Phoenix Gold RX500.1 NEED HELP TRACKING A RESISTER I GOT A amp with blown parts there is a tip42c and a tip41c mosfet there is a resister that goes from the first leg of tip42 as mine is blown to bits and dont know the colour code or whats of the resister if its 1w 4w 5w i know it starts with gold or ends with gold anyway was hoping some one as the same amp and could take a really good pic fore me of the driver section of the amp i have replaced all damaged parts but stuck on the damaged resister that i carnt work out what it is
Post a photo of the entire board and another close-up of the area with the resistor and nearby components.
Tip 42c and Tip 41c sound like driver transistors which are bipolar or BJT transistor.
basically complementary pair.
Since its basically complementary amplifier and the pnp side blew up.
just look at the npn tip41 side for the resistor value.
gold band is 5% resistor tolerance
basically complementary pair.
Since its basically complementary amplifier and the pnp side blew up.
just look at the npn tip41 side for the resistor value.
gold band is 5% resistor tolerance
Thank you i have done some research online and could only find one video of some one taking the lid of the same amp how ever I carnt get a clear image of the area but it looked like the resister was a biggish light blue metal film resister kind of looked like brown black brown gold or as I seen it gold brown black brown it was hard to tell but the track runs strate to tip42c emitter leg I did put a 100 ohm resister there and the amp powers up fine but plays like ots under water muffled sound
Will do Perry thank you for replying to me I have a picture I found online steveemeade designs onyoutube shows the inside of the amp but carnt get a clear image of the resister will send a pic that I got from it aswell
here is a picture i found online the only one i could get my hands on doing research
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HI sorry i wanted to show you a picture of a whole board mine currently as the 649A and 669A resisters removed awaiting my replacments also the red wire you see is where i had to repair a damaged track from the blown area here are some of my board thank you for your time
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I can't help. If no one else helps, try the following forum:
https://www.phoenixphorum.com/viewforum.php?f=3
https://www.phoenixphorum.com/viewforum.php?f=3
as with any amplifier output section failure.
sometimes damaged components are replaced
and amplifier will resume working.
but other components might have been damaged.
the amplifier likely has current limiting / VI limiters
which could be simple single slope or multi slope.
point is there is usually multiple diodes/resistors in the limiter that could be damaged.
or often VI limiters will have capacitors to slow the response when operating.
I cant tell exactly by the board, but can see some diodes and few surface mount
capacitors / resistors which were likely part of the limiter section.
looks like the VI limiter transistors might have been removed.
which could solve the problem. but if any diodes or resistors have failed closed
they could still cause issues.
you would have to repair the VI limiters, or lift/remove any diodes/resistors/capacitors
involved with the circuit.
likely there is diodes / resistors/ capacitors failed closed in the limiters. so removing VI limiter transistors
would not completely remove the failed limiter section
transistors are more likely to fail closed. but can fail open.
be good to check all output devices for open
also check large ceramic emitter resistors for high drift or open.
looks like tip41/42 driver transistors and tip 35c/36c output transistors
sometimes damaged components are replaced
and amplifier will resume working.
but other components might have been damaged.
the amplifier likely has current limiting / VI limiters
which could be simple single slope or multi slope.
point is there is usually multiple diodes/resistors in the limiter that could be damaged.
or often VI limiters will have capacitors to slow the response when operating.
I cant tell exactly by the board, but can see some diodes and few surface mount
capacitors / resistors which were likely part of the limiter section.
looks like the VI limiter transistors might have been removed.
which could solve the problem. but if any diodes or resistors have failed closed
they could still cause issues.
you would have to repair the VI limiters, or lift/remove any diodes/resistors/capacitors
involved with the circuit.
likely there is diodes / resistors/ capacitors failed closed in the limiters. so removing VI limiter transistors
would not completely remove the failed limiter section
transistors are more likely to fail closed. but can fail open.
be good to check all output devices for open
also check large ceramic emitter resistors for high drift or open.
looks like tip41/42 driver transistors and tip 35c/36c output transistors