I have a 13" Sansui TVM1316E

It had a problem in the vertical deflection and the bottom of the image was not linear and about an inch above the bottom of the screen.

I replaced all the caps on the board in the area of the LA78040n deflection-amp chip and it seems there was a dead 10uf cap there that was the cause.

Anyway it now has good video once again... but somehow after working on it there NOW suddenly seems to be a low freq oscillation in the audio about 10hz or so. It starts out quiet ... but then about 15 seconds after turn on and it starts the pulses, low-freq-buzz or ticks at that rate... though sometimes it will get faster then slow down again.

I don't have a schematic ... but there is a 7511 chip in the audio section.

I can't trace this noise as I have no clue where I'm going.

Do any of you guys have this schematic for me?

Does anyone have any idea what is wrong or if it was something I did while replacing sic caps in the Vert Deflect. section?

Try a search for data on the sound IC. That may give you enough data to figure out what's going on without a schematic for the set. I once managed to fix the vertical on a set that I didn't have info on by searching for the relevant IC data. Good luck.

:I have a 13" Sansui TVM1316E
:
:It had a problem in the vertical deflection and the bottom of the image was not linear and about an inch above the bottom of the screen.
:
:I replaced all the caps on the board in the area of the LA78040n deflection-amp chip and it seems there was a dead 10uf cap there that was the cause.
:
:Anyway it now has good video once again... but somehow after working on it there NOW suddenly seems to be a low freq oscillation in the audio about 10hz or so. It starts out quiet ... but then about 15 seconds after turn on and it starts the pulses, low-freq-buzz or ticks at that rate... though sometimes it will get faster then slow down again.
:
:I don't have a schematic ... but there is a 7511 chip in the audio section.
:
:I can't trace this noise as I have no clue where I'm going.
:
:Do any of you guys have this schematic for me?
:
:Does anyone have any idea what is wrong or if it was something I did while replacing sic caps in the Vert Deflect. section?

:I don't have a schematic ... but there is a 7511 chip in the audio section.

I would scope the input of the AN7511 Audio Amplifier chip; which is pin 2 looking for your 10hz buzz. If you don't see it on the input then it has to be in the AN7511 circuit which is fairly simple. You can check the output which is pins 6 & 8 for the buzz; since those should directly feed the speaker you should definitely see the buzz there.

Pin 1 is the standby input. It should have a cap and resistor in parallel to ground. The cap will typically be an electrolytic around 10uf; the pull down resistor will typically be around 270K ohms.

Pin 2 is the audio input.

Pin 3 is ground.

Pin 4 is the "Mute" input. Expect another electrolytic cap (typically 1uf) and resistor (typically around 100K ohms) to ground.

Pin 5 is VCC.

Pin 6 is positive audio output to speaker.

Pin 7 is ground.

Pin 8 is negative audio output to speaker.

As you have already replaced capacitors and had a bad 10uf; a good suspect would be the mute capacitor and resistor followed by the standby capacitor and resistor; assuming the buzz is not coming from the input to the amplifier chip.

Richard

Thanks Richard! That really helps a lot!!
I'll try that.
I did look up the 7511 chip the other day... it did seem rather simple but couldn't scope it at that time, because I had another radio on the bench that's under repair.

So now I'll have to get back into this TV again next week.

... I had almost kinda given up for a while and took it off the bench..

Then, to boot.... I also had the good fortune to find a super nice replacement 15-inch flat-screen HD for very little $$. (under $100 with Amazon gift credits)
It's an "Axess TVD1801-15"
... so my burning urge to fix this thing sorta dwindled... lol