Vestel 17PW16-2 troubleshooting

[Ian Paul]

Re: Vestel 17PW16-2 troubleshooting

I think you may have to buy a pack of 5 on RS.

[Shotgun25]

Re: Vestel 17PW16-2 troubleshooting

I think you may have to buy a pack of 5 on RS.

Yeah, that's what I'm trying to do so I have spares, but the RS website wouldn't let me amend my invoice address, i'm on the phone with them and they added my basket items I was going to buy and there was approximately a £1.50 discrepancy in the price, so I'm on hold at the moment.
Lady just come back and said because I'm a private individual, there is a £4.95 shipping charge, I said on the website it is showing as free, she seems to have muted my call and hopefully is talking to someone. The difference doesn't add up so I know it's a load of rubbish.

If they wont amend, I'll be ordering Farnell.

Edit 1: Got it sorted. What an effort. Understaffed on phones, amended my customer address (which seems to force invoice address and I assume card payment address) and was told the change would be in effect from tomorrow, so offered my phone order. Read items I wanted to order, but had mismatch on total. When she came back after checking with someone what happened, said it related to private individual and was subject to £4.95 shipping, told her it was free on website, went on hold, came back with no explanation and went straight to can I have your card details. I asked her to confirm the total and she confirmed the total without VAT, asked her to confirm total with VAT and she muted me and then confirmed the correct total. Then paid on card and seemed to be rushing to say bye, but then said sorry for the hold up.
I feel sorry for the staff at RS!

[vinceroger69]

Re: Vestel 17PW16-2 troubleshooting

luckily i have a rs branch about a mile from me although i only do repairs as a hobby they will let you collect stuff from the trade counter so thats good too, the only downside is yes it says next day free delivery this isnt always the case the odd time its been 3 days but hey the prices are good and im in no rush.

[Ian Paul]

Re: Vestel 17PW16-2 troubleshooting

Although I havn't used them in a while, Cricklewood Electronics and Grandata (both in London) were quite good.

[vinceroger69]

Re: Vestel 17PW16-2 troubleshooting

years ago used grandata for crt tv stuff i find wiltsgrove ltd in birmingham good for parts at resonable prices too.

[Shotgun25]

Re: Vestel 17PW16-2 troubleshooting

Hi all,

Thanks for the tips on less corporate vendors, I'll bear them in mind for future purchases.

The diodes arrived today, albeit to my home, not where I ordered them to (the reason for calling RS in the first place), and the PSU turns on now and I have no blown fuses.
I can hear a feint "ticker-ticker-ticker" from a transformer (think TR807).

I get 322v at C819 when sat on the bench not connected to anything but mains. Is that suitable or does it indicate any issues? I'm sure I've read that it should be 380v.

Additionally I don't seem to get any of the voltages on PL815, pin 11 and pin 12 are both 1.318v and the schematic labels those pins as 3.3v standby.

According to a foreign language website and google translate I think I've got to look at the PFC circuit, namely D824, IC802 =12v and R829 to start with.

Thanks so far, at least there seems to be a future for this board and the Technika 40" that it belongs to

[vinceroger69]

Re: Vestel 17PW16-2 troubleshooting

im pretty sure it should be around 400v across C819

tom66 posted this in another thread with the same psu and low pfc voltage so maybe worth checking all of these parts

That is the PFC controller.
Most likely, you will find the PFC MOSFET is also shorted.
This is repairable with the schematic.



Replace Q803, IC802, R823, R977, R829, R830, F800.

Check D824.
Check C819 as it could be bad causing this failure.
Check ohms across C814 with IC802 removed, should be several kohms.

"Bulb test" the board before properly powering up. PFC should work ok with backlight inverter removed and 100W series lightbulb.

(NOTE: Schematic shows "IRF7314" - this is COMPLETELY wrong! IC802 is FAN7529.)

[Shotgun25]

Re: Vestel 17PW16-2 troubleshooting

Hi,

Thanks for the info. IC802 was replaced as part of the kit and it does read FAN7529 so that it good. Another schematic error seems to be the F800 is listed as T3.15A but the board has T2.5A printed on it.

