Samsung HT-Z310 Help please "protect"

larserik1 · Guest

Hi I'm Lars I'm trying to fix an old surround sound unit I have here.
It was fixed multiple times under warranty until it ran out.

I have pretty limited knowledge on electronics so if you have the time to help you may need to explain things slowly for me.

The unit was starting then shutting down and saying protect, this was with no speakers plugged in.

I removed the cover and through some trial and error found that if I disconnected the AMP pcb it would start and run a disc ect.

I then found on the main power board that # R91 a 1/4w 1k resistor was burnt, also found that a diode #D31 was blown in 2 pieces and 3 capacitors were also swollen on top C92 C93 and C94.

Now I replaced all these parts with new ones, It then didnt start at all just a flickering standby light which I think I read somewhere was a short circuit? Now if leave the AMP pcb plugged in and I cut the #D31 diode back out it would start again say protect and shut down.

If I disconnect the AMP pcb completely again (with the #d31 diode still not in there) it will start and run a dvd and can watch it on tv just no sound obviously.

Its not essential that I fix it just thought it would be fun and could save some dollars trying to do it.

Thanks in advance.

Guest · Posted: Mon Oct 19, 2015 7:50 am Post subject:

I cant seem to get the email to register with, and I cant post the photo of the schematic as a guest Sad

jts1957 · Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away

http://forum.eserviceinfo.com/viewtopic.php?t=98813&highlight=htz310

Service Manual for either model is also available at elektrotanya.
_________________
You're over there, I'm over here.

larseirk1 · Guest

Thanks for that link mate, looked high and low for that.
I have seen that other thread ( where I got my ideas from) but It he found a dry solder, I can not see anything like this on either board.

jts1957 · Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away

Was just pointing out the existence of that other thread and the fact that the Model codes may end in a different suffix - hence schematics may also differ.

Person who found dry joint was NOT the OP.

I think in end you'll find one or more output ICs to be involved.
D31 is for the 12 volt supply.
The other 34.5 volt/PVDD supply looks to be exclusive to output ICs.
What voltages (or resistances) are you measuring on those lines.
_________________
You're over there, I'm over here.

larserik · Joined: 19 Oct 2015 Posts: 20 Location: Australia, QLD

Ok so here is where the dumb questions start....

What are the output IC's?

Where should I be testing voltages between?

Could you mark the points on the schematic for me?

If I'm to much hard work I understand, just trying to self teach myself.

_________________
..

jts1957 · Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away

http://imgur.com/AF1xWLC
C92/C93/C94 negative terminals = ground reference - Black meter lead connects to this for voltage or resistance readings.
_________________
You're over there, I'm over here.

larserik · Joined: 19 Oct 2015 Posts: 20 Location: Australia, QLD

jts1957 · Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away

Pin 1 - 12 volt
Pins 7, 8 or 9 = PVDD (34.5 volts)

Oh, look. there are some more grounds you could use (Pins 4, 5 or 6)
_________________
You're over there, I'm over here.

larserik · Joined: 19 Oct 2015 Posts: 20 Location: Australia, QLD

Thanks mate your a legend, that is a lot easier for me to understand I will test it tonight and let you know how I go, I'm due for a new multi meter are the auto ranging ones better or just a standard one?
_________________
..