5 Blinks on Sony KV-32fs120 - "KV32FS120.pdf" (0/1) 6.9 MBytes yEnc

On Sat, 16 May 2009 00:45:48 -0400, What_Me? put finger to keyboard and composed:

Nobody (?) can see it. This is not a binary group.

Better to upload your manual to a file sharing site and post a link to it.

- Franc Zabkar

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On Sat, 16 May 2009 19:35:05 -0400, BushPilot put finger to keyboard and composed:

Pages 8 & 9 suggest that you have an IK (AKB) fault.

IK = cathode current (?) AKB = automatic kinescope bias (automatic colour/white balance)

The manual points to a possibly faulty M board, or misadjusted G2 setting. If yours is an old set, then I'd suspect a tired CRT.

"If the RGB levels do not balance within 2 seconds after the power is turned on, this error will be detected by IC001 (M Board). TV will stay on, but there will be no picture."

I'd be looking at the C board on the CRT neck, specifically IC702. IC702 provides IK information to the M board.

Here is the datasheet for IC702 (TDA6108JF):

- Franc Zabkar

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Thank you Frank for you advice. I will examine the IC702 datasheet you mentioned. I don't know if my voltage reading were of any use. it seems bizarre that the rectifier right off the mains input would not output higher voltage coming right off 123v.

I'll keep you posted. Thanks again.

On Sat, 16 May 2009 20:56:58 -0400, BushPilot put finger to keyboard and composed:

It appears that the uP is switching your TV off in response to a fault condition. However, the documentation states that an IK (AKB) fault should allow the TV to remain on, but with no raster.

I'd also check for a short on the B+ (135V) supply rail.

- Franc Zabkar

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Sounds like you may be referencing to chassis ground. This won't work measuring the input side of the SMPS. You must find a "hot" ground for a reference.

Mark Z.

Ok tested IC702 onboard and each test is while powering up the set.

Grnd is pin 4. pins 1,2,3 read .4 v then drop to 0. pin 5 maxed to 2.4v and dripped to 0 pin 6 maxed to 9.1 and dropped to -.112v pins 7 maxed to 3.1v pins 8 maxed to 2.1v pins 9 maxed to 3.1v

FBT (T503) EY519 to EY513 Maxed to 23.72v with a resistance of 28.72k EY514 to EY514 maxed to 14.91v with resistance of 28.8k

If I remove the IC702 to check it, should I be checking the resistance between grnd and v pins (1,2,3 & 7,8,9)?

On Mon, 18 May 2009 15:34:30 -0400, BushPilot put finger to keyboard and composed:

There is an inconsistency between what the manual is telling us and how the TV is behaving.

It would seem that the TV is trying to start, but the uP is sensing a fault which then causes the uP to shut down the power supply by opening the relay.

I'd check the resistances between diodes D530, D531, D534 and ground.

You could desolder the supply pin to IC702 to isolate it. Measure the resistance between its supply and ground pins.

One other thing you could try is to bridge the contacts of relay RY600 with a piece of wire, but this will defeat the TV's protection, so be very careful. There is an overvoltage protection diode on the B+ rail, and fusible resistors in the FBT secondary outputs, so any damage

*should* be restricted to these devices. I take no responsibility for any consequences, though.

If you see a horizontal white line, quickly turn off the TV, otherwise you risk burning it into the CRT.

- Franc Zabkar

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One thing i forgot to mention, ever since I got this TV it always produced this loud buzz when turning it on. I would hear "click" 1 second delay "BUZZ!" then the led would flash a few times and the picture would appear. My 18 month kid kept cycling the power on it and it eventually died. He's very disappointed he can't turn it on and off any more. :D

Anyways, I'm not giving up on it. Were moving in July and if I haven't fixed it then, I'm going to get an LCD TV.

This set was bought in June 2006 so it isn't very old - if I had gone for one of those crappy extended warrenties I would be in a better mood.

Thanks everybody for helping my education.

Kevin McCarthy

Yes Frank, the TV is trying to start, as since it has been dead, on occasion it does produce a febble buzz compared to the loud BUZZ! it did produce when it was working. This buzz is no longer occuring, and the febble attempt is random and seems to have given up, too.

I picked up Homer Davidson's Consumer Electronics Troubleshooting And Repair Handbook (Mcgraw Hill-1999).pdf I'll be going over the SMPS testing section :o/

On Mon, 18 May 2009 21:21:37 -0400, BushPilot put finger to keyboard and composed:

I had a closer look at the circuit and it appears to me that the relay can be controlled by both the uP and a separate protection circuit. See the bottom middle section of page 88 of the service manual.

When the TV shuts down, measure the voltages across R599 and R598. If they are both around 0.6V, then the OCP latch has operated. This could be due to an overcurrent on the B+ supply rail, or a missing vertical deflection pulse.

If the latch has not operated, then the uP would have opened the relay.

- Franc Zabkar

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Haven't read the entire thread too closely, so apologies if I duplicate any previous advice;

1. Check the obvious - see if the horizontal output transistor is shorted. Also check to see if the 200 volt line is shorted to ground through the CRT drive IC.
2. Check the 200 volt line at power up. If it only goes to 130 volts (briefly - I know) then the horizontal isn't firing up.
3. If no 130 volts, check the power supply switcher FET's. Actually, it's quicker just to check R615 in the power supply, since if the FET's are bad, this resistor will be open.
4. If the resistor is good but still no 130 volts, replace IC 600. It is a common failure item.
5. If the FET's are bad, likely the flyback is bad.

Mark Z.

I assume you realize that if the chassis should happen to fire up with high voltage, and the anode, ground and deflection aren't hooked up, disaster will follow!

Mark Z.