BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

[Andyd1970]

Hi Guys,

Through all the great help for you guys especially Tom66, I have learnt alot about fault finding TV's. But have my first one that is totally dead!

It contains a 17PW80 V2, with the very long caps, I cannot see any leaking or domed caps. Any suggestions guys?

Andy

[tom66]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Here's the schematic.
http://www.tgohome.com/ServiceManual...h=Submit+Query

So, they use 22" power supply in 24" LED, makes sense...
Test voltages on PL703.

[Andyd1970]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Hi Tom,

Thank you for info, I take it as from my old memory pin 1 is denoted by a small black dot on the PCB for PL703?

If so I have nothing on pin 7 and pin 9 and only -170mv on pin 11. That was measure with the PSU connected to the TV.

Andy

[tom66]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Check voltages across: C279, C730, C731, C734, C735, C775; any which are not present ignore for now.

[Andyd1970]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Hi Tom,

Sorry for the delay, have been so busy

See below the following readings:

C279... 0V
C730....0V
C731....0V
C734....Not present
C735....Not present
C775....Fluctuation of readings from MV to about 32v

Andy

[tom66]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

OK, check of which present:
D708, D709, D710, D712, D713, D715
for shorts (diode test, both ways, in circuit.)

And voltage across: C715 (On primary), C705 (400V cap) very carefully

[Andyd1970]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Hi Tom,

Details Below:

D708...S/C
D709...S/C
D710...S/C
D712...OK.... 0.430V/0.823V
D713...OK... 0.430V/0.823V
D715... Not present
C715...11.8V to 15v ish
C705...326V

[tom66]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Remove each of D708, D709, D710 and test out of circuit for shorts. You can briefly run the set with whichever diodes are still good. (One or two, max one minute running time.) CRAPPY VESTEL parallel three diodes. If one diode gets slightly hotter than the other two, it ends up taking more current than the others, causing it to heat up more, causing it to take more current.... I'm sure you can see this cycle will eventually lead to a diode failing. Built to fail!

[Andyd1970]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Hi Tom,

Sorry for the delay in replying, I have followed your advice and found D710 was short, the other two were fine, so I removed D710 switched on set and it worked OK Fantastic and I am certainly learning about the crappy VESTEL PSU's!! Just need to buy a replacement diode, can you recommend a good supplier as dont want to use Maplins after your warning last time The info on diode is:

SB5100 PEC1289

Andy

[Andyd1970]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Hi Tom,

Just checked the circuit diagram and it shows UF5402 below D710. Just dont want to buy from a crap supplier, would it be best to replace all three?

Andy

[tom66]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Unlike capacitors, counterfeit/dodgy UF5402's are very rare.
http://www.ebay.co.uk/itm/UF5402-DIO...item5ae710d75c
should be OK.

Maplin are fine for them too, but they don't stock them. They're nearly useless -- apart from a few lucky hits. I'm not sure why they bother at all.

[tom66]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

I would also suggest you purchase thermal epoxy to stick the diodes together and make sure they run at the same temperature. It would also be advisable to replace all of D708-D710 with a new diode from the same order, to ensure they will have closely matched specifications (same batch of silicon.) The design of this power supply is bad in the first place, there's not much you can do unfortunately.

[Andyd1970]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Hi Tom,

Thank you for the advice I will buy all three and get some thermal epoxy.

You are a star!! thats another TV you have saved from the dump

Andy

[tom66]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Use the epoxy for 24V diodes too.

I have considered picking up some smaller Vestels for sales to students. 24" is ideal for bedroom etc. And they are often easy to fix due to the cheap components used.

[Andyd1970]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

No problem I certainly will do. Well they certainly are welll laid out inside and easy to repair from my experience

Thank you for all your help.

Andy

[mutttt]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Thanks guys I had the same diode problem

[satinser]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Many thanks I too had same problems changed all three to make sure.

[PatM]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

Reading this at work today :-) and searching Vestel 17pw80- I smile because Ive just started to work on one of these. The 22'' set is DEAD and I obviously went for the PSU straight away- finding the usual stick caps ok- surprise, then the diode short, which I duly replaced with another like-minded soul from another trashed Vestel board- but still DEAD, not LED on the front of the set- nothing. Any pointers as to what's been fried by passing a/c over it? Theres a guy on ebay selling a kit of 3 components to fix this board but I doubt 3 will fix it as Ive looked at the obvious (ive got the inline fuse shorted at present, as I managed to blow that while testing... I can buy a board for £50 but that makes short work and an expensive repair. I too have the schematic, but stopped short of measuring voltages as it was so cold in my workshop last night!

[flocko]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

I have repaired 5 or 6 of these boards and have only ever seen the Diodes go bad you need to pull them all and replace all 5 with new then it should work, and do as Tom says use thermal epoxy to hold them together and leave the legs long Flocko

[PatM]

Re: BUSH LED2497ODVDFHD, 17PW80 V2, Dead!

No, the other 2 diodes where ok- but Id managed to solder a duff joint on the fuse Id shorted out with a scrap of old wire off a resistor- Doh! Wondered why I had no output /reference voltages. Its usually something simple! That set is only just a year old and cost me £34 off Ebay- it will do my garage a treat and its got a DVD built in. Feel a bit sorry for the young couple I collected it from.