Dynex DX-32L150A11 Standby Blink

[tom66]

Re: Dynex DX-32L150A11 Standby Blink

Just remember a cap will show short if other things are in parallel, but from that schematic if it's at least close there isn't -much- on that rail. Maybe 10~15 caps tops.

[ohmmy]

Re: Dynex DX-32L150A11 Standby Blink

Hmm so I continuity tested both ends of that CS38 cap with the output pad of the regulator I removed and meter beeped both times, will try to remove it and see what happens after I place regulator back in.

[tom66]

Re: Dynex DX-32L150A11 Standby Blink

Looks to be different variant then, is that possibly wrong main board for this set?

[ohmmy]

Re: Dynex DX-32L150A11 Standby Blink

Reading is without regulator, and I'm sure there's not even any pads for another resistor there. Also I found one small smd capacitor near processor CS38 that measures 0 ohms as well as two others in the area but none of which are on the 3.3v circuit shown in the schematic that also measure 0 ohms.

There are lots of caps, inductors shown in schematic that I can't find on the board

[tom66]

Re: Dynex DX-32L150A11 Standby Blink

The schematic may be slightly different then, but if the general blocks are there, should be fine, is that reading with or without reg in place? Sure you did not accidentally pull off it while removing reg?

[ohmmy]

Re: Dynex DX-32L150A11 Standby Blink

I only have R603 on the adjustable leg of that regulator, it's supposed to be 510ohms but it measures 313ohms, that's in circuit. Does it need to be out for accurate reading? Would the low ohms create the problem?

[ohmmy]

Re: Dynex DX-32L150A11 Standby Blink

Here's a close up pic of the area I removed the regulator and where x601 connector is on left

[tom66]

Re: Dynex DX-32L150A11 Standby Blink

Other possibles
C529, C538, C528, C531, C533, C520.
You can lift: L505, L624, L504, L502 to isolate these rails and capacitors, may be easier.
If short disappears on one, then you know where to look.

Predominately a short to ground that low is almost always a capacitor or FET, and I can only see capacitors on that line.

Could be hard to read 5/6 on board?? Do check common components to see if general layout is close.

[ohmmy]

Re: Dynex DX-32L150A11 Standby Blink

The connector on my mainboard with the 5v is at connector x601 but I don't see it anywhere in the manual? Just x501

[tom66]

Re: Dynex DX-32L150A11 Standby Blink

Page 31 and others in that area. Just confirm that it is correct schematic, check a few component references to be sure, for example reg should have R603, R604 nearby.
The short is on VCC3.3V if N602 and sch is correct, which is standby 3.3V rail. (Don't confuse with 3.3V_NORMAL)

[ohmmy]

Re: Dynex DX-32L150A11 Standby Blink

The part number on the regulator is 1117

I've already tried lifting c661 and replaced c660 both made no difference

what page of the manual is the mainboard schematic?

[tom66]

Re: Dynex DX-32L150A11 Standby Blink

That is a 3.3V reg (adj setup) on the schematic -- is that correct?
Lift C661, see if short goes.

[ohmmy]

Re: Dynex DX-32L150A11 Standby Blink

N602

[tom66]

Re: Dynex DX-32L150A11 Standby Blink

Which reg is it that has the short? Nxxx?

[ohmmy]

Re: Dynex DX-32L150A11 Standby Blink

Awesome! Thanks

[tom66]

Re: Dynex DX-32L150A11 Standby Blink

Amazingly, yes!

Detailed schematic of power board and main board.

[ohmmy]

Re: Dynex DX-32L150A11 Standby Blink

Damn. Know if I can find the service manual/schematic for this anywhere?

[tom66]

Re: Dynex DX-32L150A11 Standby Blink

That sounds like you do have a short. The next thing to do would be to try tracing the short on 1.8V -- but unfortunately you WILL need something like a 1.5V power supply (maybe a 1.2V NiMH.) An ordinary alkaline cannot supply enough current.

[ohmmy]

Re: Dynex DX-32L150A11 Standby Blink

But from output pad of where the regulator would be to ground I get .2ohms

[ohmmy]

Re: Dynex DX-32L150A11 Standby Blink

From 5v pin of main board to ground I get infinite resistance