Porta B (L100P) blows fuses

[thysm00]

Hi everyone,

I have a porta B (L100P depending on the country it was made) that just stopped working a week ago while i was recording it.

I started making an increasing low frequency until it was at the volume of the notes i was playing. So i turned it off, let it cool off a little and then when i tried to start it again, i just vlew the fuses in my studio... two times.

Does anyone know what i can do to troubleshoot this? I was recording it and it just stopped right in the middle and it seems to be absolutely impossible to find one in a studio over here in France... Not even a L100, even less with a line out (i have made the line out under the swell pedal mod).

[Drawbar Dave]

If the power supply section has never been serviced, I would start there replacing the electrolytic capacitors.

[Jyvoipabo]

Bonsoir,

Je résume : Le machin a produit une fréquence de plus en plus basse, puis le fusible à fumé.

Cela ressemble au condensateur de démarrage du moteur qui a rendu l'âme. Comme celui qui est sur la photo jointe. C'est assez fréquent.
Ca gonfle. Parfois il y a fumée blanche mais ça fait pas conclave car c'est très toxique.

Il me semble que c'est un condensateur au PCB (pyralène) 1µ25 / 630V à ne pas remplacer par n'importe quoi.

JP

[thysm00]

Bonsoir,

Je résume : Le machin a produit une fréquence de plus en plus basse, puis le fusible à fumé.

Cela ressemble au condensateur de démarrage du moteur qui a rendu l'âme. Comme celui qui est sur la photo jointe. C'est assez fréquent.
Ca gonfle. Parfois il y a fumée blanche mais ça fait pas conclave car c'est très toxique.

Il me semble que c'est un condensateur au PCB (pyralène) 1µ25 / 630V à ne pas remplacer par n'importe quoi.

JP

Merci beaucoup! Je vais tenter ça, est-ce que tu pourrais me dire déjà ou en trouver un, et surtout, à quel endroit il se situe dans la machine pour ne pas tout désosser pour rien ;)
Est-ce que j'ai moyen sans mettre l'orgue sous tension de tester si c'est bien lui qui est mort par exemple avec un ohm mètre?

PS: je ne reçois pas de notification de réponse... du coup je n'avais pas vu ta réponse...

[thysm00]

If the power supply section has never been serviced, I would start there replacing the electrolytic capacitors.

That might be a good idea, but i've heard that bad capacitors in there usually change the overall pitch of the organ, but i haven't see anything related to these that blows the fuses when you try to start it.
#Jyvoipabo 's answer makes sense though, as i have seen multiple threads talking about this run capacitor giving similar problems.
Now i just need to find a replacement one.

[Jyvoipabo]

The capacitors 1.25μF 630V are very difficult to find.
On the other hand we find everywhere 2.5μF 450V
So called permanent motor starting capacitor.
Just buy 2 and wire it in series with a paralell resistance of 220k / 2W on one of them for the discharge purpose.

JP

As in the attached pic, you can run a ground wire from the motor to the TW frame. This can reduce electrostatic noise.
And not shown a plastic screen for safety.

[thysm00]

Ok, thanks, it does seem easy enough! From your picture, i'm guessing the original cap is in the top compartiment. I'll check that tonight.

[enor]

That might be a good idea, but i've heard that bad capacitors in there usually change the overall pitch of the organ, but i haven't see anything related to these that blows the fuses when you try to start it.
.

The power supply capacitors in the amplifier have nothing whatsoever to do with the pitch of the organ.

[Wes]

Celui la marcherais probablement comme il faut - https://www.mouser.ca/ProductDetail/Illinois-Capacitor-CDE/125MABA03KHS

[thysm00]

That might be a good idea, but i've heard that bad capacitors in there usually change the overall pitch of the organ, but i haven't see anything related to these that blows the fuses when you try to start it.
#Jyvoipabo 's answer makes sense though, as i have seen multiple threads talking about this run capacitor giving similar problems.
Now i just need to find a replacement one.

Well, that did the trick!!!! I just removed the old one, put those two new 2.5uF capacitors in series with a 220k resistor in parallel on one of them as you advised and it just started spinning like before ;) I can't believe how cheap (around 10€) and easy that was! Now i just need to find out what to do with these 9 remaining 220k resistors ;)

Thanks a lot! I can get back to recording it!