Hello folks, I really need help with my PG EQ215x. I have one with a fried power supply and cannot correctly identify the two mosfets that switch the primary side of the power supply. Could someone please look at theirs and help me to identify these devices so that I can rebuild my EQ. They are the only tabbed devices in the unit. They are located on the right side of the bottom circuit board, just below the transformer. Only the top cover needs to be removed to see them. Thanks
Messerschmitt
Messerschmitt
IRF 540 is the call out. IRFZ-34 will work also. These fets failed because the toroid core is shorted. they cost $7.00 each and are available form PG directly here in the US.
I have seen this several times and its always the same. the toroid windings short, then the power supply follows.
If your outside the US PG/Rodin will not answer e-mails, you must call directly. You can get their number by goggling Phoenix Gold, it will link you to the new Rodin site and look under support.
Suggestion:
These Mosfets can be mounted on the bottom of the board with their tabs resting against the back plate as a heat sink. I do this on all repairs and it works well. Use any TO-220 insulator setup you have available. This works well to aid in heat transfer, as they do get very hot to the touch in normal operation. I have zero warranty return rate doing this..... Hope this helps...
I have seen this several times and its always the same. the toroid windings short, then the power supply follows.
If your outside the US PG/Rodin will not answer e-mails, you must call directly. You can get their number by goggling Phoenix Gold, it will link you to the new Rodin site and look under support.
Suggestion:
These Mosfets can be mounted on the bottom of the board with their tabs resting against the back plate as a heat sink. I do this on all repairs and it works well. Use any TO-220 insulator setup you have available. This works well to aid in heat transfer, as they do get very hot to the touch in normal operation. I have zero warranty return rate doing this..... Hope this helps...
Think I'll hijack this thread rather than start my own, since it's so old.
I have the thing, power transistors are blown and shorted. The markings on them are:
St
P 222
9A235
Google machine told me nothing, no matter how i searched. Very frustrating... Went to post here and found this thread.
Still assuming I'm probably good to go with irf540's.
The coil thing is a bummer if true in my case... The 3 input pins ohm connected to each other and the 3 output pins ohm connected, but there is no resistance from one side to the other.
A couple of the slide pots are broken too. Looks like they are labeled "w50k". Hoping to find a source for them too.
Looks like i might be over my head this time lol....
I have the thing, power transistors are blown and shorted. The markings on them are:
St
P 222
9A235
Google machine told me nothing, no matter how i searched. Very frustrating... Went to post here and found this thread
.Still assuming I'm probably good to go with irf540's.
The coil thing is a bummer if true in my case... The 3 input pins ohm connected to each other and the 3 output pins ohm connected, but there is no resistance from one side to the other.
A couple of the slide pots are broken too. Looks like they are labeled "w50k". Hoping to find a source for them too.
Looks like i might be over my head this time lol....
No luck so far.. I dropped in irf3205 fets since I have some..
Bridging fuse and using cc supply at work, limited to 1 to 1.5a.
Fets get hot. Pos and neg 1.5v out... I'm guessing should be 12 to 18v. Also pwm seems to turn on and try to regulate without remote power.. odd.
Still finding it hard to see how xformer is bad or shorted. Nothing seems that way measuring it with an lcr etc.
I have legit parts in route from digikey. Already shotgunned the 4401 and 4403 transistors since I had some, no change. Optos seem to be functioning, but I ordered them along with a new pwm chip too to try. Total cost was relatively small...
There is no ferrite cap on the xformer. Find that kind of odd. There wasn't one loose inside the eq, but that's not to say someone wasn't in there before me.
Plan is to shoot the works and hope for the best.. I think it has to be the xformer if I have issues after. I opened pos and neg rails from the supply and that made no difference. I then supplied them with pos and neg 13 on the bench and each drew about 90ma, would say that checks out.
I'm a tech by trade.. but kinda fishing in the dark
Bridging fuse and using cc supply at work, limited to 1 to 1.5a.
Fets get hot. Pos and neg 1.5v out... I'm guessing should be 12 to 18v. Also pwm seems to turn on and try to regulate without remote power.. odd.
Still finding it hard to see how xformer is bad or shorted. Nothing seems that way measuring it with an lcr etc.
I have legit parts in route from digikey. Already shotgunned the 4401 and 4403 transistors since I had some, no change. Optos seem to be functioning, but I ordered them along with a new pwm chip too to try. Total cost was relatively small...
There is no ferrite cap on the xformer. Find that kind of odd. There wasn't one loose inside the eq, but that's not to say someone wasn't in there before me.
Plan is to shoot the works and hope for the best.. I think it has to be the xformer if I have issues after. I opened pos and neg rails from the supply and that made no difference. I then supplied them with pos and neg 13 on the bench and each drew about 90ma, would say that checks out.
I'm a tech by trade.. but kinda fishing in the dark
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Hi moer,
Can you comment on the top of the transformer and whether it should be encased too? I will rewind it if need be.
I don't suppose you could share the schematic with me?
Thanks,
Ben
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