Pv2600 replaced outputs switched on and blew a capacitor

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evertheoptimist
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Pv2600 replaced outputs switched on and blew a capacitor

Post by evertheoptimist » Sun Dec 15, 2019 4:22 am

I have a pv2600 that wouldn’t power up tested the transistors and decided to replace the lot in channel1.
After doing this I powered her up and she fired into action for about 1min then one of the reservoir caps turned into a Roman candle just wondering what caused this the pv 2600 I have is one of the newer ones with the round silver badge.

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Enzo
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Re: Pv2600 replaced outputs switched on and blew a capacitor

Post by Enzo » Sun Dec 15, 2019 12:43 pm

Usually what causes catastrophic cap failure is reverse voltage or serious overvoltage.

evertheoptimist
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Re: Pv2600 replaced outputs switched on and blew a capacitor

Post by evertheoptimist » Sun Dec 15, 2019 2:50 pm

Hey Enzo so what would cause reverse or over voltage please could you elaborate a little?

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Enzo
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Re: Pv2600 replaced outputs switched on and blew a capacitor

Post by Enzo » Mon Dec 16, 2019 8:22 pm

I have no idea what work you did on the unit, but possibly installed a cap with terminals reversed. Possibly connected cables inside the unit incorrectly. Loose hardware touching a circuit board. That sort of thing. I am not being critical of your work, I certainly have made my share of dumb mistakes. You replaced a lot of power transistors, if any were installed missing the insulating mica wafer or the silicone insulator, that can short out the power rail.

evertheoptimist
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Re: Pv2600 replaced outputs switched on and blew a capacitor

Post by evertheoptimist » Tue Dec 17, 2019 4:11 am

Ok cool I have found a couple of other bad parts but cannot source them both are resistors one is a 4K 5w resistor and the other one on the board is identified as r136 I cannot seem to source these from anywhere any help you can give would be a massive help.

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Enzo
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Re: Pv2600 replaced outputs switched on and blew a capacitor

Post by Enzo » Tue Dec 17, 2019 8:27 pm

4k 5w found several at Mouser
https://www.mouser.com/Passive-Componen ... or&FS=True

R136 is between the emitters of Q104 and Q105. It says on schematic 390 ohm 1/4 watt. That should be available anywhere that sells resistors: a common standard value in a standard wattage.
https://www.mouser.com/Passive-Componen ... 4w&FS=True

Look up "light bulb limiter", a very simple tool for your shop. Make one and use it.

evertheoptimist
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Re: Pv2600 replaced outputs switched on and blew a capacitor

Post by evertheoptimist » Wed Dec 18, 2019 12:08 am

Thanks Enzo you are a legend 😊👍

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