Also could you elaborate on bulb testing DO's and DONT's, how to do it safely as I'm new at this and the 240V going is has always kept me on my toes. Had a college tutor who said he worked on some CRT TV's and he warned of it biting you, said if you ever feel around inside CRT TVs use the back of your hand so when your hand clenches because of the shock, you clench away, not onto whatever you are touching.

I'll not be touching things without multimeter probes in my hand, but I'm always as steady as I can be when measuring.

So if you have time and some knowledge, please share so I can learn something new and be safe at the same time.

Also for reference here is the Turkish language website with Vestel Schematics galore.

Google Translate Link - https://translate.google.co.uk/trans...-text=&act=url

Direct Link - http://www.arizanotlari.com/2015/07/...ed-plazma.html

EDIT- found this link, I assume this is what you are referring to. http://www.bristolwatch.com/load_lamp.htm

A quick explanation of how you personally do it, would be really helpful as it mentioned doing it in series, I'd assume to do that, I would have to break into the circuit and place the bulb, kind of like for measuring current with an ammeter?

[vinceroger69]

Re: Vestel 17PW16-2 troubleshooting

how i test is ive got a old extension lead about three meter all what i did was too cut the outer sleving at about the centre of the lead then just cut the brown mains wire and placed a bulb holder there then just plug one end of the extension lead in to the wall as usuall and then plug the tv mains plug into the extension socket i use a 100w bulb if theres a short your bulb will glow bright and no new parts on your repaired board should blow.There are many diffrent designs budm has a good one too hes made but mine works ok and had parts around so cost nothing to make but as your psu isnt blowing any fuses etc now its up too you if you use one.

[Shotgun25]

Re: Vestel 17PW16-2 troubleshooting

how i test is ive got a old extension lead about three meter all what i did was too cut the outer sleving at about the centre of the lead then just cut the brown mains wire and placed a bulb holder there then just plug one end of the extension lead in to the wall as usuall and then plug the tv mains plug into the extension socket i use a 100w bulb if theres a short your bulb will glow bright and no new parts on your repaired board should blow.There are many diffrent designs budm has a good one too hes made but mine works ok and had parts around so cost nothing to make but as your psu isnt blowing any fuses etc now its up too you if you use one.

Excellent, thanks! I'll get that sorted this summer to add to the small tool set I'm amassing.

My board never had R829, is that a problem?

I'll check the rest of the components when I'm home to see what was replaced as part of the kit and what I have yet to check/change.

[vinceroger69]

Re: Vestel 17PW16-2 troubleshooting

vestel schematics do vary im sure reece mentioned that, so if its never been fitted i wouldnt worry what you need to do is re test all your new parts and make sure none have blown as ticking sometimes indicates a shorted part somewhere so really you have to start testing all parts.

[Shotgun25]

Re: Vestel 17PW16-2 troubleshooting

Having just started measuring the resistance of various parts, I noticed that I hadn't soldered in my IC807 after removing the original part, evident on picture 2017_05_06_IMG_6059.jpg.

I'll update the post with any problems or successes when I have soldered it in.

EDIT: I now have 330V at C819 - looks like I'm back to testing the new parts I put in there again.

C819 has 211.8uF, 0.36ohm ESR and 1.32Mohm resistance - all in circuit. Does that sound normal?

EDIT 2: I'm only getting a voltage reading on the following pins on PL815

Pin 11 - (3.3VSTBY) reads 1.4v when it's charged which takes a while.
Pin 12 - (3.3VSTBY) reads 1.4v when it's charged which takes a while.
Pin 13 - (5VSTBY) reads 0.119v-0.123v fluctuating.

I'm thinking C810 might have something to do with my issue.

[Ian Paul]

Re: Vestel 17PW16-2 troubleshooting

What voltage readings do you get on the anode of D823 and pins of IC825 (one of the pins doesn't look to be soldered on this?). Both on secondary (cold) side. IC825 underneath board.

[Shotgun25]

Re: Vestel 17PW16-2 troubleshooting

What voltage readings do you get on the anode of D823 and pins of IC825 (one of the pins doesn't look to be soldered on this?). Both on secondary (cold) side. IC825 underneath board.

