SWR WorkingPro 15 schem, HV specs, PT secondaries info anyone ?

[lalala]

re. SWR WorkingPro 15 bass amp 200W
I have one currently DOA, SWR WorkingPro 15 combo; upon further examination it appears to have an open PT primary(am I on the right track in assuming it popped an internal thermal fuse?)...of course I plan to next examine/ test for causes of PT failure, including output and driver devices, power supply components etc.

Already I have perused some schematics kindly provided by forum members for the WorkingMan's series. However, I have noticed some differences in the WorkingPro model on my bench:
The deceased PT appears to have triple secondaries; there are a total of 7 secondary leads, with the usual quick-connects:
1. Red pair (HV+ and HV- ?)
2. single Yellow (is this the CT for HV secondary?)
3. Brown pair
4. Blue pair

Does anybody have the WorkingPro 15 schematic and/or info on PT secondary voltages(i.e., HV, CT, LV1, and LV2) and what +/- HV the outputs should see?

This one is the 200W model SN M174xxxx and uses Sanken 2SC3519A / 2SA1386A outputs , if that helps nail it.

TIA and cheers lads

[Enzo]

Your ohm meter should confirm this: There is one secondary winding. The yellow wire is the center tap for all three pairs. 21, 23, 48vac from center.

30vDC and 70v DC plus 15v Vreg circuuits

[lalala]

Your ohm meter should confirm this: There is one secondary winding. The yellow wire is the center tap for all three pairs. 21, 23, 48vac from center.

30vDC and 70v DC plus 15v Vreg circuuits

Exactly what I needed to know- thanks Enzo.

Extracted the PT a couple minutes after i posted about the SWR, and found out it has just one winding with multiple taps, as Enzo pointed out. Couldn't find any evidence of transformer overheating, nor any blown outputs etc.; I take it the thermal fuse did its job, perhaps prematurely. Such a major component teen suicide sure seems like a big waste of iron/copper potential though, and the high replacement cost makes these amps virtually disposable in practice. There are available other, larger transplant candidates with similar V sec windings and higher current ratings. Main problem looks to be space and cooling(only a 2U chassis to work with, so no tall PTs will fit).

SWR sure isn't helping their cause with an inexplicable reluctance in supplying tech docs. The 'mother may I' system they have is so pre-www.1990s man. Still waiting to hear back from SWR for schems, where if they just had a normal Support>Download link for tech docs, that amp of theirs would probably be out there gigging/advertising the Co. name by now...
After all, their corporate overlords at Fender have most of their own amp schematics readily and openly available via download. Doesn't seem to hurt Fender's rep or amp sales either does it?

[Enzo]

Oh, relax.

Most companies don't publish their transformer specs.. A small few do. The only reason someone would need that information would be so they could stuff SOMETHING ELSE into one of their amps. SWR/Fender has no interest in promoting that. ANy more than Ford would suggest ways to stuff a Chevy engine into one of their cars. Fender makes the exact parts available as replacements in most cases. Someone needs a new transformer, the part number is all the specs one needs.

Not sure how many companies have the schematics online, my impression is the mninority of them. PV will send you anything, but they are not sitting online. Fender has a collection of most popular amps online, but will send most anything else. The Loud folks don;t keep the Crate and Ampeg drawings online. Marshall doesn;t do they? Samson doesn;t put theirs and Hartke's online, but they will send them. Yamaha, Roland, TEAC/TASCAM sill SELL you a nice manual. Behringer? Forget it. Line 6? Not on your life. Not sure where a schematic database online is normal.

As a technician, sure, I'd think it lovely if I could get anything I want instantly. But to a company like Fender, civilians needing schematics is such a tiny tiny part of their market.

[J M Fahey]

Dear lalala.
Don't know where you live.
If in USA, try to get a replacement transformer from SWR/Fender.
I'm in Argentina, so that's impossible: international freight + Customs taxes don't allow it, so *I*, in my particular situation, would try to re-enable it.
The thermal fuse can be ordered from DigiKey and certainly from many others
Thermal Fuse
If buried in the middle of the primary winding, I'd forget it; but if added after fully winding, it might be just below the outer layer of insulating paper.
I might try to feel its bump with my fingers and *carefully* slit said paper open, avoiding scratching the wire enamel or insulation or I'll have a shorted or electrically leaking transformer .
I'd replace it with a same specs one.