Wharfedale L32TA6A - Phihong PSM210-417A R issue

[dervdub]

Hi all, it's been a while.

I've got a friends Wharfedale L32TA6A that won't start up, I just get alternating red/blue LEDs on the front panel and a slight 'fitzzz' sound from the primary on the PSU when you power on (the set is unresponsive once asked to power on)

STBY 5v is good at 5.04v but the 24v line comes up to 8v then tails off slowly and the 12v line starts at 3v and tails off. What I believe to the mains smoothing cap is slightly bulged so needs replacing.

F101 is good, IC101 has no tell tail which is pin 1 (or 6 and 8) to test for a short there as per the kit instructions - and if I'm honest I'm not good enough at electronics to work out any further.

I've done much searching and all symptoms found so far don't match these, I read a post where another post was mentioned with 3 separate PSU's being used, but I can find no details on this mod.

Any help will be much appreciated and I'm happy to spend a few quid in the right place to get it sorted.

Thanks

Andy

[jordan]

C-915 (150uF/400V) on PSU

[dervdub]

Thanks for that, I changed a 180uf 450v capacitor on the hot side of the PSU (C103?? - I can't tell for sure as there is bonding agent in the way of the last character)

Still the same, although the fitzzz noise is slightly less now.

[Restorer79]

Let us know what happens when you've changed C915.




Andy

[dervdub]

Let us know what happens when you've changed C915.

Andy

Sorry, my last post was a little vague - I cannot find a C-915 on the PSU to change, but there was a C10? that was rated 180uf/450v)

Given that a 150uf/400v (or 180uf/450v) cap is quite a size in relation to the other components it should stick out like a sore thumb - I've been all over the board 5 times with a magnifier looking for C-915 and I cannot find it.

Hopefully I'm being really stupid and it's there somewhere - I'm wondering if this is a case of mistaken (PSU) identity as there is an AR version (which I have) and a non AR version (Bauer/Haier etc)

I've checked both KIT74 & KIT75 on CHS and can find no mention of C-915

EDIT: I've just been over the PSU twice more with a magnifier and cannot find C-915, there is a C-615, but it's on the secondary side.

Any ideas?

[ANDRASONI]

Change all electrolytics caps( uF values) on the PSU. Succes!

[dervdub]

Any more suggestions chaps? While I'm tempted to blindly fit new caps all round, I'm not sure there is much value in doing so - particularly as the 5v STBY is happy, but the 12/16/24v lines aren't and they spend much less time in action.

These seem to be a popular PSU, but I can't find one to buy and there's no info on them.

Hopefully Turnip knows something about them, I feel cheeky PM'ing him as I don't often get on here.

[daz]

Hi
I did one not so long ago (similar fault) where every cap was leaky or had a high esr,
I know its a pain as every one just looks for bulgy caps these days but you need to change them all.
Good luck
Daz

[cdel]

hi,
just want to know if there is 16volts written on your board ,as i know 24,12,&5 only.

[dervdub]

Daz, thanks for the post - I've had to order some of the odd sized caps in so am awaiting delivery of those and will let you know my findings.

Cdel, It's not screen printed on the board itself but there is 5VS, 12V and 24V, but there is VADJ printed on the board.

It does mention the 16.5V line on the PSU label though - maybe the 16.5V 2A mentioned comes from the VADJ terminal (the set is in bits and some caps missing now so can't power it up)

I was tempted to inject 12 & 24v to see what happens, but chickened out as it's not my set.

[cdel]

hi,
the reason why i asked is i have been same problem in that but because the cost is expensive,i use MLT668 that is available on my racks did some easy modification till now tv is ok.hope it may help.

[dervdub]

I've replaced all the caps and it's still the same.

The MLT668 psu you mention, does this have the 16v line?

[cdel]

no only 5v,12 and 24.

[dervdub]

Hi cdel,

Sorry I might be being a little thick here, I can't tell from the thread if the TV needs the 16v line or not, are you saying the PSU you mention will work fine if wired correctly?

Thanks

Andy

[Ohm Supplies]

hello,

The board might be marked 16v but you might only get 15v from it, this is normal

regards
ANdy