On the lead nearest the band on the diode, closest to the board label it reads 2.74v-2.75v fluctuating with the black probe on the ground at the far left of the board.
With the black probe nearest the transformer leg and the red nearest the board label (where the diode band is), I accidentally shorted D823 with J907, and now there is more ticking noises at various parts of the board. When I first did it the voltage increased to 3.4v fluctuating but I noticed the burning smell when the noises came so I'm guessing I've just ruined a part somewhere.

As for IC825, when I replaced it a long time ago I believe the unconnected left leg is N/C on a schematic I saw and the centre pin was connected on the original part but the schematic I used at the time showed it was the same as the metal tab. I will revisit those pins later and maybe bridge the centre pin at least, the left leg doesn't have a pad to solder to as I think it was for aesthetics and additional anchoring.

Thanks for the pointers.

[Ian Paul]

Re: Vestel 17PW16-2 troubleshooting

Re. IC825, probably just need to resolder centre pin, don't bridge it. I would now go over your board and do resistance tests across all electrolytic caps - except large ones, (obviously with board unplugged-no mains). Also all pins of ICs. Just to try and show up any shorts you may now have.

[Shotgun25]

Re: Vestel 17PW16-2 troubleshooting

Re. IC825, probably just need to resolder centre pin, don't bridge it. I would now go over your board and do resistance tests across all electrolytic caps - except large ones, (obviously with board unplugged-no mains). Also all pins of ICs. Just to try and show up any shorts you may now have.

Re: centre pin, I mean the original chip had three legs, the replacement chip had two outer legs and a stub for the centre leg, so by bridge I mean use a small run of 0.16mm enameled wire to bridge the gap.

I'll do measurements later when I've read what J907 attaches to so I have a clue what I burned.

[Ian Paul]

Re: Vestel 17PW16-2 troubleshooting

Looking at the picture re. IC825, and datasheet, the tab is connected to pin 2 (middle): http://circuits.datasheetdir.com/299...25B-pinout.jpg. Is the tab shorted to ground?

[Shotgun25]

Re: Vestel 17PW16-2 troubleshooting

Looking like C817 needs replacing. It is a 220uF @ 25V cap and it has the following readings.
Resistance Capacitance ESR
17Kohm 228.1uF 0.38

My ESR meter table for worst case acceptable values shows 0.23ESR for that rating of capacitor. I've still got to test it out of circuit but it's a start.

Also here are some values I have tested so far on various parts since last week.

F800 - not blown

R801 - 3.02Mohm (high as mentioned by Ian) - assumed ok.

C873 - 6.15Mohm - 6.26Mohm fluctuating capacitance unknown ESR unknown (too small to test)

R887 - 9.83Kohm

R881 - 81.3ohm

C817 - 17Kohm 228.1uF 0.38ESR

R1017 - 98.3ohm

C919 - 0.027Mohm capacitance unknown ESR unknown (too small to test)

C819 - 1.32Mohm 211.8uF 0.36ESR

C800 - 2.61Mohm capacitance unknown ESR unknown (too small to test)

D824 - 220v on either side of the diode.9.2Mohm then slowly drops (assume because of the capacitor C881 in series?) In diode mode 460 resistance in one direction, infinity the opposite...assume working correctly.

[Ian Paul]

Re: Vestel 17PW16-2 troubleshooting

C817 may well read lower out of circuit, in circuit may give the higher reading although I wouldn't say 0.38 ESR is poor. D824 - .460 should be the volt drop across anode to cathode, infinity other way, which seems correct.

[Shotgun25]

Re: Vestel 17PW16-2 troubleshooting

C817 may well read lower out of circuit, in circuit may give the higher reading although I wouldn't say 0.38 ESR is poor. D824 - .460 should be the volt drop across anode to cathode, infinity other way, which seems correct.

Just removed it and it reads as follows

219uF capacitance
0.28ohm ESR

Looks like it should be fine then.

Looking at the picture re. IC825, and datasheet, the tab is connected to pin 2 (middle): http://circuits.datasheetdir.com/299...25B-pinout.jpg. Is the tab shorted to ground?

Pin 1 is not connected and the pad is gone anyway.
Pin 2 has continuity with the tab (Pin4) and I have bridged the small tab of pin 2 to the pad on the board as the previous chip had that leg I believe.
Pin 3 is soldered as expected.

See attached image.

EDIT: Looks like previous chip had no middle leg, but I see no issue in the bridge I created, it's just ground right?