Seleco Sim2 SVP 350 Dead...

J

Jon J

Guest
Hi guys :hiya:

Today I was handed a dead SVP 350. (When I say "handed", I mean more like crushed by). I've been asked if I can fix it as a favour for a local club where it was working until very recently... (so it died whilst in situe on the ceiling).

I'm just wondering if any of you kind soles here can give me any pointers as to where to look first for typical dead faults in this beast?... I gather this is not an uncommon fault with these?

(It is completely & utterly dead with no sigh at all of any powerup)

I haven't delved into it very deep yet, other than checking that the mains is actually getting in and that the 2 fuses on the back are AOK... I've read in these forums that some of the boards do come loose which is the first thing I'll be checking out as soon as I can.

Meanwhile I'd be truly greatful for any pointers anyone might be able to offer... :lease:
 
J

Jon J

Guest
Hi again,

I've done a quick check and the PSU panel at the front under the lenses seems to be the culprit. (Mains coming in to panel - nothing coming out - the PSU fan isn't even working).

Also just noticed that it's an SP 350 Plus if that makes any difference...

Anyone know if any components on this panel commonly go?!

OK I'm begging now, look at me, is this what you wanted?! :rolleyes:

Thanks Jon :)
 
J

Jon J

Guest
Hi Chris!

Thanks for the response...

No LED's lit up, no sign of life anywhere...

(I haven't got the PSU board out yet, but I know mains is coming in to it OK)
 

Chris Frost

Well-known Member
Check the two small plug-in cards are seated correctly. The smaller one is the standby controller, the larger is the switchmode PSU controller.

After that, have a look for a light blue coloured 22 Ohm resistor near the circular transformer close to where the mains comes on to the PSU board. I've seen boards where that has popped. Try measuring the resistance.
 
J

Jon J

Guest
Thanks a million for the priceless info Chris :)

I'll try that tomorrow and let you know how I got on...
 
J

Jon J

Guest
Hi Chris :)

I've just got the PSU out and instantly noticed a blown resistor right where you mentioned. Infact it's got a lovely hole in the side! :thumbsup:

Thanks a million for you pointer. I've checked around the resistor with a meter and there doesn't appear to be any other problems (I know - I'll regret saying that).

The only thing puzzling me is now is that you mentioned a 22ohm resistor, but I've got a 0.12ohm resistor: It's definately Brown/Red/Silver/(Gold)

Make sense to you?


Here's some pictures for reference and also for the next poor sole googling for some answers :)


attachment.php



attachment.php



Now, to search the junk filled shed for a .12ohm resistor - I may be gone some time!
 
J

Jon J

Guest
OK, with the resistors I had available I had to put the following together in parallel (.22/1.2/1.2/1.2/1.2) to roughly make 0.12ohm (Just to as a test b4 I order the proper component)...

Anyhow they all just got instantly fried! :eek:

So something must be seriously shorted out somewhere near by.

I'll go over the board... any ideas from anyone?

...Thanks again

PS. Don't suppose anyone's got a diagram / component list for this board & the two plugins?
 
J

Jon J

Guest
Thanks to both of you... :)

Chris, I've PM'd you - Thanks!

MR Mad H, thank you also, I might well be interested in some bits if I find that I can't fix at component level. (Though I'm doing this as a favour for someone, so I'd have to check with them first re. any possible cost...)

Anyone know if the PSU of an SVP350 the same as in a this SVP350 Plus?

So far there's no obvious signs of anything short on the PSU board, but I'm sure there must be for the primary stage to blow so quickly like that...
 

Mad Mr H

Well-known Member
Check the FAQ,

there is a Seleco thread there...........

LOOK at the PCB numbers on the PSU's

IF you find NEW numbers not listed in that thread plase forward them to me.........

I did my best to list as many as I could to help others, any new info will I hope help others in the future.
 
J

Jon J

Guest
Hi again Mad Mr H!

That's a great thread you've got going, but I can't find any board info for this model, so here goes:

The unit is a (Sim2) Seleco SVP350 Plus

The PSU is marked "PC195.0" & "C 60.3417.100"

The "Switch Mode Control" module is marked "PC 196.0" & "C 60.3421.100"

The "Stand-By Control" module is marked "PC 197.0" & "C 60.3423.100"

Hope this helps someone some day!
 
J

Jon J

Guest
Hi guys,


I think I'm making a little progress now after finally finding the time to go over the PSU properly...

Anyhow, now I'm looking for a UK supplier for a "H15NB50FI".

It's a three legged Power Mosfet on the main heatsink (T101)... I believe it may well be short circuit - (or maybe not!) All I know is that no matter how I measure it I'm getting a TOTAL short (.000) between two legs & .059 between any other combination. It's also in line with everything else that I've found OC...

I've managed to download the technical data for one of these, but haven't yet been able to find a UK source... Just wondering if any kind soles here might know of one?

Thanks :)
 
J

Jon J

Guest
OK guys, with some very kind help from Chris Frost I'm really pleased to report that the SVP350 Plus in question has now been brought back from the dead!

Yep, it's working perfectly - here it is in action!

crt-working.jpg



So for the forum, and also any poor sole out there with a dead SVP350 (plus) lucky enough to google this way, here's a list of duff parts replaced for this particular fix:

(R404) 1x 680 surface mount resistor

(R405) 1x 2.7K surface mount resistor

(IC401) 1x L4981b (Farnell Part No. 3236092)

(R102) 1x .12ohm wire wound resistor (best replacement I could find was ultimately Farnell Part No. 1219239)

(T101) 1x H15NB50FI MOSFET / A very hard to find component so succesfully replaced with suggested equivalent: STW14NM50* (RS Stock No 419-2434)

*The replacement MOSFET has a slightly different casing with a metal back (the original was all insulated). So an appropriate insulator was required to keep it from making electrical contact with the heatsink.

There you go, my humble thanks Chris and all who have helped in this forum...

:clap:
 

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