.Not sure if I can test the rectifier in circuit or not. Any way to test the caps in circuit? Not fun to pull each one to check.. Did you look at the schematic? If so, am I reading this right? There should be ~400V (Assuming DC since it's "downstream" of the rectifier) heading to the ballast?
Expert:  Pete replied 2 months ago.

Could any of the wiring have been disturbed?

Have you tried several reboots in quick succession?

You can test the larger caps (>1uF) in circuit using an ESR meter - it will put a low voltage through the cap to test it. However if this cap is in parallel with other ones, or if you really want to be sure it is working, you could just lift one side of the capacitor and measure it that way. Or you could make a DIY in-circuit cap meter using a square wave generator and scope.

Customer: replied 2 months ago.
I think you've over-estimated my abilities. :) I'm just a handy guy who can (sort-of) read a schematic and drive a soldering iron. I do not have access to a scope, but I'm not averse to building a gizmo to help diagnose. I'm not sure either of my meters has ESR capabilities. One *does* have a capacitor test function, but I'm not sure if it's accurate. (Likely a user error)I'm comfortable poking around, just don't know what exactly to test..
Expert:  Pete replied 2 months ago.

Ok, in that case your best option would be to just remove one cap leg from the board to test it out of circuit :)

Customer: replied 2 months ago.
Ok, took the main chassis out and starting checking continuity between the connector and the rest of the circuit. It appears R6500 (0.47, 1/2W 10% Fusible) is open. I get no ohm reading and no "beep" when I check continuity. R6102, another fusible resistor (0.1, 1/2W, 10%) shows 3 Ohms and I do get a "beep" when checking continuity.I've attached the block diagram schematic for this circuit. Clearly, if R6500 is open, no power will flow to pin 1 on the connector. Anything else I can check to verify there's nothing else bad?
Expert:  Pete replied 2 months ago.

Good catch! R6500 is a fusible resistor, so replacing it should get you up and running again.

If not, you will need to replace it anyhow to continue troubleshooting.

Customer: replied 2 months ago.
I've been looking on Mouser and DigiKey for a replacement. Can't find anything that says, "fusible". I *did* find a 0.47Ohm, 1W resistor at the local Fry's. Original is 1/2W. Will that one work without potentially cooking something else?
Expert:  Pete replied 2 months ago.

Yes that will work just fine.