Samsung hp-t5064 no vs voltage

[microvibe]

Have samsung hpt5064 was a few bulging caps they were replaced by someone but set would turn on but no video can't determine sound . All voltages are present except VS . 5v 18v VA etc is there. I removed psu jumper ed psu on and vs on still no vs so it's somewhere problem on vs supply . Large caps all have 387v across. Which fets are for vs line to start testing for shorts.

[tw2005]

Re: Samsung hp-t5064 no vs voltage

https://www.youtube.com/watch?v=dVaC2KVVLvs

may be worth checking the ymain is not shorted and also upper buffer board also not shorted before you get too far into it just in case.

[microvibe]

Re: Samsung hp-t5064 no vs voltage

I pulled psu out turned it on jumper ed correct pins no VS if u main at fault could have blown psu? Still need repair psu .

[microvibe]

Re: Samsung hp-t5064 no vs voltage

Anyone have schematic of this psu or which fets are for vs

[microvibe]

Re: Samsung hp-t5064 no vs voltage

On back side I did some voltage tests I have 375v going to transformer but nothing on the secondary side

[microvibe]

Re: Samsung hp-t5064 no vs voltage

Any ideas where to start on this psu or good diagram out there even simple person can read

[microvibe]

Re: Samsung hp-t5064 no vs voltage

Bump

[rccrasher65]

Re: Samsung hp-t5064 no vs voltage

Post 2 answered your question on VS line. Watch the video!

[microvibe]

Re: Samsung hp-t5064 no vs voltage

I watched that video don't have scope. But I tested those fets out of circuit they were short and 1 smd surface mount so I replaced the 2 fets and smd now blows fuse by ac in. I removed fuse by the 2 fets and now fuse doesn't blow by ac in line. But the 2 fets I replaced show short I have no idea can't find any other shorts

[microvibe]

Re: Samsung hp-t5064 no vs voltage

Pulled 2 fets I replaced and there blown again. Possible transformer shot? Without fets in I don't blow fuses . Don't have ring tester any other way test transformer?

[microvibe]

Re: Samsung hp-t5064 no vs voltage

Any ideas

[flocko]

Re: Samsung hp-t5064 no vs voltage

Check ZD 801/2/3/4,DS 803/4 and RS 812/3/5/5 these will fail along with the two VS Fets and should always be replace on all BN44-00159/ 00160 power boards

[microvibe]

Re: Samsung hp-t5064 no vs voltage

Ok thanks will check those too

[flocko]

Re: Samsung hp-t5064 no vs voltage

You will find that the SMD diodes and or zeners are shorted, but check the resistors as well, you will find the schematic listed under BN44-00159 it is the 42" unit but runs the same components. common fault no VS there are repair kits out there(shopjimmy ),but will have more parts then you need. I hope this is of help to you

[microvibe]

Re: Samsung hp-t5064 no vs voltage

Zd all showed open one way and 0.713 other in diode mode. The DS 803 804 were .020 in diode mode RS 812 was .020 rs813 open rs814 .020 rs815 .020

[flocko]

Re: Samsung hp-t5064 no vs voltage

just to help you on your way, ZD801/2/3/4 zeners marked 10 = 22v 5ma LM3Z22VT1G diodes DS803/4 marked 5A= 5a 70v switching LMDL6050T1G , RS812/814=10R and RS813/815 =10K. Flocko

[microvibe]

Re: Samsung hp-t5064 no vs voltage

So rs813 is blown open would that cause fets to blow again? Rest seem ok unless the 2 ds803 804 might need take them out circuit retest

[microvibe]

Re: Samsung hp-t5064 no vs voltage

Rs813 is 10k rs815 is shorted . Looks like rx814 and rx816 are short too but doesn't blow that fuse .

[microvibe]

Re: Samsung hp-t5064 no vs voltage

Ok I am spaming my post. I removed the resistors all test fine out of circuit removed ds803 and ds804 test fine out of circuit open one way .703 other way in diode mode. Thought I was onto something back to square one

[flocko]

Re: Samsung hp-t5064 no vs voltage

Have you done a voltage test on the zeners ? it is no good just doing a test with meter set in diode mode, did you replace the insulators on the Fets when fitting them. Have you found the schematic for this board yet (BN44-00159)